BERKELEY 
lERARY 

WVEBSM7  or 

CALIFOBMrA 


FROM   THE  OPTOMCTRIC  LIRRARY 
OF       

MONROE    JEROME    HIRSCH 


J^/l 


THE  LIBRARY 

OF 

THE  UNIVERSITY 

OF  CALIFORNIA 


GIVEN  WITH  LOVE  TO  THE 

OPTOMETRY  LIBRARY 

BY 

MONROE  J.  HIRSCH,  O.D.,  Ph.D. 


DISEASES    OF    THE    EYE 


SWANZY'S  HANDBOOK 


DISEASES  OF  THE  EYE 


AND   THEIR 


TREATMENT 


EDITED    BY 

LOUIS  WERNER,  M.B.,  F.R.C.S.L,  Sen.  Mod.  Univ.  Dub. 

SURGEON      TO      THE      ROYAL      VICTORIA      EYE       AND      EAR      HOSPITAT, 

OPHTHALMIC     SURGEON     TO     THE     MATER     HOSPITAL,     PROFESSOR     OF 

OPHTHALMOLOGY,    UNIVERSITY    COLLEGE,    DUBLIN,    AND    EXAMINER   IN 

OPHTHALMOLOGY,    DUBLIN   UNIVERSITY 


ELEVENTH   EDITION 
WITH  ILLUSTRATIONS 


LONDON 

H.   K.    LEWIS,    136    GOWER   STREET,    W.C. 

1915 


OPTOMETRY 


"(f^  dC 


London 

H.   K.   LEWIS,   136   GOWER   STREET,  W.C. 


PREFACE 


oero 


In  this  edition,  the  first  which  has  appeared  since  the  death  of  my 
esteemed  friend  and  colleague  the  late  Sir  Henry  Swanzy,  I  have 
carefully  avoided  making  any  change  in  the  general  plan  or 
character  of  the  book. 

The  text  has  again  been  completely  revised  and  brought  up  to 
date,  with  the  result  that  a  considerable  amount  of  new  matter  has 
been  incorporated,  but  without  any  notable  increase  in  the  number 
of  pages. 

The  Chapter  on  the  Pupil,  which  was  omitted  in  the  last  edition, 
has  now  been  restored  to  its  place.  In  the  chapter  on  Glaucoma, 
the  trephine  operation  has  been  dealt  with  in  greater  detail,  and  a 
description  of  Schiotz's  tonometer  has  been  added.  The  Diseases 
of  the  Retina  have  been  to  some  extent  re-arranged  ;  Hsemorrhagic 
Retinitis  is  no  longer  treated  as  a  separate  entity,  but  is  referred  to 
under  Thrombosis  of  the  Retinal  Vein,  while  a  separate  paragraph 
is  allotted  to  Retinal  Haemorrhages  in  general ;  Angio-sclerosis  and 
obstruction  of  the  Retinal  Circulation  receive  more  attention  than 
heretofore,  and  Capillary  Angiomatosis  of  the  Retina  and  Massive 
Exudation  are  briefly  described. 

The  chapter  on  Nystagmus  has  been  altered  and  amplified,  and 
now  includes  a  brief  account  of  Vestibular  Nystagmus. 

Numerous  minor  improvements  and  additions  have  been  made, 
amongst  which  may  be  mentioned  the  introductory  paragraphs  to 
Chapters  V,  VI,  X,  and  XIX,  the  articles  on  CEdema  of  the  Eyelids, 
Artificial  Eyes,  Maddox's  Wing  Test  for  Heterophoria,  etc.  Many 
new  illustrations  have  also  been  added. 

I  have  again  to  thank  Dr.  Kathleen  Lynn  for  the  care  and  trouble 
which  she  has  taken  in  the  preparation  of  the  index. 

L.  Werner. 
31,  Merrion  Square, 
Dublin. 


PREFACE  TO  THE  TENTH  EDITION 

In  the  present  edition,  as  in  the  previous  ones,  the  endeavour  has 
been  to  keep  the  book  abreast  of  modern  ophthalmology,  in  so  far 
as  this  is  possible  in  a  work  of  its  size,  mainly  intended  for  students. 
The  amount  of  text  is  about  the  same  as  before,  although,  in  con- 
sequence of  an  alteration  in  the  shape  of  the  book,  the  number 
of  pages  is  less.  The  chapters  are  differently  arranged,  with  the 
result  that  the  earlier  ones  now  treat  of  the  normal  eye  and  its 
functions,  and  the  methods  for  examining  them.  The  book  has 
been  thoroughly  revised  throughout,  obsolete  matter  having  been 
discarded,  while  new  developments  have  been  introduced.  The 
book  now,  for  the  first  time,  contains  coloured  figures,  to  the  number 
of  twenty-one,  from  original  paintings  by  one  of  us  (L.  W.),  and 
it  is  believed  that  these  w^ill  prove  helpful  to  the  student. 

Our  thanks  are  due  to  Dr.  Kathleen  Lynn  for  the  great  pains 
she  has  taken  in  the  preparation  of  the  index. 

We  desire  also  to  express  our  thanks  to  Mr.  H.  K.  Lewis  for 
the  care  he  has  given  to  the  production  of  the  book  and  for  his 
readiness  to  carry  out  all  our  suggestions. 

H.  R.  S. 
L.  W. 

Dublin, 


CONTENTS 


CHAPTER    I. 

PAGE 

Preliminary  Note  on  the  Clinical  Examination  of  Eye  Patients         .  1 

Optical  Structure  and  Functional  Examination  of  the  Eye       .  .  2 

Refraction — Accommodation — The  Mechanism  of  Accommodation 
— The  Far  Point  and  the  Near  Point — The  Amplitude  and 
Range  of  Accommodation — Connection  between  Accommodation 
and  Convergence  (Relative  Accommodation)^ — Convergence — 
Range  and  Amplitude  of  Convergence     .....  4 

The  Sense  of  Sight  (Light- Sense,  Colour- Sense,  Form- Sense)     .  .        10 

The  Field  of  Vision — Perimetry — Pathological  Defects  in  the  Field 
of  Vision — Perception  of  Colours  in  the  Periphery  of  the  Field 
• — Perception  of  Form  in  the  Periphery  of  the  Field  .  .  .17 


CHAPTER    11. 

THE    OPHTHALMOSCOPE. 

Laws  of  Reflection— Images  formed  by  Plane  and  Concave  Mirrors 

— How  to  distinguish  Plane  and  Concave  Mirrors     .  .  .26 

The  Ophthalmoscope — Why  Necessary — Helmholtz's  Ophthalmo- 
scope— Modern  Ophthalmoscope  — Direct  Method — Indirect 
Method 27 

Detection  of  Opacities  in  the  Refractive  Media  by  aid  of  the  Oph- 
thalmoscope .........         35 

The  Normal  Fundus  Oculi  as  seen  with  the  Ophthalmoscope — The 
Optic  Disc  or  Optic  Papilla — The  Retina — The-  Macula'  Lutea — 
The  General  Fundus  Oculi — The  Retinal  Vessels        ...        36 


CHAPTER    III. 

DISEASES    OF   THE    CONJUNCTIVA. 

Preliminary  Note — The  Examination  of  the  Conjunctiva  .  .        42 

Hypersemia  —  Conjunctivitis  in  General  (Causes  —  Diagnosis — 
Varieties) — Bacteriology  of  Conjunctivitis — Catarrhal,  Simple, 
Acute,     or     Muco-purulent      Conjunctivitis — Diplobacillary     or 


CONTENTS 


Angular  Conjunctivitis — Chronic  Simple,  or  Chronic  Ca- 
tarrhal, Conjunctivitis — Acute  Blennorrhoea  of  the  Conjunctiva, 
or  Purulent  Ophthalmia — Membranous  Conjunctivitis  (Croupous 
and  Diphtheritic) — Hay  Fever — Trachoma.  Granular  Con- 
junctivitis, or  Granular  Ophthalmia  (Acute  and  Chronic) — Fol- 
licular Conjunctivitis — Tubercular  Disease — Parinaud's  Con- 
junctivitis —  Ophthalmia  Nodosa  —  Sporotrichosis  —  Lupus  — 
Syphilis — Ulcers  of  the  Conjunctiva — Spring  Catarrh,  or  Vernal 
Conjunctivitis  —  Pemphigus  —  Conjunctivitis  Petrificans  —  Sub- 
conjunctival Ecchymosis — Subconjunctival  Serous  Effusion,  or 
Chemosis  —  Emphysema  —  Injuries  —  Degenerative  Diseases  — 
Pinguecula — Epithelial  Plaques — Pterygium — Lithiasis — Xerosis 
or  Xerophthalmia — Hj^aline,  Colloid,  and  Amyloid  Degeneration  93 
Cysts — Simple  Cysts — Sub-conjunctival  Cysticercus          .           .  .98 

Tumours — Dermo-Lipoma — Osteoma — Naevus,  or  Mole — Hseman- 
gioma — Polypus  and  Granuloma — Lj^iiphoma — Papilloma,  or 
Papillary  Fibroma — Epithelioma — Sarcoma — Tumours  of  the 
Caruncle 99 


CHAPTER    IV. 

PHLYCTENULAR    CONJUNCTIVITIS    AND    KERATITIS. 

Solitary,  or  Simple,  Phlycten  of  the  Conjunctiva — Multiple,  or 
Miliary,  Phlyctens  of  the  Conjunctiva — Primary  Phlyctenular 
Keratitis 102 


CHAPTER    V. 

DISEASES    OF   THE    CORNEA. 

Introduction        .  .  .  .  .  .  .  .  .  .110 

Clinical  Methods  of  Examining  the  Cornea     .  .  .  .  .110 

Inflammations  of  the  Cornea — (a)  Ulcerative  Inflammations — Simple 
Ulcer — Deep  Ulcer — Serpiginous  Ulcer — Marginal  Ring  Ulcer — 
Diplobacillus     Ulcer — Rodent     Ulcer — Keratomalacia — Neuro- 
paralytic   Keratitis  —  Herpes    Corneae    Febrilis  —  Dendriform 
Keratitis — Bullous  Keratitis — Filamentary  Keratitis — Keratitis 
Aspergillina  .  .  .  .  .  .  .  .  .112 

(6)  Non-Ulcerative  Inflammations — Abscess — Ring  Abscess — 
Syphilitic     Diseases     (Diffuse     Interstitial     Keratitis — Specific 
Punctiform      Interstitial      Keratitis — Gumma) — Nodular,      and 
Reticular  Keratitis — Discoid  Keratitis — Tubercular  Keratitis — 
Keratitis  Punctata — Sclerotising  Opacity — Ribandlike  Keratitis 
— Superficial  Epithelial  Dystrophy  .  .  .  .  .136 

Ectasies    of    the    Cornea — Staphyloma — Conical    Cornea — Atrophic 

Marginal  Degeneration  .  .  .  .  .  .  .  .146 

Tumours  of  the  Cornea       .  .  .  .  .  .  .  .153 


CONTENTS 


Injuries  of  the  Cornea — Foreign  Bodies — Losses  of  Substance,  or 
Abrasions — Recurrent  Abrasion,  or  Disjunction — Haemorrhagic 
Discoloration — Blows — Injuries  with  Caustic  Substances — Per- 
forating Injuries  .  .  .  .  .  .  .  .  .153 

Opacities  of  the  Cornea — Nebula,  Macula,  Leucoma — Arcus  Senilis      160 

CHAPTER   VI. 

DISEASES    OF   THE    SCLEROTIC. 

Introductory  —  Episcleritis  —  Deep  Sclerotis  —  Gumma — Tubercle  — 

Brawny  Scleritis  .  .  .  .  .  .  .  .164 

Tumours — Pigment  Spots     .  .  .  .  .  .  .  .168 

Injuries      .  .  .  .  .  .  .  .  .  .  .168 

Staphyloma — Coloboma — Congenital   Defects  .  .  .  .171 

CHAPTER    VII. 

DISEASES    OF   THE    UVEAL    TRACT. 

Inflammations  of  the  Iris,  or  Iritis — Acute  Iritis     .  .  ,  .173 

Syphilitic — Gonorrhoeal — Tubercular — Rheumatic  .  .  .177 

Chronic  Iritis  or  Irido-cyclitis         .  .  .  .  .  .  .183 

Inflammations  of  the  Ciliary  Body,  or  Cyclitis — Acute — Chronic — 

Syphilitic — Gumma — Tubercular  Cyclitis  .  .  .  .187 

Inflammations  of  the  Chorioid,  or  Chorioiditis — Disseminated — 
Central  Senile  Guttate — Central — Syphilitic  Chorioido-Re- 
tinitis — Purulent  Chorioiditis  .  .  .  .  .  .189 

Sympathetic  Ophthalmitis  and  Sympathetic  Irritation — Injuries 
of  the  Iris — Foreign  Bodies — Iridodialysis — Retroflexion — Rup- 
ture of  the  Sphincter — Dehiscence — Aniridia — Mydriasis  and 
Miosis •  .       193 

Injuries    of    the    Ciliary    Body — Punctured    Wounds    and    Foreign 

Bodies  .  .  .  .  .  .  .  .  .  .214 

Injuries  of  the  Chorioid — Foreign  Bodies — Incised  Wounds — Rupture 

— Extravasation  of  Blood       .  .  .  .  .  .  .214 

New  Growths  of  the  Iris — Cysts — Granuloma — Solitary  Tubercle — 

Sarcoma — Carcinoma — Ophthalmia  Nodosa     .  .  .  .216 

New  Growths  of  the  Ciliary  Body — Sarcoma — Myosarcoma — Car- 
cinoma .  .  .  .  .  .  .  .  .  .217 

New  Growths   of   the   Chorioid — Sarcoma — Carcinoma — Tubercle — 

Sarcoma  .Carcinomatosum,  Osteo-Sarcoma,  and  Lymphoma      .      217 

Other  Diseases  of  the  Chorioid — Posterior  Staphyloma — Detach- 
ment— Central  Senile  Areolar  Atrophy     .  .  .  .  .221 

Malformations  of  the  Iris — Heterophthalmos — rCorectopia — Polycoria 

— Persistent  Pupillary  Membrane — Coloboma  .  .  .223 

Malformations  of  the  Chorioid — Coloboma — Alterations  in  the  Colour 

of  the  Iris — Albinismus  .......      224 

Operations  on  the  Iris  .  .  .  .  .  .  .  .225 


CONTENTS 


CHAPTER    VIII. 

THE    PUPIL. 

pa(;e 
Contraction  of  the  Pupil — Dilatation  of  the  Pupil — Action  of  Mydri- 
atics— Action  of  Miotics         .  .  .  .  .  .  .229 


CHAPTER   IX. 

GLAUCOMA. 

Primary  Glaucoma — Schiotz  Tonometer — Chronic  Simple  Glaucoma — 
Acute  Glaucoma — Subacute  Glaucoma — Etiology — Pathology — 
Treatment    ..........      235 

Secondary  Glaucoma — Haemorrhagic  Glaucoma       ....      258 

Congenital  Glaucoma,  or  Hydrophthalmos     .....      260 

CHAPTER    X. 

DISEASES    OF    THE    CRYSTALLINE    LENS. 

Introduction — Complete  Cataracts — Senile  Cataract — Complete  Cata- 
ract    of      Young      People — Diabetic      Cataract — Glass-Blower's 
Cataract — Black  Cataract      .  .  .  .  .  .  .201 

Partial  Cataracts — Central  Cataract — Zonular,  or  Lamellar,  Cataract 
— Punctate  Cataract — Anterior  Polar,  or  Pyramidal  Cataract — 
Fusiform,  or  Spindle-shaped  Cataract — Posterior  Polar  Cataract      269 
Secondary    Cataract — Posterior    Polar    Cataract — Total    Secondary 

Cataract       ..........       272 

Capsular  Cataract        .........       273 

Traumatic  Cataract     .  .  .  .  .  .  .  .  .273 

Operations      for      Cataract — Extraction — Linear      Extraction — The 
Combined     Operation — Extraction     without     Iridectomy — Ex- 
traction in  the  Capsule  .  .  .  .  .  .  .275 

Discission  ...........       293 

Dislocation  of  the  Lens         .  .  .  .  .  .  .  .294 

Congenital   Defects    of    the    Lens — Ectopia — Coloboma — Lenticonus 


9( 


Aphakia     ...........       295 

CHAPTER    XL 

DISEASES    OF   THE    VITREOUS    HUMOUR. 

Purulent  Inflammation — Other  Inflammatory  Affections — Haemor- 
rhage— Muscae    Volitantes — Synchysis — Synchysis   Scintillans    .       298 

Foreign  Bodies — Rontgen  Rays  for  Detection  of  Foreign  Bodies — 

The  Sideroscope — Removal  of  Foreign  Bodies — The  Magnet     .      303 

Cysticercus — Blood  Vessels — Persistent  Hyaloid  Artery  .  .  .311 


CONTENTS 


CHAPTER    XII. 

DISEASES    OF   THE    RETINA. 

PAGE 

Alterations  in  the  Retinal  Circulation — Hyperemia  and  Anaemia — 

Pulsation  of  Vessels       .  .  .  .  .  .  .  .313 

Inflammations — Retinitis — Syphilitic,    Albuminuric,    Diabetic,    Leu- 

coemic,  Metastatic  .  .  .  .  .  .  .  .314 

Retinal  Haemorrhages  and  Allied  Diseases — Retinitis  Proliferans — 
Retinitis  Exudativa — Retinitis  Circinata — Capillary  Angio- 
matosis        ..........       320 

Diseases  of  the  Retinal  Vessels — -Sclerosis — Obstruction  of  the  Central 
Artery — Tlirombosis  of  the  Central  Artery — Thrombosis  of  the 
Retinal  Vein — Quinine  Amaurosis — Amaurosis  from  Filix  Mas      323 

Atrophies,      or     Degenerations  —  Retinitis     Pigmentosa  —  Retinitis 

Punctata  Albescens — Gyrate  Atrophy     .  .  .  .  .328 

Injury  of  the  Retina  by  Strong  Light — Direct  Sunlight — Snow- 
Blindness — Electric   Light      .  .  .  .  .  .  .331 

Tumours  of  the  Retina — Glioma — Tubercle  .....       334 

Parasitic  Disease  of  the  Retina — Cysticercus  .  .  .  .  .335 

Detachment  of  the  Retina   .  .  .  .  .  .  .  .336 

Traumatic  Affections  of  the  Retina — Ana?sthesia — Commotio  Re- 
tinae— '  Holes  '  at  the  Macula  Lutea         .....      339 


CHAPTER   XIII. 

DISEASES    OF   THE    OPTIC   NERVE. 

Optic  Neuritis  (Papillitis),  due  to  :    Cerebral  Tumours — Tubercular 
Meningitis — Hydrocephalus — Tumours    of    the    Orbit — Inflam- 
matory Processes  in  the  Orbit — Exposure  to  Cold — Suppression 
of    Menstruation  —  Chlorosis  —  Syphilis  —  Rheumatism  —  Lead- 
Poisoning — Peripheral  Neuritis — Disseminated  Sclerosis — Tabes 
Dorsalis — Hereditary  Predisposition — Certain  Fevers        .  .341 

Retro-Bulbar  Optic  Neuritis — Optic  Neuritis  Associated  with  Per- 
sistent Cerebro- Spinal  Rhinorrhoea  .  .  .  .  .347 

Toxic  Amblyopia  (Axial  Neuritis)  ......       349 

Atrophy  of  the  Optic  Nerve,  due  to  :    Optic  Neuritis — Pressure — 
Embolism  of  the  Central  Artery — Syphilitic  Retinitis — Retinitis 
Pigmentosa — Chorioido-Retinitis    ......       353 

Primary  Atrophy,  due  to  :    Hereditary  Predisposition,  with  Disease 
of  the  Spinal  Cord,  as  a  Purely  Local  Disease,  from  Poisoning 
with  Organic  Preparations  of  Arsenic      .....      354 

Tumours  of  the  Optic  Nerve — Hyaline  Outgrowths  .  .  .      357 

Injuries  of  the  Optic  Nerve  .......      357 

Amblyopia  due  to  Haemorrhages  from  the  Stomach,  Bowels,  or  Uterus 

— Glycosuric  Amblyopia         .......       357 


CONTENTS 


CHAPTER    XIV. 

PART    I. 

pa(;e 

OCULAR  DISEASES  AND  SYMPTOMS  LIABLE  TO  ACCOMPANY  FOCAL 
DISEASE  OF  THE  BRAIN. 

Hemianopsia — Arrangement  of  the  Cortical  Visual  Centres,  their 
Relations  to  the  Retina,  and  the  Course  of  the  Optic  Fibres 
between  these  Two  Points — Localisation  of  the  Lesion  in 
Hemianopsia — Word -Blindness  —  Visual  Aphasia  —  Dyslexia  — 
Amnesic  Colour-Blindness  —  Visual  Hallucinations  —  Mind- 
Blindness,  or  Optic  Amnesia  ......      3G0 


PART   II. 

OCULAR    DISEASES  AND    SYMPTOMS    LIABLE  TO    ACCOMPANY    CERTAIN 

DIFFUSE    ORGANIC    DISEASES    OF   THE    BRAIN. 

Disseminated  Sclerosis  of  the  Brain  and  Spinal  Cord — Diffuse 
Sclerosis  of  the  Brain — General  Paralysis  of  the  Insane — Am- 
aurotic Family  Idiocy — Maculo-cerebral  Degeneration — Menin- 
gitis— Traumatic  Meningitis — Hydrocephalus — Infantile  Para- 
lysis— Paralysis  Agitans — Epilepsy — Chorea     .  .  .  ,372 


FART  III. 

OCULAR   DISEASES    AND    SYMPTOMS    LIABLE   TO    ACCOMPANY   CERTAIN 
DISEASES    AND    INJURIES    OF   THE    SPINAL    CORD. 

Tabes  Dorsalis — Hereditary  Ataxy — Myelitis — Syringomyelia — Myo  - 
tonia  Congenita — Acute  Ascending  Paralysis — Injuries  of  the 
Spinal  Cord 379 

PART    IV. 

NERVOUS  AMBLYOPIA,  OR  NERVOUS  ASTHENOPIA. 

Nervous     Amblyopia     in     Neurasthenia — Nervous     Amblyopia     in 

Hysteria — Nervous  Amblyopia  in  Traumatic  Neurosis     .  .      383 


PART    V. 

VARIOUS    FORMS    OF   AMBLYOPIA. 

Transitory  Hemianopsia,  or  Scintillating  Scotoma  —  Congenital 
Amblyopia — Amblyopia  during  Pregnancy — Reflex  Amblyopia 
— Night-Blindness — Ura3mic  Amblyopia — Pretended  Amaurosis 
— Erythropsia 390 


CONTENTS 


CHAPTER    XV. 

ELEMENTARY    OPTICS. 


PAGE 


Divergence  and  Parallelism  of  Rays  of  Light — Refraction — Index 
of  Refraction  —  Plane  Glass  —  Prisms  —  Spherical  Lenses  — 
Optical  Defects  of  Lenses — Sphero-Cylindrical  and  Toric 
Lenses — Cylindrical  Lenses — Numbering  and  Decentration  of 
Lenses — Protective  Glasses    .......       396 


CHAPTER    XVI. 

ABNORMAL   REFRACTION   AND    ACCOMMODATION. 

Ametropia — Myopia — Definition      and      Causes      of      M, — Punctum 
Remotum    in    M. — Optical    Correction    of    M. — Diagnosis    and 
Determination    of    Degree    of    M. — Amplitude    and    Range    of 
Accommodation  in  M. — Angle  Gamma  in  M. — Etiology  of  M. — 
Non-Progressive  M. — Symptoms  of  M. — Complications  of  Pro- 
gressive  M. — Pernicious   M. — Functional   Anomalies   attendant 
upon  Progressive  M. — Management  of  ]\I. — The  Prescribing  of 
Spectacles  in  M. — Operative  Cure  of  M.   .  .  .  .  .414 

Hypermetropia — -Definition,  and  Optical  Causes  of  H. — Punctum 
Remotum  in  H. — Optical  Correction  of  H. — Determination  of 
Degree  of  H. — Amplitude  and  Range  of  Accommodation  in 
H. — Angle  Gamma  in  H. — Varieties  of  H.  in  relation  to  Accom- 
modation— Etiology  of  H. — Symptoms  of  H. — Accommodative 
Asthenopia  in  H. — Internal  Strabismus  in  H. — The  Prescribing 

of  Spectacles  in  H 428 

Astigmatism — Varieties  of  As. — Symptoms  of  Regular  As. — Estima- 
tion of  Degree  of,  and  Correction  of  As. — The  Astigmometer — 
Lental  As. — Irregular  As.       .......      436 

Anisometropia    .  .  .  .  .  .  .  .  .  .447 

Estimation  of  the  Refraction  by  Aid  of  the  Ophthalmoscope  .  .447 

Retinoscopy         .  .  ...  .  .  .  .  .  .       452 

Anomalies  of  Accommodation — Presbyopia — Paralysis  of  Accom- 
modation— Accommodative  Asthenopia — Spasm  of  Accommo- 
dation ..........      460 


CHAPTER    XVII. 

THE    ORBITAL    MUSCLES    AND    THEIR    DERANGEMENTS. 

Normal  Action  of  the  Orbital  Muscles — Inclination  of  the  Vertical 
Meridian  in  the  Several  Principal  Positions — ]\Iuscles  called 
into  Action  in  the  Several  Principal  Positions — Subjective  and 
Objective  Localisation — The  Field  of  Fixation  .  .  .      466 


CONTENTS 


Strabismus  —  Latent    Strabismus,    or    Heterophoria  —  Binocular 

Vision  and  Sense  of  Fusion — Diplopia     .....      472 

Paralyses  of  the  Orbital  Muscles — General  Symptoms — Paralysis 
of  the  External  Rectus  —  Paralysis  of  the  Superior  O  liquc  — 
Paralysis  of  the  Internal  Rectus,  Superior  Rectus,  Inferior 
Oblique,  and  Levator  Palpebrse — Mnemonic  Diagrams — Mea- 
surement of  the  Degree  of  Paralysis — Causes  of  Paralysis  of 
Orbital  Muscles — Ophthalmoplegic  Migraine — Ophthalmoplegia 
Externa,  or  Nuclear  Paralysis — Fascicular  Paralyses — Myas- 
thenia Gravis — Cerebral  Paralysis  of  Orbital  Muscles — The 
Localising  Value  of  Paralyses  of  Orbital  Muscles  in  Cerebral 
Disease — Congenital  Defects  of  Motion  .....      476 

Convergent  Concomitant  Strabismus — Causes — Single  Vision  in — 
Amblyopia  of  Squinting  Eye — Clinical  Varieties  of — Measure- 
ment of — Mobility  of  Eye  in — Treatment — Optical  Treat- 
ment— Orthoptic  Treatment — Operative  Treatment — Tenotomy 
— Advancement  of  External  Rectus — Dangers  of  the  Strabismus 
Operation — Treatment  subsequent  to   Operation      .  .  ,      506 

Divergent  Concomitant  Strabismus        .  .  .  .  .  .525 

Latent  Deviations  (Heterophoria) — Tests  for  Latent  Deviations — 
Symptoms  —  Treatment  —  Latent  Torsion  —  Insufficiency  of 
Convergence — Spasm  of  the  Orbital  Muscles — The  Diplcscope 
— Harman's   Test 526 

Nystagmus — Amblyopic  Nystagmus — Coal  Miner's  Nystagmus— 
Vestibular  Nystagmus — Nystagmus  in  Diseases  of  Nervous 
System 536 


CHAPTER    XVIII. 

DISEASES    OF   THE    EYELIDS. 

Eczema — (Edema — Marginal  Blepharitis  (Ophthalmia  Tarsi) — Phthei- 
riasis  Ciliorum — Hordeolum  (Stye) — Chalazion  (Meibomian  Cyst, 
Tarsal  Tumour) — Milium — MoUuscum — Nnpvus — Xanthelasma 
—  Chromidrosis  —  Herpes  Zoster  Ophthalmicus  —  Syphilitic 
Affections — Vaccine  Vesicles — Rodent  Ulcer — Solid  CEdema, 
or  Elephantiasis  Lymphangioides  —  Plexiform  Neuroma  — 
Lymphoma — Epithelioma,  Sarcoma,  Adenoma,  and  Lupus — 
Gangrene — Clonic  Cramp  of  the  Orbicularis  Muscle — Blepharo- 
spasm— Ptosis — Operations  for  its  Cure — Lagophthalmos — 
Symblepharon — Blepharophimosis — Canthoplastic  Operation — 
Distichiasis  and  Trichiasis  —  Operations  for  their  Cure — 
Entropion,  Spastic  Entropion,  Senile  Entropion,  Opera- 
tions for  its  Cure — Ectropion — Operations  for  its  Cure — Ihe 
Restoration  of  an  Eyelid — Ankyloblepharon — Injuries — Epican- 
thus— Congenital  Coloboma  .  .  .  .  .  •  .541 


CONTENTS 


CHAPTER    XIX. 

DISEASES    OF    THE    LACRIMAL    APPARATUS. 

PA(.R 

ivfalposition  of  the  Punctum  Lacrimale — Stenosis,  and  Occlusion 
of  the  Punctum  Lacrimale  —  Obstruction  of  the  CanaHcuhis  — 
Stricture  of  the  Nasal  Duct — Blennorrhcea  of  the  Lacrimal 
Sac — Extirpation  of  the  Lacrimal  Sac — Acute  Dacryocystitis — 
Dacryoadenitis — Tumours  of  the  Lacrimal  Gland — Cysts  of  the 
Lacrimal  Gland — Symmetrical  Chronic  Swelling  of  the  Lacrimal 
and  Salivary  Glands — Extirpation  of  the  Lacrimal  Gland  .  ,      Mi) 

CHAPTER    XX. 

DISEASES    OF   THE    ORBIT. 

Exophthalmos — Orbital  Cellulitis — Tenonitis — Periostitis  of  the 
Orbit — Caries  of  the  Orbit — ^Injuries  of  the  Orbit — Enophthalmos 
— Orbital  Tumours — Hernia  Cerebri — Cysts — Solid  Tumours 
— Symmetrical  Tumours — Pulsating  Exophthalmos — Intermit- 
tent Exophthalmos — Tumours  of  the  Optic  Nerve — Implication 
of  Neighbouring  Cavities — Shrinking  of  the  Conjunctiva- 
Temporary  Resection  of  the  Outer  Wall  of  the  Orbit — Exoph- 
thalmic Goitre       .........      590 


APPENDIX 

Regulations  as  to  Defects  of  Vision  which  Discjualify  Candidates 
for  Admission  into  the  Civil,  Naval,  and  Military  Government 
Services,  the  Royal  Irish  Constabulary,  and  the  Mercantile 
Marine 625 


Index        .  .  .  .  .  .  .  .  .  .  .63' 


TO    THE    STUDENT. 

The  student  may  at  first  omit  the  portions  printed  in  small  type, 
and  those  marked  with  an  asterisk,  including  the  whole  of  chapter 
xiv.  With  these  exceptions  he  should  carefully  read  chapters 
i.,  ii.,  XV.,  and  xvi.,  immediately  on  joining  the  ophthalmic  hospital 
or  department. 


xvm 


DISEASES  OF  THE   EYE 


CHAPTER    I. 

Preliminary    Note    on    the    Clinical    Examination    of     Eye 

Patients. 

In  general  medicine  and  surgery,  the  importance  of  systematic 
clinical  methods  is  well  recognised.  System  is  even  more  necessary 
in  the  clinical  study  of  diseases  of  the  eye,  where  the  changes  from 
the  normal  are  often  so  minute  that  they  may  readily  escape 
observation,  and  the  symptoms  depending  on  derangement  of  the 
functions  of  the  organ  are  sometimes  such,  that  the  patient  may 
himself  be  unaware  of  them. 

Before  examining  the  eye,  a  general  observation  of  the  patient 
should  be  made,  whereby  suggestive  hints  are  often  obtained  for 
diagnosis.  For  example  :  the  manner  m  which  a  patient  enters 
a  room  may  help  to  distinguish  between  an  affection  of  the  nervous 
apparatus  of  the  eye  and  cataract,  or  his  gait  may  suggest  an  affec- 
tion associated  with  disease  of  the  spinal  cord.  Again,  a  strumous 
appearance,  enlarged  glands,  eczema,  syphilitic  eruptions,  or  the 
aspect  due  to  hereditary  syphilis  afford  information  not  to  be 
disregarded. 

There  are  many  obvious  local  conditions,  which  are  liable  to 
escape  the  attention  of  a  beginner  who  is,  as  so  many  are  inclined 
to  be,  too  hasty  in  his  desire  to  make  a  close  inspection  of  the 
eyeball  itself ;  for  example,  the  presence  of  slight  strabismus, 
photophobia,  slight  ptosis,  or  the  sleepy  appearance  due  to  the 
heavy  thickened  lid  in  granular  ophthalmia.  We  mention  these 
merely  to  indicate  the  advantages  which  may  be  gained  by  quietly 
taking  a  general  view  of  the  patient,  and  of  his  eyes,  at  a  little 
distance,  before  proceeding  to  examine  the  latter  more  closely. 

The  examination  of  the  eye  may  be  divided  into  three  parts, 
1 


DISEASES    OF    THE    EYE.  [chap.  t. 


which  are  usually  taken  in  the  following  order :  1.  Objective 
examination  in  daylight.  2.  Subjective,  or  functional,  examina- 
tion. 3.  Objective  examination  in  the  dark  room.  All  these  will 
be  described  in  their  appropriate  places  in  the  following  pages,  and  it 
is  only  necessary  here  to  mention  some  of  their  subdivisions.  Under 
the  first  will  come  inspection  (and  palpation  when  possible)  of 
the  orbit,  eyelids,  lacrimal  passages,  conjunctiva,  cornea,  anterior 
chamber,  iris  (its  colour  and  structure,  and  the  mobility,  shape, 
and  size  of  the  pupil),  anterior  layers  of  the  lens  in  the  pupillary 
area,  and  testing  the  intra-ocular  tension.  The  second  will  include 
tests  for  acuteness  of  vision,  field  of  vision,  accommodation,  binocular 
vision,  orbital  muscles,  colour-vision,  and  light-sense.  Finally,  in 
the  dark  room  the  anterior  parts  of  the  eye,  including  the  lens, 
and  sometimes  the  anterior  portion  of  the  vitreous  humour,  are 
first  examined  by  reflected  light,  with  oblique  illumination,  and  then 
with  a  strong  -\-  lens  in  the  ophthalmoscope.  The  details  of  the 
fundus  are  then  observed  with  the  ophthalmoscope,  and  the  refrac- 
tion is  estimated  if  necessary.  One  should  never  omit  to  compare 
the  affected  eye  with  its  fellow,  if  only  one  eye  be  diseased. 

It  is  not  intended  that  all  these  methods  of  examination  should 
be  put  into  use,  or  considered  even  necessary,  in  every  case  ;  but 
they  should  be  borne  in  mind,  if  nothing  is  to  escape  attention. 


OPTICAL    STRUCTURE   AND   FUNCTIONAL  EXAMINATION 
OF   THE   EYE. 

Optical  Structure  of  the  Eye. — The  eye  is  a  dark  chamber 
lined  by  the  uveal  pigment,  which  prevents  the  rays  of  light  from 
entering  the  eye,  except  through  the  transparent  media  and  pupil. 
It  possesses  three  refracting  or  dioptric  ^  media,  limited  by  three 
convex  surfaces.  The  dioptric  media  are  the  aqueous  humour, 
the  substance  of  the  crystalline  lens,  and  the  vitreous  humour. 
The  convex  surfaces  are  the  anterior  surface  of  the  cornea,^  and 
the  anterior  and  posterior  surfaces  of  the  crystalline  lens. 

1  The  phenomena  of  refraction  are  sometimes  referred  to  as  Dioptrics, 
and  those  of  reflection  as  Catoptrics. 

2  The  posterior  surface  of  the  cornea  may  be  neglected,  since  it  is 
parallel  to  the  anterior  surface,  and  the  index  of  refraction  of  the  cornea 
is  the  same  as  that  of  the  aqueous  humour. 


CHAP.  I.]         OPTICAL    STRUGTVUE    OF    THE    EYE.  3 

By  aid  of  this  apparatus,  which  is  called  the  Dioptric  System  of 
the  eye,  distinct  inverted  images  of  external  objects  are  formed  on 
the  retina,  in  the  same  way  as  images  are  formed  by  a  convex  lens 
(see  §  22,  chap.  xv.). 

The  refracting  surfaces,  which  are  practically  spherical,  are 
centred  on  the  Optic  Axis  (0  P,  Fig.  1),  an  imaginary  line  which, 
passing  through  the  optical  centre  (N)  of  the  eye,  meets  the  retina 
at  a  point  (P),  the  posterior  principal  focus  (§  15,  chap,  xv.), 
slightly  to  the  inner  side  of  the  macula  lutea  (M). 

The  optic  axis  of  the  eye 
is  similar  to  the  principal 
axis  of  a  convex  lens  (see  § 
14,  chap.  XV.).  The  optical 
centre  N,  which  is  called  the 
Nodal  Point,  is  situated  just 
in  front  of  the  posterior 
surface  of  the  lens,  and  rays  Fig.  1.— 0  P,  Optic  axis ;  FM,  Vis^ 

passing  through  it  are  not  "^^^^."^'  ^/  F  angle  y;  ^.centre  of 
T      .    ,     T.      ,T    .  ,1     1     .  rotation  ;  iV,  nodal  point ,  C,  centre  of 

deviated  m  their  path,  being       cornea 

in  fact  secondary  axes  (§  14, 

chap.  XV.).  F  M  is  the  Visual  Line,  which  unites  the  object 
looked  at  (called  the  point  of  fixation)  with  the  macula  lutea 
(M)  and  passes  through  the  nodal  point. 

The  Line  of  Fixation  {R  V)  joins  the  centre  of  rotation  (7?)  of 
the  eye  with  the  point  of  fixation.  The  angle  0  R  V  formed  at  the 
centre  of  rotation,  by  the  optic  axis  and  the  line  of  fixation,  is 
called  the  angle  y.^ 

The  line  of  fixation  and  the  visual  line  so  nearly  coincide  that 
in  practice  we  regard  them  as  identical ;  and  hence  the  angle  y 
is  practically  the  same  as  0  iV  F. 

The  angle  k  is  the  angle  between  the  fixation  line  and  a  per- 
pendicular line  through  the  cornea,  opposite  the  centre  of  the 
pupil.      In  practice  it  is  the  angle  k  which  is  measured.      It  is  not 

1  Some  writers  call  this  angle  a  (alpha).  But  the  angle  a  originally- 
meant  the  angle  between  the  visual  line  and  the  major  axis  of  the  corneal 
ellipse,  and  was  founded  on  the  view  that  the  cornea  was  an  ellipsoid — 
a  view  which  has  been  shown  to  be  erroneous  by  Tscherning  and  others. 
Indeed,  the  "  working  area,"  or  optical  portion  of  the  cornea,  which 
includes  13°  to  16°,  is  approximately  spherical. 


DISEASES    OF    THE    EYE. 


.[chap.  1. 


equal  to  the  angle  y,  because  the  centre  of  the  pupil  is  a  little  to 
the  inner  side  of  the  centre  of  the  cornea. 

In  order  to  measure  the  angle  k,  the  eye  is  placed  at  the  peri- 
meter (p.  17)  as  for  an  examination  of  its  field  of  vision,  that  is 
to  say,  looking  at  the  zero  point.  A  candle  flame  is  then  moved 
along  the  arc  of  the  perimeter,  until  the  corneal  image  of  the  light 
appears  to  the  observer  (whose  eye  is  in  a  line  with  the  candle  and 
its  image)  to  be  in  the  centre  of  the  pupil.  The  number  on  the  arc 
of  the  perimeter  opposite  the  candle  gives  the  value  of  the  angle  k, 
the  average  size  of  which  is  5°. 

Refraction. 

By  the  Refraction  of  the  Eye  is  meant,  in  a  general  sense,  the 
faculty  it  has  when  at  rest  (i.e.,  without  an  effort  of  accommoda- 


FiG.   2. 

tion)  of  altering  the  direction  of  rays  of  light  which  pass  into  it, 
making  parallel  rays  convergent,  and  divergent  rays  less  divergent. 
But,  as  usually  understood,  it  means  the  relation  which  the  position 
of  the  retina  bears  to  the  principal  focus  of  the  dioptric  system. 

In  Normal  Refraction,  or  Emmetropia  (e/xyaerpoi/,  the  standard  ; 
o>i//,  the  eye),  as  it  is  termed,  the  retina  lies  at  the  posterior  principal 
focus  (Fig.  2),  and  therefore  parallel  rays  are  brought  to  a  focus 
on  the  layer  of  rods  and  cones  of  the  retina,  and  form  on  it  a  dis- 
tinct inverted  image  of  the  point  or  object  from  which  they  come. 
The  emmetropic  eye,  in  a  state  of  rest,  is  thus  adapted  for  seeing 
distant  objects,  and  its  far  point  (punctum  remotum)  is  at  infinity. 
Conversely,  if  the  retina  be  illuminated,  the  rays  proceeding  from 
any  point  on  it  will  emerge  from  the  eye  parallel.  In  the  normal 
eye  the  posterior  focal  length  of  the  dioptric  system  is  23   mm. 


OPTICAL    STRUCTURE    OF    THE    EYE. 


and  the  average  length  of  the  eyeball  including  the  sclerotic  is 
24  mm. 

Accommodation. 

The  eye  can  see  near  objects  distinctly  as  well  as  distant  objects, 
although  the  rays  from  any  given  point  (a,  Fig.  3)  of  a  near  object 
reach  the  eye  with  a  divergence  so  considerable,  that  they  could 
not  be  brought  to  a  focus  on  the  retina  by  the  unaided  refrac- 
tion, but  would  converge  towards  a  point  their  conjugate  focus 
a'  (§16,  chap,  xv.),  namely  behind  the  retina,  and  would  not  form 
a  distinct  image  on  the  latter,  but  merely  a  blurred  image  or  circle 
of  diffusion  (at  h  c).  It  is  obvious,  therefore,  that  an  increase  of 
refracting  power  in  the  eye  is  necessary,  in  order  that  near  objects 


riG.^3. 

may  be  distinctly  seen.  It  is  this  increase  in  the  refracting  power 
for  the  purpose  of  near  vision  which  is  called  Accommodation. 

The  Mechanism  of  Accommodation  is  as  follows  : — The  ciliary 
muscle  (m.  Fig.  4)  contracts,  thus  drawing  forward  the  chorioid 
and  the  ciliary  processes,  and  relaxing  the  zonula  of  Zinn  {z),  which 
is  attached  to  the  latter.  The  lens  {I),  which  was  flattened  by  the 
tension  of  the  zonula,  is  now  free  to  assume  a  more  spherical  shape, 
in  response  to  its  own  elasticity.  The  posterior  surface  of  the 
lens  scarcely  alters  in  shape,  being  fixed  in  the  patellary  fossa  ; 
but  the  anterior  surface  becomes  more  convex,  thus  increasing  its 
refracting  power.  Associated  with  the  act  of  accommodation  is 
a  contraction  of  the  pupil.  The  accompanying  figure  (Fig.  4) 
represents  the  changes  which  take  place  in  accommodation,  the 
dotted  lines  indicating  the  latter  state. 

Tscherning  has  shown  that  the  increased  curvature  of  the 
anterior  surface  of  the  lens  occurs  mainly  in  the  centre  of  that 
surface — in  other  words,  that  in  accommodation  the  anterior  surface 
becomes  somewhat  conical,  and  not  merely  more  spherical, 


6  DISEASES    OF    THE    EYE.  [chap.  i. 

During  accommodation,  owing  to  relaxation  of  the  suspensory 
ligament,  the  lens  sinks  down  a  little,  and  becomes  tremulous  on 
movement  of  tlie  eye,  and  there  is  no  increase  in  the  intra-ocular 
tension. 

Accommodation  is  always  associated  with  contraction  of  the 
pupil  and  convergence  of  the  optic  axes. 

The  Far  Point  and  the  Near  Point.— It  is  possible  for  the  eye, 


Fig.  4. — c,  cornea  ;    a,  anterior  chamber  ;    I,  lens  ;    v,  vitreous  humour  ; 
i,  iris  ;    z,  zonula  of  Zinn  ;    m,  ciliary  muscle. 

by  changing  the  accommodation,  to  see  objects  accurately  at  every 
distance  from  its  Far  Point — i.e.,  its  most  distant  point  of  dis- 
tinct vision  (Punctum  Remotum, — R.),  up  to  a  point  only  a  few 
centimetres  from  the  eye,  called  the  Near  Point  (Punctum  Proxi- 
mum, — P.).  We  can  find  the  latter  by  directing  the  patient  to 
look  at  a  page  printed  in  small  type,  and  by  bringing  it  slowly 
closer  and  closer  to  his  eye,  until  a  point  is  reached  where  he  cannot 
distinguish  the  words  and  letters,  which  become  blurred.  A  point 
very  slightly  more  removed  from  the  eye  than  this,  where  he  can 
read  distinctly,  is  the  near  point.  Between  the  near  point  and 
the  eye  vision  is  indistinct,  because  no  effort  of  the  ciliary  muscle 
can  produce  the  amount  of  convexity  of  the  lens  required  for  so 
short  a  distance. 

The  Amplitude  and  Range  of  Accommodation. — This  is 
the  amount  of  accommodative  effort  of  which  the  eye  is  capable 
— i.e.,  the  effort  it  makes  in  order  to  adapt  itself  from  its  Far  Point 
(R.)  up  to  its  Near  Point  (P.).     The  amplitude  of  accommodation 


CHAP.  I.]  FUNCTIONAL  EXAMINATION  OF  THE  EYE.  7 

{a),  therefore,  is  equal  to  the  difference  between  the  refracting 
power  of  the  eye  when  its  accommodation  is  exerted  to  the  utmost 
(p),  and  when  at  rest  (/•),  as  expressed  by  the  formula  a  =  f  —  r. 
It  may  be  represented  by  that  convex  lens  placed  close  in  front 
of  the  eye,  which  would  take  the  place  of  the  increased  convexity 
of  the  lens,  or,  in  other  words,  which  would  give  to  rays  coming 
from  the  nearest  point  of  distinct  vision  a  direction  as  if  they  came 
from  the  far  point.  The  number  of  this  lens  expresses  the  ampli- 
tude of  accommodation  in  a  given  eye. 


Fig.   5. 

For  example  :  if,  in  an  emmetropic  eye  {E,  Fig.  5)  the  near 
point  be  situated  at  20  cm.,  then  a  convex  lens  (L)  of  20  cm.  focal 
length  placed  close  to  the  eye  (between  that  point  and  the  eye) 
would  give  to  rays  coming  from  the  near  point  a  direction  as  though 
they  came  from  a  distant  object  {i.e.,  would  make  them  parallel), 
and  this  normally  refracting  eye  would  then  be  enabled,  by  aid  of 
its  refraction  alone,  to  bring  these  rays  to  a  focus  on  the  retina. 
Making  use  of  the  above  equation,  we  find  in  this  case — since  a  focal 
length  of  20  cm.  represents  a  lens  of  5  D — that  p  =  5  and  therefore 
a  =  5  —  r,  but  R  being  situated  at  infinity  (designated  by  the  sign  oo) , 

r  =  i  =  i   =  0  ;   therefore  a  =  5  —  0  =  5  D.i 
K         00 


^  It  must  be  observed  that  R  represents  the  distance  of  the  Far  Point 
from  the  eye,  while  r  represents  the  refractive  power  which  is  added  to 
the  eye  by  accominodation,  or  by  a  lens,  in  order  to  adapt  it  for  the  dis- 
tance R.  Hence  it   is  evident    that  r  =  ^,  because   the  strength,  or  re- 

R 

fractive  power,  of  a  lens  is  inversely  as  its  focal  length — e.g.,  a  lens  of 

the  strength  of  4  D  will  have  a  focal  length  of  ^  that  of  a  lens  of  1  D — 

1  m.      100  cm.     „_  /        ooo     1  \       o-      1     1  1        1  1 

I.e.,  — — —  = =25  cm.  (see  §  28,  ch.  xv.).      similarly,  p  =  ^  and  a  =  .' 

P  representing  the  distance  of  the  Near  Point,  and  A  the  focal  length  of 
the  lens  a  which  represents  the  Amplitude  of  Accomniodation. 


DISEASES    OF    THE    EYE. 


[CHAP.    I. 


Fig.  6. — Eye  accommodated  for  0 
which  forms  a  distinct  image  on  the 
retina,  R.  Parallel  rays  now  unite  in 
front  of  the  retina  at  a  shorter  distance,  F. 


The  amplitude  of  accommodation  {i.e.,  the  number  of  the  lens 
which  would  represent  it)  is  the  same  in  every  kind  of  refraction, 
according  to  the  age  of  the  individual,  but  in  emmetropia  alone  is 
a  =  J)  a,s  above,  because  in  it  alone  is  r  =  0. 

It  is  evident  that,  as  the  refractive  power  of  the  eye  is  increased 

during  accommodation,  the 
eye  is  rendered  temporarily 
myopic  as  regards  parallel 
rays  (Fig.  6). 

Under     the     head     of 
"  Anomalies  of  Accommo- 
dation," chap,  xvi.,  will  be 
found    Bonders'     diagram 
representing  the  amplitude 
of  accommodation  at    dif- 
ferent ages. 
The  Range  of  Accommodation  is  the  distance  between  the  far 
point,  R,  and  the  near  point,  P.     As  will  be  seen  later  on,  it  is  not 
always  the  same  for  a  given  amplitude. 

Connection  between  Accommodation  and  Convergence  (Relative  Accommo- 
dation).— By  convergence  we  mean  the  inward  rotation  of  the  eyes 
which  is  necessary  in  looking  at  a  near  object,  in  order  to  obtain  single 
vision  with  both  eyes.  With  each  degree  of  convergence  of  tlie  visual  lines 
a  certain  effort  of  accommodation  is  associated.  Thus,  if  the  object  be 
situated  2  metres  from  the  eye,  the  visual  lines  converge  to  that  point, 
and  a  certain  effort  of  accommodation  (0*5  D)  is  made.  But  this  connection 
between  accommodation  and  convergence  is  somewhat  elastic,  for  the 
accommodative  effort  may  be  increased  or  decreased,  while  the  object  is 
kept  distinctly  in  view,  and  the  same  convergence  maintained.  That  it 
may  be  increased  is  shown  by  the  experiment  of  placing  a  weak  concave 
glass  before  the  eye,  when  it  will  be  found  that  the  object  is  still  distinctly 
seen  ;  or  if  a  weak  convex  glass  be  held  before  the  eye  the  object  will  also 
be  clearly  seen,  showing  that  the  accommodative  effort  may  be  lessened 
without  affecting  vision  or  convergence.  This  amplitude  of  accommoda- 
tion for  a  given  point  of  convergence  of  the  visual  lines,  found  by  the 
strongest  concave  and  strongest  convex  glasses  with  which  the  object 
can  still  be  distinctly  seen,  is  called  the  Relative  Amplitude  of  Accommo- 
dation. That  part  of  it  which  is  already  in  use,  and  is  represented  by  the 
convex  lens,  is  termed  the  negative  part ;  while  the  positive  part  is  repre- 
sented by  the  concave  lens,  and  has  not  been  brought  into  play.  For 
sustained  accommodation  at  any  distance,  it  is  necessary  that  the  positive 
part  of  the  relative  amplitude  of  accommodation  be  considerable  in  amount. 

Moreover,  the  convergence  may  be  altered,  while  the  same  effort  of 
accommodation  is  maintained,  as  is  shown  by  the  experiment  of  placing  a 


CHAP.  I.]      FUNCTIONAL  EXAMINATION  OF  THE  EYE. 


9 


weak  prism  with  its  base  inwards  before  one  eye.  In  order  that  the  object 
may  then  be  seen  singly,  it  will  be  necessary  for  the  eye  before  which  the 
prism  is  placed  to  rotate  somewhat  outwards  ;  and  it  will  be  found  that 
the  individual  can  do  this,  while  at  the  same  time  he  sees  the  object  with 
the  same  distinctness,  showing  that  the  same  effort  -of  accommodation 
has  been  maintained,  although  the  angle  of  convergence  of  the  visual  axis 
is  less  than  before. 


Convergence. 


*  Range  and  Amplitude  of  Convergence. — The  nearest  point 
for  which  the  eye  can  converge  and  still 
see  single  is  the  Near  Point  of  convergence. 
The  Far  Point  of  Convergence  is  the  point 
at  which  the  visual  lines  meet  when  the  eyes 
are  at  rest ;  as  the  position  of  rest  is  one 
of  slight  divergence,  this  imaginary  point 
usually  lies  behind  the  head,  and  the  devia- 
tion from  parallelism  to  this  degree  of  diver- 
gence is  known  as  negative  convergence. 
The  Amplitude  of  Convergence  is  the  sum  of 
the  positive  and  negative  convergence.  The 
Range  of  Convergence  is  the  distance  be- 
tween the  far  and  near  points  of  convergence. 

The  near  point  of  convergence  is  found 
by  bringing  an  object,  such  as  a  fine  line, 
up  to  the  eyes  in  the  middle  line,  until  it 
begins  to  be  seen  double.  The  far  point  of 
convergence,  or  rather  the  negative  con- 
vergence, can  be  measured  by  prisms  placed 
base  inwards  while  the  patient  looks  at  a 
distant  object.  In  some  cases  the  eyes  are 
parallel  or  slightly  convergent  when  at  rest,  and  then  convergence 
is  altogether  positive. 


Fig.   7. 


The  Unit  of  Convergence.     The  Metre  Angle. 

If  the  visual  line  {E  1,  Fig.  7)  of  an  eye  {E)  be  brought  to  bear  on 
a  point  (1,  Fig.  7)  1  metre  distant  from  it  in  the  median  line  {M  1),  the 
angle  of  convergence  {E  1  M  =  I  E  D)  which  the  visual  line  thus  makes 
with  the  median  line  is  called  the  Metre  Angle.      It  expresses  the  degree 


10  DISEASES    OF    THE    EYE.  [chap.  i. 


of  convergence  necessary  for  binocular  vision  at  that  distance,  and  is 
employed  as  the  unit  for  expressing  other  degrees  of  convergence.  If, 
for  example,  an  object  be  situated  ^  a  metro  (^,  Fig.  7)  from  the  eye,  the 
angle  of  convergence  {E  |  M)  must  be  practically  twice  as  large  as  at 
1  metre  :  C.  (Convergence)  =  2  metre  angles.  If  the  object  be  only  |  of  a 
metre  distant,  3  metre  angles  are  required  :  C.  =3  metre  angles.  If  the 
object  be  situated  2  metres  from  the  eye,  the  angle  of  convergence  will 
only  be  one-half  as  great  as  that  at  1  metre,  and  here  C.  =  ^  metre  angle  ; 
while  if  the  eye  be  directed  towards  a  distant  object  (D)  there  will  be  no 
angle  of  convergence,  and  if  the  visual  lines  be  divergent  the  metre  angle 
will  be  negative. 

Now  the  emmetropic  eye  normally  requires  for  each  distance  of  bino- 
cular vision  as  many  metre  angles  of  convergence  as  it  requires  dioptrics 
of  accommodation.  For  a  distance  of  1  metre  an  effort  of  accommodation 
of  1  dioptre  is  required,  and  also  1  metre  angle  of  convergence  ;  at  \  metre 
from  the  eye  2  D  of  accommodation  is  required  and  2  metre  angles  ;  at 
^  metre  from  the  eye  3  D  of  accommodation  and  3  metre  angles,  and  so 
on  ;  while  for  distant  objects  neither  convergence  nor  accommodation 
is  reqviired.  The  positive  portion  of  the  average  normal  convergence  is 
about  10  metre  angles  and  the  negative  1  metre  angle. 

Binocular  Vision  will  be  described  in  chap.  xvii. 


THE    SENSE   OF   SIGHT. 

The  Sense  of  Sight  consists  of  three  Visual  Perceptions  or  Sub- 
Senses — namely,  the  Light-Sense,  the  Colour-Sense,  and  the  Form- 
Sense. 

The  Light- Sense  is  the  power  the  retina,  or  the  visual  centre,  has  of 
perceiving  gradations  in  the  intensity  of  illumination.  The  light-sense 
can  be  tested  by  Forster's,  or  by  Izard  and  Chibret's  photometer.  On 
looking  through  the  latter  towards  the  sky  two  equally  bright  discs  are 
seen.  By  a  simple  mechanism  one  of  the  discs  can  be  made  darker.  If 
the  eye  does  not  perceive  the  difference  in  illumination  between  the  two 
discs  within  5°  its  light-sense  is  abnormal,  or  we  may  say  its  L.D.  (Light 
Difference)  is  too  high.  Again,  if  one  disc  be  made  quite  dark,  and  be 
then  gradually  lighted,  the  patient  is  required  to  indicate  the  smallest 
degree  of  light,  or  L.M.  (Light  Minimum),  by  which  he  can  observe  the 
disc  issuing  from  the  darkness.     This  should  not  be  more  than  1°  or  2°. 

Another  good  method  is  that  of  Bjerrum,  in  which  the  light-sense  is 
tested  by  grey  letters  on  a  white  ground,  the  letters  being  constructed 
on  the  same  principle  as  Snellen's  Test  Types. 

A  useful  and  ready  clinical  method  consists  in  gradually  diminishing 
the  illumination  of  the  test-types  and  comparing  the  acuteness  of  vision 
of  the  patient  with  that  of  the  surgeon,  provided  the  latter  have  a  normal 
light-sense.  The  L.D.  is  most  affected  in  diseases  of  the  optic  nerve,  and 
the  L.M.  in  chorioido-retinal  affections  ;  but  the  measurement  of  the  foymer 
is  not  often  required  in  clinical  work. 


CHAP,  i.l      FUNCTIONAL  EXAMINATION  OF  THE  EYE,  11 


Retinal  Adaptation. — It  is  a  common  experience,  on  passing  from 
daylight  into  a  darkened  room,  to  find  that  at  first  nothing  is  visible, 
but  that  after  a  time  the  various  objects  in  the  room  begin  to  appear, 
until  final  y  almost  everything  can  be  seen.  This  phenomenon  is  called 
"  Adaptation  "  and  is  due  to  the  fact  that  the  retinal  purple,  which  has 
been  bleached  by  light,  is  only  gradually  regenerated.  In  testing  the 
light-sense,  therefore,  it  is  necessary  to  allow  some  time  for  the  eye  to  adapt 
itself.  Complete  adaptation  is  very  slow,  but  for  practical  purposes 
20  minutes  may  be  deemed  sufficient.  Adaptation  is  slower  at  the  macula 
lutea  than  ovitside  it,  probably  because  of  the  absence  of  rods,  which  alone 
contain  the  visual  purple. 

In  some  diseases,  such  as  retinitis  pigmentosa,  the  power  of  adaptation 
is  extremely  slow  and  defective,  and  gives  rise  to  night  blindness.  In- 
creased power  of  adaptation,  curiously  enough,  is  only  met  with  in  total 
colour-blindness. 

*  The  Colour-Sense  is  the  power  the  eye  has  of  distinguishing 
light  of  different  wave-lengths.  According  to  the  Young-Helm- 
holtz  theory,  the  retina  possesses  at  least  three  sets  of  colour-per- 
ceiving elements,  those  for  Red,  Green,  and  Blue  or  Violet.  These 
are  termed  primary  colours  because  by  their  combination  white 
light  as  well  as  all  other  colours  can  be  produced. 

According  to  Hering's  theory,  the  colour-sense  and  the  light- 
sense  depend  upon  chemical  changes  in  the  retina  or  in  the  visual 
substances  contained  in  the  retina.  He  suggests  the  existence 
of  three  different  visual  substances,  the  white-black,  the  red-green, 
and  the  blue-yellow,  by  the  using  up  or  Dissimilation,  and  restora- 
tion or  Assimilation  of  which  substances  the  sensations  of  light  and 
colour  are  produced.  These  theories  are  not  satisfactory,  for  they 
do  not  explain  cases  in  which  shortening  of  the  spectrum  occurs, 
and  many  other  facts  connected  with  colour-vision,  and  they  are 
not  founded  on  an  anatomical  basis.  Hering's  views  are  com- 
pletely disposed  of  by  the  discovery  that  the  electrical  reactions 
in  the  optic  nerve,  produced  by  stimulation  of  the  retina  by  different 
colours,  differ  only  in  degree  and  not  in  kind. 

Edridge-Green's  theory,  which  is  the  result  of  many  years'  study 
of  the  subject,  is,  that  light  falling  upon  the  retina,  liberates  the 
visual  purple  from  the  rods,  and  a  photograph  is  formed.  The  rods 
are  concerned  only  with  the  formation  and  distribution  of  the  visual 
purple,  not  with  the  conveyance  of  light  impulses  to  the  brain.  The 
decomposition  of  the  visual  purple  by  light  chemically  stimulates 
the    ends    of    the    cones    (very    probably    through    the   electricity 


12  DISEASES    OF    THE    EYE.  [chap.  i. 

which  is  produced),  and  a  visual  impulse  is  set  up,  which  is  con- 
veyed through  the  optic  nerve-fibres  to  the  brain.  The  character 
of  the  impulse  set  up  differs  according  to  the  wave-length  of 
the  light  causing  it.  Therefore  in  the  impulse  itself  we  have 
the  physiological  basis  of  the  sensation  of  light,  and  in  the 
quality  of  the  impulse  the  physiological  basis  of  the  sensation  of 
colour. 

Colour-vision,  therefore,  consists  in  the  power  of  distinguishing 
between  rays  of  different  wave-length,  and  the  greater  the  degree 
of  development  of  the  colour-perceiving  centre  in  the  brain,  the 
more  acute  will  be  the  power  of  distinguishing  differences  of 
wave-length,  consequently  the  smaller  will  be  the  interval  in  the 
spectrum  between  the  rays  which  are  recognised  as  different,  and 
therefore  the  more  numerous  will  be  the  colours  perceived.  When 
the  colour-perceiving  centre  is  badly  developed,  the  points  of  differ- 
ence will  be  greater,  that  is  to  say,  the  rays  perceived  as  different 
will  be  farther  apart  in  the  spectrum,  and  the  number  of  colours 
recognised  fewer — in  other  words,  there  will  be  blindness  for  one  or 
more  colours. 

It  may  also  happen  that  the  visual  purple  is  not  acted  upon  by 
the  rays  at  the  extreme  ends  of  the  spectrum,  and  then  the  spectrum 
will  appear  shortened. 

According  to  this  theory,  therefore,  the  colour-blind  are  divided 
into  two  distinct  classes  independent  of  each  other,  but  which  may 
be  associated.  The  first  class  includes  those  who  see  the  spectrum 
shortened  at  the  red  or  violet  ends,  or  at  both  ;  while  in  the  second 
the  number  of  colours  visible  in  the  spectrum  is  smaller  than  the 
normal.  A  consideration  of  the  way  in  which  the  colour-per- 
ceiving centre  develops,  according  to  Edridge-Green,  will  help 
us  to  understand  the  various  degrees  of  colour-blindness.  At 
first  no  difference  would  be  recognised,  the  whole  spectrum 
would  appear  of  a  neutral  colour.  In  the  next  stage  only  the 
extreme  ends  of  the  spectrum  would  be  differentiated,  namely, 
the  red  and  violet,  with  a  more  or  less  wide  neutral  band  of  grey 
between  them ;  the  grey  band  would  gradually  diminish  until 
the  two  colours  met ;  following  on  this  stage  a  third  colour  would 
appear  at  the  next  point  of  greatest  difference,  namely,  at  the 
centre  of  the  spectrum  in  the  green,  and  so,  in  order  of  succession, 
yellow,  blue,  and  orange  would  be  added.      Thus,  if  the  normal- 


CHAP.  I.J      FUNCTIONAL  EXAMINATION  OF  THE  EYE.  13 

sighted  be  designated  as  liexacliromic  (seeing  six  colours)  ,i  the  colour- 
blind may  be  divided  into  the  pentachromic  (seeing  five  colours 
— red,  yellow,  green,  blue,  violet),  the  tetrachromic  (seeing  four — 
red,  yellow,  green,  violet),  the  trichromic  (seeing  three — red, 
green,  violet),  the  dichromic  (seeing  two — red  and  violet),  and 
finally,  the  monochromic,  or  totally  colour-blind. 

It  must  be  remembered,  however,  that  all  grades  of  transition 
exist  between  total  colour-blindness  and  a  normal  colour-sense, 
so  that  even  in  one  class,  say  the  dichromic,  it  is  difficult  to  find 
two  colour-blind  persons  who  will  behave  exactly  alike  with  all 
tests. 

Colour  Tests. — Testing  the  colour-sense  is  by  no  means  a  simple 
matter.  It  requires  a  good  deal  of  experience,  as  well  as  a  know- 
ledge of  colour-blindness  and  of  the  eye  itself,  to  apply  the  tests  in 
a  really  satisfactory  way.  It  is  advisable  therefore  that  they  should 
not  be  entrusted  to  laymen,  or  even  scientists,  but  should  be  carried 
out  by  ophthalmologists. 

The  spectrum  affords  the  most  accurate  of  all  tests,  but  a  special 
spectroscope  is  required,  and,  owing  to  the  expense  and  expert 
knowledge  necessary,  as  well  as  to  the  fact  that  a  certain  degree 
of  intelligence  on  the  part  of  the  patient  is  required,  it  is  hardly 
suitable  for  clinical  use. 

It  is  now  almost  universally  admitted  that  Holmgren's  coloured 
wool  test  is  inadequate  as  an  efficient  test. 

Edridge-Green  uses  two  tests,  a  classification  test  and  a  lantern 
test.  The  Classification  Test  consists  of  a  number  of  coloured  beads 
in  which  every  variety  of  confusion  colour  of  the  colour  blind  is 
well  represented,  and  a  box  with  four  compartments  into  which 
the  beads  can  be  dropped.  The  aperture  to  each  of  the  compart- 
ments is  such  that  the  observer  cannot  see  the  bead  after  it  has 
been  dropped  into  the  box.  The  four  compartments  of  the  box  are 
labelled  Red,  Yellow,  Green  and  Blue.  The  examinee  is  told  to, 
pick  out  from  the  beads  in  front  of  him,  which  are  placed  on  the 
white  porcelain  lining  of  the  box,  all  those  that  are  red,  keeping 
as  nearly  as  possible  to  the  exact  hue,  but  selecting  those  that  are 
lighter  or  darker  of  the  same  colour,  and  to  drop  them  one  by  one 
into  the  compartment  labelled  Red.     He  then  goes  through  the 

1  In  very  rare    cases  a   seventh    colour,   called    ind'go,  is    seen  in  the 
spectrum. 


U  DISEASES    OF    THE    EYE.  [chap.  i. 


same  process  with  the  three  other  colours  ;  he  is  not  allowed  to 
compare  the  colours  directly,  but  must  select  them  entirely  according 
to  the  name  which  he  gives  to  the  colour.  It  will  be  found  that 
whilst  the  normal-sighted  are  able  to  select  the  correct  colours 
with  the  greatest  ease,  the  colour-blind  will  make  their  characteristic 
mistakes.  This  test,  like  the  lantern,  will  detect  cases  of  colour 
scotoma  as  well  as  those  of  ordinary  colour-blindness. 

The  Lantern  Test,  which  is  very  efficient  and  practical,  consists 
of  a  lantern  with  coloured  glasses  revolving  behind  a  circular 
opening  which  can  be  altered  in  diameter.  The  colours  can  be  shown 
separately  or  combined,  and  can  be  modified  by  neutral  or  ribbed 
glass,  so  as  to  represent  signals  as  they  are  affected  by  distance? 
fog,  or  rain.  It  forms  an  ideal  test  for  railway  servants  and  sailors. 
The  examinee  is  asked  to  name  the  colour  of  the  light  shown.  The 
use  of  colour  names  is  absolutely  necessary,  or  normal-sighted 
persons  will  be  rejected,  through  paying  attention  to  shade  rather 
than  to  colour.  It  does  not  matter  what  name  is  applied  to  a  colour  ; 
but  ground  for  rejection  is  afforded  when  the  examinee  calls  two  of 
the  main  colours  of  the  normal-sighted,  as,  for  instance,  red  and 
green,  by  the  same  name. 

Since  all  grades  of  colour-blindness  exist,  the  practical  question 
therefore  is  to  draw  the  line  at  which  rejection  should  take 
place. 

The  following  should  be  rejected  as  being  dangerously  colour- 
blind :  1.  Those  who  see  only  three  colours  (trichromics),  or  less 
than  three.  2.  Those  who  have  a  shortened  red  end  in  their  spec- 
trum, even  though  they  may  be  hexachromics.  3.  Those  affected 
with  central  scotoma  for  red  or  green. 

Stilling's  test,  in  which  spots  of  a  given  colour  are  printed  on 
a  background  of  a  confusion  colour,  finds  favour  with  some. 

Colour-blindness  is  either  congenital  or  acquired.  Congenital 
colour-blindness  occurs  in  3 '5  per  cent,  of  men  and  less  than  1  per 
cent,  of  women.  It  is  hereditary,  but  is  transmitted  by  females 
with  normal  colour  sense. 

Acquired  colour-blindness*  is  found  in  toxic  amblyopia,  in  atrophy 
of  the  optic  nerve,  and  in  some  other  conditions. 

The  Form-Sense  (Acuteness  of  Vision). — By  Acuteness  of  Vision 
(V)  is  meant  the  power  which  the  eye,  or  rather  the  macula  lutea, 
has  of  distinguishing  form,  any  anomaly  of  its  refraction,  if  such 


CHAP.  I.]         FUNCTIONAL  EXAMINATION  OF  THE  EYE.         15 


exist,  having  been  first  corrected.  In  clinical  ophthalmology 
the  testing  of  this  function  is  an  important  and  ever-recurring 
duty. 

When  applied  to  by  a  patient  on  account  of  imperfect  sight 
it  is  our  first  duty,  as  a  rule,  to  ascertain  accurately  the  condition 
of  refraction  and  accommodation  of  his  eyes.  Should  these  be 
abnormal,  and  it  be  found  that  by  aid  of  the  correcting  glasses 
perfect  vision  is  obtained,  it  may,  in  general,  be  concluded  that  the 
eye  is  organically  sound,  and  that  the  patient's  complaints  are  due 
to  the  defect  in  accommodation  or  refraction.     If  glasses  do  not 


Fig.  8. 


restore  perfect  vision,  we  must  then,  by  the  ophthalmoscope  and 
other  methods,  decide  the  nature  of  the  defect. 

Now,  in  order  to  measure  the  acuteness  of  vision  we  must  have 
a  normal  standard  for  comparison — i.e.,  we  must  find  what  is  the 
size  of  the  smallest  retinal  image  whose  form  can  be  distinguished. 
We  cannot,  of  course,  measure  this  image  on  the  retina  directly  ; 
but,  as  its  size  is  proportional  to  the  visual  angle — the  angle  which 
the  object  subtends  at  the  eye — it  is  sufficient  to  determine  the 
smallest  visual  angle  under  which  the  form  of  an  object  can  be 
distinguished.  It  has  been  found,  experimentally,  that  the  average 
size  of  this  angle  is  5  minutes  (Fig.  8).^ 

In  order  practically  to  ascertain  the  degree  of  acuteness  of  vision 
we  place  our  patient  with  his  back  to  the  light,  while  facing  him 
at  a  distance  of  6  metres,  and  in  good  light,  are  placed  Snellen's 
Test-Types  for  distance.  These  types  are  so  designed  that,  at  the 
distance  at  which  they  should  be  seen,  they  each  subtend  an  angle 


^  The  minimum  separabile  or  smallest  angle  under  which  two  points 
can  be  distinguished  is  1  minute,  and  corresponds  approximately  with  the 
distance  between  three  retinal  cones,  the  central  one  not  being  stimulated. 


16  DISEASES    OF    THE    EYE.  [cHAt.   I. 


of  5'  at  the  eye.  The  largest  type  should  be  seen  at  60  metres 
(Fig.  8)  by  the  normal  eye,  and  the  types  range  from  this  down 
to  a  size  visible  not  farther  off  than  6  metres.  If  V=Acuteness 
of  Vision,  d  =  the  distance  from  the  eye  to  be  tested  to  the  test- 
types,  and  D  =  the  distance  at  which  the  type  should  be  distin- 
guishable, then  V  =  ^.  For  example :  if  d  =  6  metres  (a  distance 
which  most  rooms  can  command),  and  if  the  eye  see  type  D  =  6, 
then  V  =  f  =  1,  or  normal  V.  ;  but  if  at  6  metres  the  eye  see 
only  D  =  60,  which  should  be  seen  at  60  metres,  then  V  =  -^^, 
in  short  V  =  6  divided  by  the  number  of  the  type  read.  A  distance 
of  6  metres  is  selected  because  the  test-types  are  also  used  to  test 
the  refraction,  and  at  that  distance  the  rays  proceeding  from  the 
type  may  be  considered  to  be  parallel. 

In  practice  these  fractions  must  not  be  taken  in  a  strict  mathe- 
matical sense.  For  example,  /^  does  not  mean  that  a  patient  with 
that  degree  of  V  has  his  visual  capacities  lessened  by  one-half. 

A  series  of  types  resembling  the  letter  E,  in  various  positions, 
is  also  used  for  testing  illiterates.  Or,  better  still,  an  incomplete 
circle  like  the  letter  C  in  different  positions  can  be  used,  the  patient 
being  required  to  tell  where  the  break  in  the  circle  is  placed.  This 
has  lately  been  recommended  as  a  universal  test.  The  types  of 
Jaeger  for  near  vision  are  sometimes  used  for  testing  the  acuteness 
of  V. 

Should  the  patient's  sight  be  so  defective  that  he  is  unable  to 
read  any  of  the  letters,  it  may  be  tested  by  finding  at  what  distance 
he  can  count  the  surgeon's  fingers  ;  and  if  he  cannot  even  do  that, 
then  his  power  of  perception  of  light  (his  P.L.)  should  be  tested. 
This  is  done  by  means  of  a  lamp  in  a  dark  room,  the  eye  being 
alternately  covered  and  uncovered,  and  the  patient  being  required 
to  say  when  it  is  "  light "  and  when  "  dark."  If  the  flame  be 
gradually  lowered  the  smallest  degree  of  illumination  perceptible 
will  be  ascertained. 

The  eyes  must  be  examined  separately,  that  one  not  under 
examination  being  excluded  from  vision  by  being  shaded  with  the 
patient's  own  hand  or  other  suitable  screen  ;  but  it  must  not  be 
at  all  pressed  on,  as  ^ny  pressure  would  dim  its  vision  when  its 
turn  for  examination  may  come.  When  a  trial  frame  is  put  on, 
the  patient  should  not  be  allowed  to  turn  his  face  to  one  side,  or  else 
he  may  be  with  the  eye  which  is  covered. 


CHAP.  I.]      FUNCTIONAL  EXAMINATION  OF  THE  EYE.  17 


With  the  advance  of  age  the  acuteness  of  vision  undergoes 
a  slight  but  steady  reduction,  owing  to  certain  senile  changes  in 
the  eye. 

THE   FIELD   OF   VISION. 

By  the  Field  of  Vision  (F.V.)  is  meant  the  space  within  which 
objects  can  be  seen  by  one  eye,  the  other  being  closed,  the  gaze  of 
the  former  being  fixed  on  some  one  object  or  point.  Thus,  if  stand- 
ing on  a  hill,  we  fix  the  gaze  of  one  eye  on  some  object  on  the  plain 
below,  the  field  of  vision  includes  not  only  that  object,  but  many 
others  also  for  miles  around  it. 

The  fixation  object  is  seen  by  central  or  direct  vision,  its  image 
being  formed  on  the  macula  lutea  ;  the  other  objects  in  the  field 
of  vision  correspond  with  as  many  different  points  in  the  more 
peripheral  parts  of  the  retina,  and  are  seen  by  eccentric,  or  indirect, 
vision.  Eccentric  vision  is  of  great  importance  for  guiding  oneself 
and  for  the  avoidance  of  obstacles.  This  may  be  realised  by  the  ex- 
periment of  looking  through  a  long  small-bore  cylinder  {e.g.,  a  roll 
of  music)  with  one  eye,  thus  cutting  off  its  eccentric  field,  while 
the  other  eye  is  closed. 

The  Examination  of  the  Field  of  Vision  (Perimetry)  is  carried 
out  for  clinical  purposes  by  means  of  an  instrument  called  the  peri 
meter.  This  is  a  semicircular  arc  of  metal  capable  of  revolving 
upon  its  middle  point,  so  as  to  describe  a  hemisphere  in  space.  The 
arc  is  divided  into  degrees  from  0°  at  its  middle  point,  to  90°  at 
either  extremity.  At  the  centre  of  the  hemisphere  is  situated  the 
eye  under  examination,  while  the  fixation  point  is  placed  exactly 
opposite,  in  the  middle  of  the  semicircle,  at  0°.  The  test  object, 
a  small  bit  of  white  paper  5  or  10  mm.  square,  is  slowly  moved 
along  the  inner  surface  of  the  arc  from  the  periphery  towards  the 
centre,  until  it  comes  into  view,  and  the  observation  is  repeated  in 
various  meridians.  The  horizontal,  vertical,  and  two  intermediate 
meridians,  at  least,  should  be  examined  by  placing  the  arc  of  the 
perimeter  in  the  corresponding  planes.  The  patient's  eye  must 
be  carefully  watched,  as  any  movement  of  it  away  from  the  fixation 
point  would  vitiate  the  results. 

The  boundary  of  the  field  is  noted  on  a  diagram  or  chart  (Fig.  9) , 
which  represents  the  projection  of  a  sphere  on  a  plane  surface. 
The  radii  represent  different   meridians,   and  are  indicated  by  a 


18 


DISEASES    OF    THE    EYE. 


[chap.  i. 


dial  with  pointer  on  the  back  of  the  perimeter,  while  the  concentric 
circles  correspond  with  the  degrees  marked  on  the  arc.  A  pencil 
mark  is  placed  on  the  chart  at  the  spot  corresponding  with  that  on 
the  perimeter  at  which  the  test  object  comes  into  view  ;  and,  when 
the  different  meridians  have  been  examined,  these  marks  are  united 
by  a  continuous  line,  which  then  represents  the  outer  boundary 
of  the  F.V.     In  some  cases  (hemianopsia,  etc.)  it  is  better  to  take 


Right  Eye 
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Fig.   9. 

the  field  by  the  circular  method,  i.e.,  by  placing  the  test  object 
successively  on  the  different  degrees  of  the  arc,  and  each  time 
rotating  the  arc  through  a  complete  circle,  the  points  or  meridians 
at  which  the  object  appears  and  disappears  from  view  being  noted. 
The  normal  F.V.  is  not  circular,  but  extends  outwards  about 
95°,  upwards  about  53°,  inwards  about  47°,  and  downwards  about 
65°,  as  represented  by  the  strong  curve  in  Fig.  9.  The  limitation 
upwards  and  inwards  is  partly  due  to  the  projection  of  the  supra- 
orbital margin  and  the  bridge  of  the  nose,  but  also  to  the  fact  that 
the  outer  and  lower  parts  of  the  retina  are  less  practised  in  seeing 
than  are  the  upper  and  inner  parts,  and  their  functions  consequently 


CHAP,  i.j      FUNCTIONAL  EXAMINATION  OF  THE  EYE.  iw 

less  developed.  The  acuteness  of  vision  diminishes  progressively 
towards  the  periphery  of  the  field,  two  points  of  a  certain  size  close 
together  being  distinguishable  from  each  other  only  a  short  distance 
from  the  fixation  point,  while  the  farther  towards  the  periphery 
the  larger  must  be  the  test  objects. 

Fig.  10  serves  to  illustrate  the  projection  of  the  field  of  vision 
of  the  right  eye  on  the  semicircle  of  the  perimeter  to  its  extreme 
temporal  (95°)  and  its  extreme  nasal  (47°)  boundaries,  as  well  as 
the  portion  of  the  retina  {a  to  b)  which  corresponds  with  this  extent 
of  field  ;    and  it  shows  that  the  sensitive  portion  of  the  retina,  or 


Fig.  10. 


rather  perhaps  the  portion  of  the  retina  which  is  most  used,  ex- 
tends farther  forward  on  the  nasal  than  on  the  temporal  side.  The 
diagram  also  explains  the  remarkable  fact  that  the  field  extends  in 
the  temporal  direction  more  than  90°. 

The  Blind  Spot  of  Mariotte  is  a  small  blind  island  or  scotoma 
in  the  F.V.  It  takes  the  shape  of  an  oval  with  the  long  axis  vertical, 
whose  centre  is  situated  about  15°  to  the  outer  side  of  the  point  of 
fixation  and  just  below  the  horizontal  meridian.  It  is  shown 
as  a  dark  spot  in  Fig.  9.  It  is  due  to  the  optic  papilla  (optic  disc), 
for  at  that  place  the  outer  layers  of  the  retina  are  wanting,  and 
hence  it  possesses  no  power  of  perception. 


20 


DISEASES    OF    THJS    EYE. 


[CHAt*.    1. 


For  the  detection  of  small  defects  such  as  enlargement  of  the 
blind  spot  and  central  scotomata  in  the  early  stage,  it  is  necessary 
to  employ  Bjerrum's  Method,  in  which  the  observations  are  made 
with  a  black  (velvet)  screen  at  a  distance  of  1  or  2  metres,  using 
a  very  small  test  object,  of  1  or  2  mm.,  or  Priestley  Smith's 
scotometer  may  be  used.  The  field  of  vision  when  taken  in  this 
way  is  much  smaller,  and  is  approximately  circular,  measuring 
about  30°.  An  exact  record,  therefore,  of  a  perimetric  examination 
should  give  the  size  of  the  test  object  and  its  distance  from  the 
patient's  eye  ;  these  particulars  are  then  entered  as  a  fraction  having 
the  former  as  numerator  and  the  latter  as  denominator. 

The  presence  of  a 
gross  alteration  in  the 
field  may  be  roughly 
ascertained  if  the  ob- 
server face  the  patient, 
who  has  his  back  to 
the  light,  and  use  his 
own  hand  as  a  test  ob- 
ject. The  eye  of  the 
observer  which  is  oppo- 
site the  patient's  eye 
serves  as  a  control,  as 
its  field  can  be  tested 
at  the  same  time  as 
that  of  the  patient's 
eye. 
In  the  Binocular  Field  of  Vision,  since  the  two  visual  lines  meet 
at  the  fixation  point,  the  central  portion  is  common  to  both  eyes 
(Fig.  11). 

*  Pathological  Defects  in  the  Field  of  Vision.— As  these  are 
often  of  great  diagnostic  importance,  it  will  be  advisable  to  give  a 
summary  of  the  various  types  which  are  met  with. 

Pathological  alterations  of  the  fields  of  vision  may  be  divided 
into  (1)  Contractions  of  the  field  which  begin  at  the  periphery, 
(2)  Insular  defects,  and  (3)  Loss  of  a  half  of  the  field,  usually  affecting 
both  eyes  and  extending  to  the  middle  line. 

Contractions  of  the  visual  field  may  be  {a)  concentric  as  in 
atrophy  of  the  optic  nerve  (Fig.  12),  retinitis  pigmentosa,  and  hys- 


FiG.  11. — Binocular  Field  of  Vision.  The 
white  area  is  common  to  both  eyes,  P  being 
the  fixation  point.  The  shaded  portion  on  the 
right  belongs  to  the  right  eye  alone,  while  that 
on  the  left  belongs  to  the  left  eye  alone. 


Left  Eye 


temp 


temp 


Fig.   12. — Extreme  concentric^con-  Fig.  13. — F.V.  from  case  of  Glaucoma, 

traction  of  F.V.    in    atrophy  of    the 
optic  nerve. 


160  '80 


Fig.   14. — Sector  defect  in  F.V.  from  branch  embolism  of  the  central 
artery  of  the  retina. 


left  Eye 


160  '80 

Fig.   1 5.— Sector-like  defects  in  F.V.  from  case  of  disseminated  sclerosis. 


22 


DISEASES    OF    THE    EYE. 


[chap. 


terical  amblyopia  or  (6)  the  defect  may  begin  at  a  certain  part 
of  the  periphery,  as  in  glaucoma  (Fig.  13),  where  the  nasal  side  is 
the  first  to  become  affected,  or  as  in  detachment  of  the  retina,  when 
the  portion  of  the  field  which  is  lost  will  depend  on  the  position 
of  the  detachment.  If  this  be  below,  as  is  most  commonly  the  case, 
then  the  defect  in  the  field  will  of  course  be  above,  (c)  Sometimes 
the  defect  is  irregular,  or  sector-like  ;  examples  of  this  variety  of 
field  occur  in  embolism  of  a  branch  of  the  central  artery  of  the 
retina  (Fig.  14),  and  in  some  cases  of  atrophy  of  the  optic  nerve 
associated  with  tabes  or  multiple  sclerosis  (Fig.  15). 

An  insular  defect,  which  is  termed  a  scotoma,  may  be  central, 


ISO  180 

Fig.    l(i. — Central  scotoma  for  red  and  green  in  toxic  amblyopia. 


that  is,  involving  the  fixation  point,  or  paracentral,  in  close  proximity 
to  it,  or  again  it  may  be  situated  in  any  part  of  the  remaining  field. 
A  central  scotoma  is  an  important  symptom  in  toxic  amblyopia 
(e.g.  from  Tobacco  and  Alcohol  poisoning.  Fig.  16)  and  in  retrobulbar 
neuritis  due  to  other  causes,  such  as  disease  of  the  posterior  nasal 
accessory  sinuses.  It  sometimes  makes  its  appearance  in  the  very 
earliest  stage  of  multiple  sclerosis.  In  the  cases  just  mentioned  both 
eyes  are  affected,  whereas  the  scotoma  following  on  disease  of  the 
macula  lutea  is  often  unilateral.  Non-central  scotomata  may  arise 
from  retinal  haemorrhages  (Fig.  17),  intra-ocular  tumours  (Fig.  18), 
and  disseminated  chorioiditis. 

A  peculiar  form  of  scotoma  is  the  annular  or  ring-scotoma  which 


Lef)  Eye 


lUyhtEyc 


Fig.    17. — Scotoma    in    the    F.V.  Fig.   18. — Large     scotoma     caused 

caused  by  a  large  retinal  haemorrhage.        by  an  intra-ocular  sarcoma. 


Fig.    19. — Irregular  annular  scotoma  due  to  specific  chorioido-retinitis. 


80  80] 


7    r~7ioo  100 


Fig.  20. — Bitemporal  hemianopsia  in  a  case  of  pituitary  disease  which  proved  fatal. 


24  DISEASES   OF   THE   EYE.  [chap.  i. 

surrounds  the  fixation  point,  without  involving  it.  It  is  met 
with  in  retinitis  pigmentosa  and  in  syphilitic  chorioido-retinitis 
(Fig.  19).  ^ 

3.  Hemianopsia  will  be  dealt  with  more  particularly  in  chap.  xiv. 
When  the  right  or  left  halves  of  both  fields  are  lost,  the  condition 
is  termed  Homonymous  Hemianopsia.  If  both  temporal  halves 
are  blind  then  we  have  a  Bitemporal  Hemianopsia.  The  commonest 
cause  of  the  former  is  a  haemorrhage  in  the  mesial  surface  of  the 
occipital  lobe,  and  of  the  latter  tumour  of  the  pituitary  body  (Fig. 
20).  In  some  instances  a  quarter  of  the  field  only  is  lost  in  each  eye ; 
but  this  is  merely  an  incomplete  form  of  hemianopsia. 

A  defect  in  the  field  is  Positive  if  it  be  visible  to  the  patient  as  a 
dark  area.  Negative  if  it  be  invisible.  If  the  blindness  be  complete, 
the  defect  is  said  to  be  Absolute  ;  but  if  the  acuteness  of  vision 
be  merely  diminished,  it  is  said  to  be  Eelative.  A  relative  defect 
may  exist  for  colours  only  (Fig.  16),  most  commonly  for  red 
and  green.  In  all  eyes  the  blind  spot  is  a  negative  and  absolute 
scotoma  in  the  field  of  vision.  When  the  vision  is  too  defective 
to  permit  of  the  field  of  vision  being  tested  in  the  ordinary  way, 
the  patient  may  be  asked  to  indicate  the  position  of  a  light  placed 
in  different  parts  of  the  field  ;  this  is  called  testing  the  Projection  of 
Light. 

The  Perception  of  Colours  in  the  Periphery  of  the  Field  can  be 
examined  with  the  perimeter,  by  means  of  bits  of  coloured  paper 
not  more  than  5  mm.  square.  It  has  been  in  this  way  ascertained 
that  the  boundaries  of  the  power  of  eccentric  perception  for  the 
different  colours  do  not  seem  to  correspond  with  the  boundary  for 
white  light,  nor  do  the  boundaries  of  the  different  colours  seem  to 
incide.  Examining  from  the  periphery  towards  the  centre  by 
ordinary  daylight,  blue  is  the  colour  which  can  be  distinguished  as 
such  most  eccentrically,  its  field  extending  nearly  as  far  as  the  general 
F.V.  ;  then  come  yellow,  orange,  red,  and,  with  the  most  limited 
field,  green.  Blue,  red,  and  green  being  the  most  important,  their 
fields  are  noted  in  Fig.  9.  Although  the  respective  colours  are 
distinguishable  within  the  limits  indicated,  they  are  by  no  means 
so  brilliant  in  hue  as  when  seen  by  direct  vision.  It  has,  however, 
been  demonstrated  that  every  colour  is  recognisable  up  to  the  outer 
limit  of  the  F.V.,  if  the  coloured  object  be  of  sufficient  surface  and 
be  sufficiently  illuminated;  so  that  there  is,  in  fact,  no  absolute 


CHAP.  I.]    FUNCTIONAL  EXAMINATION   OF  THE   EYE.  25 

colour-blindness  in  the  peripheral  parts  of  the  retina,  but  merely 
a  diminished  sensitiveness  to  coloured  light. 

Pathological  Changes  in  the  Colour  Fields  need  only  be  referred 
to  briefly.  The  most  important  are  :  (1)  The  central  scotoma  for 
red  and  green  which  occur  in  toxic  amblyopia  (Fig.  16).  (2)  The 
concentric  contraction  of  the  colour  fields  in  atrophy  of  the  optic 
nerves,  which  often  precedes  the  failure  for  white,  and  in  the  later 
stages  progresses  more  rapidly,  so  that  the  field  for  colours  is  rela- 
tively more  reduced  in  size  than  that  for  white.  (3)  A  hemianopsia 
may  also  exist  for  colours  only  (see  chap.  xiii.  part  1),  to  be 
followed  later  by  loss  of  the  half  fields  for  white.  (4)  Finally 
the  normal  order  of  the  boundaries  of  the  fields  for  the  different 
colours  may  be,  to  a  certain  extent,  reversed,  or  instead  of  being 
concentric  they  may  overlap.  These  conditions  have  been  observed 
in  cerebral  tumours  and  in  hysteria. 

That  colour  defects  can  exist  alone,  does  not  require  the  assump- 
tion of  the  existence  of  a  separate  cortical  centre  for  colour  vision ; 
indeed,  facts  seem  rather  to  support  the  view  that  lesions  of  the 
visual  nerve  fibres  interfere  more  easily  with  the  transmission  of  those 
impulses  which  produce  colour  vision,  than  with  those  which  cause 
the  sensation  of  white. 

The  Perception  of  Form  in  the  Perifhery  of  the  Field  is  very 
defective,  and  its  examination  is  not  of  much  practical  importance  ; 
but  this  portion  of  the  field  is  very  sensitive  to  the  movement  of 
objects. 

Enlargement  of  the  Blind  Spot  occurs  in  cases  of  opaque  nerve  fibres, 
posterior  staphyloma,  and  optic  neuritis,  but  of  late  it  has  been  pointed 
out  that  an  increase  in  size  of  the  blind  spot  for  white  or  colours  is  one  of 
the  earliest  signs  of  involvement  of  the  optic  nerve  in  disease  of  the  posterior 
nasal  accessory  sinuses  and  appears  before  the  central  scotoma.  Accord- 
ing to  Van  der  Hoeve  the  blind  spot  measures  on  an  average  about  7° 
vertically,  5°  horizontally,  and  is  surrounded  by  a  colour-blind  area  of  less 
than  1°. 


CHAPTER    II. 


THE   OPHTHALMOSCOPE. 


Before  proceeding  to  describe  the  ophthalmoscope,  a  brief  statement 
of  the  properties  of  plane  and  concave  reflecting  surfaces  (or  mirrors)  will 
be  of  use. 

Laws  of  Reflection. — When  a  ray  of  hght,  O  S  (Fig,  21),  meets  a  polished 
surface  or  mirror,  M  M,  at  a  given  point,  S,  the  angle  of  incidence,  i,  formed 
with  the  perpendicular  to  the  surface,  P,  is  equal  to  the  angle  of  reflection, 

r,  and  the  incident  and  reflected  rays  O  S, 
S  R,  lie  in  one  plane. 

Images  formed  by  a  Plane  Mirror. — To 
an  observer  placed  at  R  the  point  O 
would  seem  to  be  at  I,  where  the  prolonga- 
tion of  R  S  intersects  the  line  I  O  per- 
pendicular to  the  mirror,  and  O  M  is 
equal  to  M  I.  Similarly  the  image  of  the 
point  B  is  found  on  the  perpendicular 
B  E,  E  D  being  equal  to  D  B.  The 
image  I  E  therefore,  formed  by  a  plane 
mirror,  is  virtual,  erect,  and  situated 
behind  the  mirror  &X  the  same  distance 
from  it  as  the  object  O  B. 

Images  formed  by  a  Concave  Mirror. — 
In  Fig.  22,  c  is  the  centre  of  curva- 
ture of  the  mirror  M  M.  The  rays  a,  b, 
parallel  to  the  axis  S  /,  meet  the  surface  of  the  mirror  at  M  and  M'  and 
are  reflected  to  F  the  principal  focus.  The  angle  of  incidence  a  M  c  being 
equal  to  the  angle  of  reflection  F  M  c,  the  radius  c  M  being  perpendicular 
to  the  surface  of  the  mirror  at  M,  F  lies  midway  between  S  and  c  ;  that  is  to 
say,  the  focal  length  of  a  concave  mirror  is  equal  to  half  the  radius.  Rays 
from  a  point  /,  beyond  c,  are  made  to  converge  at  /',  between  F  and  c, 
and  the  farther  away  /  is  the  nearer  will  /'  be  to  F  ;  /  and  /'  are  con- 
jugate foci.  The  conjugate  focus  of  a  point  nearer  the  mirror  than  F 
would  be  virtual,  because  the  rays  then  diverge  after  reflection. 

In  ophthalmoscopic  work  the  source  of  light  is  usually  farther  away 
than  the  centre  of  curvature  of  the  mirror,  and  Fig.  23  shows  how,  in  this 
case,  a  real  inverted  and  diminished  image  of  the  light  is  formed.  The 
image  of  the  point  O  is  found  at  I,  the  point  of  intersection  of  the  ray 

26 


Fig.  21. — Reflection  by  a 
plane  mirror. 


THE    OPHTHALMOISCOPE. 


27 


O  I,  which  passes  through  the  centre  of  curvature  C,  without  deviation, 
and  the  ray  O  S  parallel  to  the  axis,  which  passes  through  the  principal 
focus  F,  after  reflection  ;  the  image  of  the  point  B  is  found  in  a  similar 
manner.  As  O  B  ap- 
proaches C,  I  M  also 
approaches  it,  and  in- 
creases in  size  until  at 
C  object  and  image 
are  of  equal  size  and 
coincide.  When  the 
object  lies  between  F 
and  the  mirror,  a  vir- 
tual, erect,  magnified 
image  is  seen.  A  con- 
cave mirror  therefore 
resembles  a  convex  lens  in  its  action  (chap,  xv.,  §  5.) 


Fig.  22. — Reflection  by  a  concave  mirror. 


To  distinguish  a  Plane  from  a  Concave  Mirror  the  student  should 
stand  with  his  back  to  the  source  of  light  and,  with  the  ophthal- 
moscope held  in  front  of  him  and  a  little  to  one  side,  should  throw 
the  light  reflected  from  it  into  his  own  eye  ;  he  will  then  see  an 
erect  image,  if  the  mirror  be  plane,  or  an  inverted  image,  if  the 
mirror  be  concave.  A  simpler  method  consists  in  facing  the  source 
of  light,  and  throwing  the  reflected  light  on  a  screen,  say  the  palm 
of  the  hand,  and  moving  the  mirror  towards  or  away  from  it ;  then, 
if  the  mirror  be  plane,  a  round  image  with  a  dark  central  spot 
will  be  formed  at  all  distances  ;    but.  if  the  mirror  be  concave,  at 

a  certain  distance 
an  inverted  image 
of  the  source  of 
light  will  be  formed. 
The  Ophthalmo- 
scope  .—Although 
the  dioptric  media 
of  an  eye  may  be 
perfectly  clear  and 
normal,  yet  no  de- 
tail of  its  fundus 
can  be  discerned  by 
the  unaided  eye  of  an  observer  who  looks  through  the  pupil,  the 
latter  being  for  him  merely  a  dark  opening.  The  reason  of  this 
is,  that  light  can  only  enter  the  eye  through  the  pupil  and 
the  refractive  media.     In  albinos  the  pupil  appears  red,  because 


Fig.  23. — Image  formed  by  a  concave  mirror 
when  the  object  is  beyond  the  centre  of  cur- 
vature. 


DISEASES    OF    THE    EYE. 


[chap.   II. 


the  absence  of  the  uveal  pigment  allows  the  light  to  penetrate  the 
sclerotic  and  illumine  all  the  interior  of  the  eye  in  a  diffuse  manner. 
To  explain  : — Suppose  the  inside  of  a  small  box  {vide  Fig.  24)  to  be 
blackened,  and  on  its  floor  some  printed  letters  fastened,  and  a  hole 
cut  in  the  lid,  which  is  then  replaced — it  will  be  found  that,  by  aid 


Fig.  24. 

of  a  lighted  candle  and  with  a  little  experimentation,  the  letters 
may  be  read  through  the  aperture.  The  rays  passing  from  the 
light  (L)  into  the  box  through  the  aperture  illuminate  the  opposite 
surface,  and  from  this  surface  the  rays  a.  h,  and  others  pass  out 
again  through  the  opening,  and  some  of  them  fall  into  the  observer's 
eye  at  E. 

But  if,  in  order  to  make  this  box  represent  an  eye,  we  place  a 
convex  lens,  71,  of  the  proper  strength,  immediately  within  the 
aperture,  all  the  rays  passing  into  the  box  (Fig.  25)  from  L  are 
brought  to  a  focus  on  its  opposite  side  at  m  by  the  convex  lens  n, 


Fig.  25. 


and,  according  to  the  law  of  conjugate  foci  (§  17,  chap.  xv.).  all  the 
rays  passing  out  from  the  box  meet  again  at  the  source  of  light  (L), 
and  hence  none  of  them  can  be  received  by  the  eye  (a)  of  the  observer  ; 
nor  can  this  eye  be  placed  in  any  position  where  it  could  receive 
any  of  these  rays,  for  if  it  be  placed  anywhere  between  the  aperture 
and  L,  it  would  cut  off  the  light  passing  from  L  into  the  box. 


CHAP.   II.]  THE    OPHTHALMOSCOPE.  '20 


If  the  back  of  the  box  were  further  forward,  the  light  would 
not  be  focussed  on  it,  and  the  emergent  rays  would  form  parallel 
or  conical  divergent  beams  passing  back  to  and  surrounding  L. 
In  the  latter  case,  if  an  observer  held  his  eye  close  beside  the  light, 
some  of  the  divergent  rays  would  enter  it,  and  the  letters  would  be 
visible.  This  explains  the  red  pupil  often  seen  in  hypermetropia 
and  aphakia. 

Hehnholtz's  Ophthalmosco'pe. — If  the  eye  of  the  observer  could 
itself  be  made  the  source  of  light,  the  difficulty  would  be  solved  ; 
and,  practically,  this  is  what  Helmholtz  accomplished  with  his 
ophthalmoscope  in  the  year   1851.     The  instrument  he  invented 


Fig.   26. 

was  composed  of  a  number  of  small  plates  of  glass  {0,  Fig.  26),  from 
which  light  from  L  was  reflected  into  the  eye  (E),  and  thus  the 
fundus  of  the  latter  was  illuminated.  From  m  rays  pass  back  again 
by  the  same  path  to  the  ophthalmoscope,  some  being  reflected 
back  to  L ;  but  some,  passing  through  the  ophthalmoscope,  and 
falling  into  the  observer's  eye  placed  close  behind  the  instrument 
at  a,  form  in  it  an  image  of  m. 

Modern  Ophthalmoscope. — For  the  original  ophthalmoscope  of 
Helmholtz  a  concave  mirror  of  20  cm.  focal  length  with  a  central 
opening  has  been  substituted.  This  mirror  (0,  Fig.  27)  throws 
convergent  rays  into  the  eye  {E)  ;  and  these,  being  made  more  con- 
vergent by  the  refracting  media,  cross  in  the  vitreous  humour,  and 
light  up  part  {a  b)  of  the  fundus.  From  every  point  of  this  illumin- 
ated surface  rays  are  reflected  back  again  out  of  the  eye.  If  the 
latter  be  emmetropic,  the  rays  from  any  one  point  become  parallel 
on  leaving  it ;  and  some  of  these  parallel  rays,  passing  through  the 
aperture  of  the  ophthalmoscope,  fall  into  the  observer's  eye,  and, 
if  it  be  emmetropic,  are  brought  to  a  focus  on  its  retina  ;    the  rays 


30  DISEASES    OF    THE    EYE.  [chai'.  it. 

from  m  at  m\  those  from  a:  at  a;',  and  those  from  y  at  y' — and  thus 
an  image  of  the  part  x  m  y  is  formed  on  the  observer's  retina. 


Fig.  27. 

The  foregoing  method  of  examining  with  the  ophthalmoscope  is 
called  the  Direct  Method,  or  the  Examination  of  the  Upright  Image. 
The  light  should  be  placed  on  the  same  side  as  the  eye  to  be  examined, 
it  should  be  on  a  level  with  the  eye,  and  sufficiently  behind  the 
patient  to  leave  the  eye  in  the  shade.  The  observer  uses  his  left 
eye  for  the  patient's  left  eye,  and  his  right  for  the  patient's  right 
eye,  and  by  a  slight  inclination  of  his  head  he  can  get  very  close  to 
the  patient's  eye  without  coming  into  contact  with  his  face.  By 
this  method  the  various  parts  of  the  fundus  are  seen  in  their  natural 
positions,  but  much  enlarged.  The  magnification  is  about  15 
diameters  in  Em.,  more  in  M.  and  less  in  H.  ;  and  it  is  consequently 
very  valuable  for  examining  minute  details.  The  area  visible  at 
one  moment  is,  however,  small,  not  much  larger  than  the  optic  disc. 

It  is  necessary  that  the  observer  should  approach  his  eye  as 
close  as  he  can  to  the  eye  under  examination,  in  order  to  receive  as 
much  of  the  light  coming  out  of  it  as  possible,  and  also  to  obtain 
the  largest  possible  field.  The  extent  of  the  area  visible  at  one 
moment  depends  also  on  the  refraction,  being  greatest  in  H.,  and 
least  in  M. 

Moreover,  the  accommodation  both  of  the  observer's  and  of 
the  patient's  eye  must  be  at  rest,  as  otherwise  the  rays  coming 
from  the  latter  cannot  form  an  image  on  the  retina  of  the  former, 
at  least  if  both  be  emmetropic.  If  the  patient  exert  his  accommoda- 
tion, the  rays  will,  on  leaving  his  eye,  become  convergent  instead 
of  parallel,  and,  falling  into  the  observer's  eye,  will  be  brought  to  a 
focus  in  front  of  his  retina.     The  same  will  happen  if  the  observer 


OHAP.  ii.l  THE    OPHTHALMOSCOPE. 


exert  his  accommodation,  and  still  more  so  if  both  patient  and 
observer  accommodate.  The  patient's  accommodation  can  be 
relaxed  by  making  him  gaze  at  the  black  wall  behind  the  observer's 
head,  or  his  accommodation  may  be  paralysed  with  atropine.  But 
atropine  should  never  be  used  in  adults  unless  absolutely  necessary, 
owing  to  the  inconvenience  it  causes  the  patient. 

Voluntary  relaxation  of  the  accommodation  on  the  part  of  the 
observer  is  often  a  matter  of  much  difficulty  to  beginners.  With 
parallel  optic  axes  our  accommodation  is  relaxed  ;  therefore,  when 
we  want  to  relax  our  accommodation,  we  produce  parallelism  of 
our  optic  axes. .  This  sounds  easy  enough  ;  yet,  when  the  beginner 
approaches  his  eye  close  up  to  that  of  his  patient,  the  knowledge 
that  he  is  so  close  to  the  object  he  wishes  to  see  renders  the  accom- 
plishment of  this  parallelism  and  relaxation  of  accommodation 
very  difficult  to  many.  It  can  only  be  attained  by  practice,  but  it 
is  assisted  by  the  fact  that  the  eye  which  is  not  in  use  gazes  at  the 
black  wall  behind  the  patient's  head.  A  beginner  will  find  a  low 
concave  lens  behind  the  mirror  of  great  assistance. 


Fig.  28. 

The  Indirect  Method,  or  the  Examination  of  the  Inverted  Image, 

is  employed  in  order  to  obtain  a  more  general  view  of  the  fundus 
than  the  direct  method  admits  of. 

In  addition  to  the  ophthalmoscope,  a  convex  glass — the  object 
lens — {I,  Fig.  28)  of  about  14  D  is  here  used.  The  latter  is  held  at 
about  its  focal  length  from  the  eye  {E)  under  examination,  while 
the  observer  throws  the  light  from  the  mirror  through  it  into  the 
eye.  In  passing  through  I  the  rays  are  made  convergent,  and  this 
convergence  is  increased  by  the  refracting  media,  so  that  the  rays 
cross  in  the  vitreous  humour,  and  light  up  a  portion  of  the  fundus 


32  DISEASES    OF    THE    EYE.  [chap.  n. 


oculi.  From  any  points  {a  and  h)  of  this  illuminated  place  pencils 
of  rays  pass  out  again  from  the  eye,  and,  becoming  parallel,  pass 
through  I  and  are  united  by  it  at  a'  h' ;  and  thus  a  real  inverted 
image,  magnified  about  4  or  5  diameters,  is  formed  of  the  part  a  b, 
which  image  may  be  seen  by  the  observer  whose  eye  is  placed  behind 
0.  In  Em.  the  image  will  be  formed  at  the  principal  focus  of  the 
object  lens  because  the  emerging  rays  are  parallel,  in  H.  it  will  be 
found  farther  away  from  the  lens,  and  in  M.  nearer  to  the  lens  than 
in  Em.  The  stronger  the  object  lens  (/)  the  more  convergent  will 
the  rays  from  the  examined  eye  be  made  ;  and  consequently  the 
closer  must  a'  h'  be  to  each  other,  and  the  smaller  and  brighter  must 
be  the  image  formed.  The  weaker  the  object  lens  the  larger  and 
less  brilliant  is  the  image,  and  the  less  annoying  to  the  observer 
are  the  reflexes  from  its  surfaces. 

If  the  lens  be  held  at  its  focal  length  from  the  cornea,  and  then 
withdrawn  until  its  principal  focus  is  farther  from  the  eye  than 
the  anterior  focus  of  the  latter,  the  image  will  remain  unaltered  in 
size  in  Em.,  will  increase  in  size  in  M.,  and  diminish  in  H. 

In  examining  by  the  indirect  method,  the  observer  first  places 
the  upper  edge  of  the  ophthalmoscope  to  his  right  supra-orbital 
margin,  and,  taking  care  that  he  is  looking  through  the  central 
opening  of  the  mirror,  he  reflects  the  light  of  the  lamp  into  the 
patient's  eye  at  a  distance  of  about  50  cm.  A  red  glare  from  the 
fundus,  known  as  the  "  red  reflex,"  will  then  be  seen  in  the  pupil. 
Keeping  the  pupil  illuminated,  the  convex  lens  of  14  D,  held  between 
the  forefinger  and  thumb  of  the  observer's  left  hand,  is  brought 
up  in  front  of  the  patient's  eye,  and  kept  there  in  the  perpendicular 
position,  the  observer  steadying  his  hand  with  the  tip  of  the  little 
finger  on  the  patient's  forehead.  The  object  lens  is  now  removed 
just  far  enough  from  the  patient's  eye  to  cause  the  margin  of  the 
pupil  to  disappear  out  of  the  observer's  field  of  vision.  The  observer 
then  ceases  to  look  into  the  eye,  and  fixes  his  gaze  on  the  object 
lens,  when  the  inverted  image  of  the  fundus  should  at  once  be- 
come visible,  if  the  observer  accommodates  for  the  proper  distance 
— and  will  seem  to  be  situated  in  the  object  lens,  although  it  really 
is  in  the  air  somewhat  this  side  of  the  lens.  Beginners  often  fail  to 
see  the  fundus  clearly,  because  they  do  not  accommodate  sufficiently, 
and  hence  a  low  -{-  lens  placed  behind  the  sight  hole  of  the  mirror 
helps  to  bring  the  image  into  focus. 


CHAP.    II.] 


THE    OPHTHALMOSCOPE. 


33 


If,  as  is  usually  the  case,  the  ophthalmoscope  be  held  in  the 
right  hand,  it  is  better  to  place  the  light  on  the  patient's  left, 
whichever  eye  be  examined,  as  the  observer's  left  arm  will  not  then 
interfere  with  the  light  when  the  lens  is  held  up  before  the  patient's 
eye. 

The  diagram  (Fig.  29)  serves  to  illustrate  the  eifect  of  inversion 
of  the  image.  The  left  eye  is  seen  in  the  upright  image  at  a,  while 
the  same  eye  is  seen  in  the  inverted  image  at  h.  In  the  diagram 
the  two  images  are  of  the  same  size  for  the  sake  of  convenience  ; 
although,  of  course,  in  reality  the  upright  image  is  much  larger 


Fig.  29. 

than  the  inverted  image.  Moreover,  it  should  not  be  supposed 
that  nearly  the  whole  fundus  oculi,  as  here  represented,  can  be 
taken  in  at  one  view  with  the  ophthalmoscope.  The  portion  visible 
with  the  ophthalmoscope  at  one  moment,  even  in  the  inverted 
image,  is  small ;  so  that  it  is  necessary  to  examine  the  different 
regions  in  detail,  in  order  to  become  acquainted  with  the  condition 
of  the  whole  of  the  fundus. 

The  reflex  from  the  surface  of  the  cornea  gives  a  good  deal  of 
annoyance  to  every  beginner.  It  cannot  be  done  away  with,  but  is 
considerably  diminished  by  holding  the  object  lens  farther  from  the 
cornea  than  the  focal  length  of  the  lens  ;  and,  as  it  moves  in  the 
opposite  direction  to  a  motion  of  the  object  lens,  it  is  possible  to 
see  past  it. 

Reflexless  ophthalmoscopes  which  get  rid  of  the  corneal  reflex  by 
making  use  of  different  portions  of  the  patient's  pupil  for  the  entering 
and  emergent  rays  have  been  designed  by  Thorner,  and  by  Gullstrand. 
In  Gullstrand's  method  of  ophthalmoscopy  a  Nernst  lamp  with  a  fine 
vertical  slit  acts  as  the  source  of  light.  It  ensures  a  brilliant  illumination 
and  shows  up  fine  details  with  great  definition. 

3 


34  DISEASES    OF    THE    EYE.  [chap.  n. 


The  reflections  from  the  convex  object-lens  are  also  extremely 
annoying,  but  may  be  removed  to  a  great  extent  from  the  line  of 
sight  by  a  slight  rotation  of  the  lens  on  its  axis.  If  a  very  high 
object-lens  (say  +  20  D)  be  used,  the  reflections  from  it  are  more 
disturbing  than  from  a  lower  number  (say  +  14  D). 

To  examine  the  Opic  Nerve  (or  Optic  Disc)  the  observer  sits  in 
front  of  the  patient,  and  directs  him  to  turn  his  eye  somewhat 
to  the  nasal  side,  and  slightly  upwards  ;  because  the  optic  nerves, 
diverging  from  the  chiasma,  enter  the  back  of  the  eye  a  little  to  the 
inner  side  of  the  posterior  pole,  and  the  papilla,  or  disc,  comes  to 
be  situated  about  15°  to  the  inner  side  of  the  posterior  pole  of  the 
eye,  and  about  3°  above  it.  For  instance,  if  the  left  eye  be  examined 
the  patient  is  to  direct  his  gaze,  (without  turning  his  head,)  to  his 
right  and  a  little  upwards,  say  towards  the  observer's  left  ear.  It 
is  well  always  to  seek  out  the  optic  papilla  in  the  first  instance, 
not  only  because  it  is  such  an  important  part  of  the  fundus  oculi, 
but  also  because,  examining  from  it  towards  the  periphery,  we  are 
the  better  able  to  determine  the  locality  of  any  pathological  alter- 
ation. 

Should  the  patient  not  direct  his  gaze  in  such  a  way  as  to  enable 
the  observer  to  see  the  optic  disc  or  other  desired  region,  it  may  be 
brought  into  view  either  by  a  motion  of  the  observer's  head  in  the 
opposite  direction,  or  by  a  motion  of  the  object-lens  in  the  same 
direction,  or  by  a  combination  of  these  measures.  When  the  disc 
is  opposite  the  observer's  eye,  the  pupillary  reflex  is  seen  to  become 
paler  or  even  white,  and  the  corneal  image  of  the  light  will  occupy 
the  junction  of  the  middle  and  outer  thirds  of  the  horizontal  dia- 
meter of  the  cornea. 

The  Macula  Lutea  should  then  be  examined.  It  may  be  seen 
by  directing  the  patient  to  look  straight  at  the  hole  of  the  ophthal- 
moscopic mirror,  for  it  will  then  correspond  with  the  macula  lutea 
of  the  observer's  eye.  It  is  more  readily  seen  in  the  inverted  than 
in  the  upright  image  ;  but  its  examination  is  often  very  difficult, 
owing  to  contraction  of  the  pupil  produced  by  the  strong  light  falling 
on  so  sensitive  a  portion  of  the  retina,  and  by  the  reflections  from 
the  surfaces  of  the  cornea  and  crystalline  lens,  which  fill  the  area 
of  this  contracted  pupil.  It  is  therefore  a  better  plan  to  direct  the 
patient  to  look  somewhat  to  the  side  of  the  eye  under  examination 
— e.g.,  to  the  right  side  of  the  observer's  forehead,  if  the  left  eye 


THE    OPHTHALMOSCOPE. 


35 


be  under  examination,  and  then  by  motions  of  the  object-lens  to 
bring  the  macula  lutea  into  view. 

After  this  the  Periphery  of  the  Fundus  in  every  direction  is 
to  be  examined  by  making  the  patient  look  upwards,  downwards, 
to  the  right,  to  the  left,  etc. 

The  indirect  method  possesses  the  following  advantages  : — 
It  gives  a  large  field  in  which  it  is  possible  rapidly  to  locate  the 
position  of  a  lesion,  it  can  be  used  no  .matter  what  the  error  of 
refraction  may  be,  and  it  is  not  necessary  to  approach  close  to 
the  patient's  face. 

Detection  of  Opacities  in  the  Refractive  Media  by  the  Ophthal- 
moscope.— Opacities  in  the  refractive  media  can  be  best  detected 
with  the  ophthalmoscope  by  the  direct  method.  All  opacities  look 
black  in  the  red  pupil,  because  they  intercept  the  light  returning 
from  the  illuminated  fundus. 


Fig.  30. — Apparent  position  in  the  pupil  of  opacities  of  the  media 
when  the  obser\^er  alters  his  point  of  view. 

Two  methods  of  examination  are  employed.  In  the  first  the 
eye  is  examined  at  a  distance  of  about  30  cm.  ;  and  the  patient 
is  directed  to  move  the  eye  in  different  directions,  in  order  to  bring 
any  peripheral  opacities  into  view  and  also  to  localise  them.  Movable 
opacities  must  lie  in  the  fluid  media.  They  are  almost  always  in  the 
vitreous  humour,  and  can  be  seen  to  float  to  and  fro  when  the  eye 
comes  to  rest.  Fixed  opacities  move  with  the  eye,  and  lie  in  the 
cornea  or  lens,  or  sometimes  in  the  vitreous.  Fig.  30  illustrates 
the  apparent  displacement  of  an  opacity  in  the  pupil  according 
to  its  position  in  the  media.  When  the  eye  of  the  observer  0  is 
opposite  the  pupil,  the  opacities  1  to  4  lying  on  the  axis  appear  as 
one  point  in  the  centre  of  the  patient's  pupil  (shown  by  P).     When 


36  DISEASES    OF    THE    EYE.  [chap.  ii. 


the  eye  is  rotated  upwards,  or  the  observer  moves  downwards,  2, 
which  is  on  the  anterior  surface  of  the  lens,  in  the  plane  of  the 
pupil,  will  still  appear  to  be  in  the  same  position,  while  1,  seen  in  the 
direction  a  b,  will  seem  to  be  displaced  upwards,  and  3  and  4  down- 
wards, the  relative  positions  being  as  indicated  in  the  circle  at  P'. 

The  second  and  more  delicate  method  of  detecting  opacities 
consists  in  examining  the  eye  close  up  with  a  convex  lens  of  20  D, 
behind  the  sight  hole  of  the  mirror.  Very  fine  opacities  can  be 
seen  in  this  way,  such  as  minute  punctate  deposits  on  the  cornea. 
Focussing  for  different  levels  can  be  accomplished  by  approaching 
closer  for  deeper  opacities,  or  by  using  gradually  weaker  lenses.  Too 
strong  an  illumination  interferes  with  the  perception  of  faint 
opacities,  hence  the  plane  mirror  serves  better  for  this  purpose  than 
the  concave. 

Prominent  portions  of  the  interior  of  the  eye,  such  as  a  detached 
retina  or  an  intra-ocular  tumour,  can  also  be  detected,  and  examined 
in  detail,  by  the  direct  method  at  a  distance,  or  close  up.  The 
estimation  of  the  refraction  by  the  ophthalmoscope  will  be  dealt 
with  in  chap.  xvi. 

The  electric  ophthalmoscope,  in  which  a  small  electric  bulb  acts  as  the 
source  of  light,  is  a  very  useful  instrument,  especially  in  the  examination 
by  the  erect  image.  The  Marple-Morton  model,  which  has  a  U  shaped 
mirror,  is  the  best.  In  its  most  recent  form  the  current  is  supplied  by  a 
small  dry  cell  contained  in  the  handle  of  the  ophthalmoscope,  which  is 
also  provided  with  a  rheostat  for  varying  the  degree  of  illumination. 

THE  NORMAL  FUNDUS  OCULI  AS  SEEN 
WITH  THE  OPHTHALMOSCOPE. 

The  Optic  Disc  or  Optic  Papilla. — This  is  the  first  object  to  be 
sought  for  by  the  observer.  It  presents  the  appearance  of  a  pale 
pink  disc,  somewhat  oval  in  shape,  its  long  axis  being  vertical. 
Occasionally  the  long  axis  lies  horizontally,  and  sometimes  the 
papilla  is  circular.  The  papilla  is  generally  surrounded  by  a  white 
ring,  more  or  less  complete,  called  the  sclerotic  ring,  and  often,  out- 
side this  again,  by  a  more  or  less  complete  black  line,  the  chorioidal 
ring  (Plate  I.  Fig.  1).  The  sclerotic  ring  is  due  to  the  chorioidal 
margin  not  coming  quite  up  to  the  margin  of  the  papilla,  the  fora- 
men in  the  chorioid  for  the  passage  of  the  optic  nerve  fibres  being 
somewhat  larger  than  that  in  the  sclerotic,   and  consequently  a 


# 


PLATE    I 

{To  face  page  36) 

Yjg.  1. — The  optic  disc  shows  a  small  central  physiological  cup,  a  pale 
scleral  ring,  and  an  outer  pigmented  or  chorioidal  ring.  Close  to  the 
latter  is  a  cilio-retinal  vessel.  The  macula  lutea,  of  a  deeper  red 
than  the  rest  of  the  fundus,  is  surrounded  by  a  delicate  oval  light- 
reflex.  The  bright  spot  in  the  centre  of  the  macula  is  the  fovea 
centralis. 

YiQ.  2. — The  patch  of  opaque  nerve-fibres  is  of  a  brilliant  white  ;  it  is 
prolonged  in  the  direction  of  some  of  the  vessels,  and  presents  a 
characteristic  finely  striated  border.  Note  the  dark  colour  of  the 
disc,  which  is  chiefly  a  result  of  contrast.  The  vision  was  the  same  as 
in  the  unaffected  eye. 


Plate  I. 


Fig.   1.     Normal  Disc  and  Macula. 


L.W. 


Fig.  2.     Opaque  Nerve  Fibres. 


CHAP.  II.]  THE    OPHTHALMOSCOPE.  37 

narrow  edging  of  the  white  sclerotic  is  exposed.  The  chorioidal 
ring  is  the  result  of  a  hyper-development  of  pigment  at  the  margin 
of  the  chorioidal  foramen. 

The  complexion  of  the  optic  disc  results  from  the  pink  hue 
derived  from  its  fine  capillary  vessels,  combined  with  the  whiteness 
of  the  lamina  cribrosa,  and  the  bluish  shade  of  the  nerve  fibres. 
It  is  frequently  not  equal  all  over,  but  is  paler  on  the  outer  side, 
where  the  margin  is  more  defined,  and  where  the  nerve  fibres  are 
fewer  than  on  the  inner  side.  The  apparent  colour  of  the  papilla 
depends  also  upon  the  complexion  of  the  rest  of  the  fundus.  If 
the  latter  be  highly  pigmented,  the  papilla  appears  pale  in  contrast ; 
while,  if  there  be  but  little  pigment  in  the  chorioid,  the  papilla  may 
appear  very  pink.  The  complexion  of  every  normal  papilla  is 
not  identical,  and  care  must  be  taken  not  to  make  the  diagnosis 
"  Hyperaemia  of  the  papilla  "  where  merely  a  high  physiological 
complexion  is  present.  The  upper  and  lower  margins  of  the  papilla 
are  often,  especially  in  young  people,  a  little  indistinct,  and  show  a 
delicate  striation  by  the  direct  method  of  examination.  This  may 
be  greatly  exaggerated  in  hypermetropes,  and  has  in  them  been 
sometimes  erroneously  taken  for  optic  neuritis. 

A  physiological  excavation  of  the  optic  papilla  is  often  met  with 
as  a  white  depressed  area  (Plate  I.  Fig.  1)  either  on  the  temporal 
side  or  in  the  centre  of  the  papilla,  and  can  be  recognised  by  the 
parallax  1  which  may  be  produced,  and  by  its  colour.  When  the 
excavation  is  very  deep,  one  may  sometimes  observe  the  lamina 
cribrosa  in  the  form  of  grey  spots  (the  nerve  fibres)  surrounded  by 
white  lines  (the  fibrous  tissue  of  the  lamina). 

A  physiological  excavation  differs  from  a  pathological  excavation, 
in  that  it  does  not  reach  the  margin  of  the  papilla  all  round.  It  is 
caused  by  the  crowding  over  of  the  nerve  fibres  to  the  inner  side  of 
the  papilla.  Yet  sometimes,  a  healthy  optic  papilla  will  be  met 
with,  in  which  the  excavation  apparently  reaches  the  margin  all 
round. 

The  Normal  Retina  is  so  translucent  that  it  cannot  be  seen, 
the  red  reflex  being  due  to  the  chorioidal  vessels.  At  most,  a  shim- 
mering reflection  of  shot-silk  appearance  is  obtained  from  it,  par- 
ticularly about  the  region  of  the  yellow  spot  (Plate  I.  Fig.  1)  and 

^  For  explanation  of  the  parallax  see  chap.  ix. 


38  DISEASES    OF    THE    EYE,  [chap.  n. 

along  the  vessels,  but  also  towards  the  equator  of  the  eye,  and 
especially  in  dark  eyes,  and  in  young  people. 

A  peculiar,  but  physiological,  appearance  known  as  opaque  nerve 
fibres  (Plate  I.  Fig.  2)  is  occasionally  seen.  It  is  produced  by  some 
of  the  nerve  fibres  forming  the  internal  layer  of  the  retina  regaining 
the  medullary  sheath  on  the  distal  aspect  of  the  lamina  cribrosa, 
or  near  the  margin  of  the  papilla,  which  they  had  lost  in  the  optic 
nerve  just  before  entering  the  lamina  cribrosa  ;  the  rule  being 
that  the  nerve  fibres  lose  their  medullary  sheath  at  the  latter  place 
definitely,  and  enter  the  retina  as  axis  cylinders  only,  and  hence 
are  quite  translucent.  But  in  these  cases  the  nerve  fibres  reflect 
the  light  strongly,  giving  the  effect  of  an  intensely  white  patch,  com- 
mencing at  the  disc,  extending  more  or  less  into  the  surrounding 
retina,  and  terminating  in  a  brushlike  extremity.  In  such  cases 
the  optic  papilla  appears  to  be  darker  than  normal,  partly  from 
contrast.     This  appearance  is  constant  in  the  rabbit's  eye. 

The  Macula  Lutea  is  generally  seen  as  a  bright  oval  ring  with  its 
long  axis  horizontal,  this  ring  being  probably  a  reflex  from  the 
surface  of  the  retina  (Plate  I.  Fig.  1).  It  is  remarkable  that  this 
halo  is  not  visible  with  the  direct  method  of  examination — a  fact  due 
probably  to  the  illumination  being  much  weaker  than  with  the 
indirect  method.  The  area  inside  the  ring  is  of  a  deeper  red  than 
the  rest  of  the  fundus,  and  at  its  very  centre  there  is  an  intensely 
bright  point,  the  fovea  centralis.  The  ring  is  not  seen  in  old  people. 
The  macula  lutea  is  situated  to  the  temporal  side  of  the  optic  disc, 
about  two  disc  diameters  away  from  it,  and  slightly  above  the  lower 
margin  of  the  disc. 

The  General  Fundus  Oculi  surrounding  the  optic  papilla  and 
macula  lutea  varies  a  good  deal  in  appearance,  according  to  the 
amount  of  pigment  contained  in  the  chorioid  and  in  the  pigment- 
epithelium  layer  of  the  retina.  1.  If  there  be  an  abundant  supply 
of  pigment  in  each  of  these  positions,  the  chorioidal  vessels  are 
greatly  hidden  from  view,  and  the  effect  is  that  of  a  very  dark  red 
fundus.  2.  If  there  be  but  little  pigment  in  the  pigment-epithelium 
layer,  the  larger  chorioidal  vessels  may  be  visible,  and  the  fundus 
may  appear  to  be  divided  up  into  dark  islands  surrounded  by  red 
lines.  3.  If  the  individual  be  a  blonde,  there  is  little  pigment  either 
in  the  pigment-epithelium  layer  or  in  the  chorioid,  and  the  fundus 
is  seen   of  a,  very  l)right  red  colour,   the   chorioidal  vessels  down 


CHAP.    II.] 


THE    OPHTHALMOSCOPE. 


39 


to  their  fine  ramifications  being  discernible.  In  albinos  even  the 
chorioidal  capillaries  may  be  seen.  The  chorioidal  vessels  are  flat, 
they  vary  much  in  size,  and  anastomose  freely  (see  Plate  IV.  Fig.  1, 
and  Plate  IX.  Fig.  2). 

The  Retinal  Vessels. — The  arteries  are  recognised  as  thin  bright 
red  lines  running  a  rather  straight  course,  in  the  centre  of  each  of 
which  is  a  light-streak.  As  to  the  cause  of  this  light-streak  there 
is  considerable  divergence  of  opinion.     Some  attribute  it  to  reflection 


Fig.  31.   {Groefe  and  Scemisch.) 


a.n.s.,  Art.  nas.  sup.  ;  aji.i.,  Art.  nas.  inf.  ;  a.t.s.,  a.t.i.,  A.  temp.  sup.  and  inf.  ;  v.n.s.,  v.n.i. 
Ven.  nas.  sup.  and  inf.  ;  v.t.s.,v.t.i.,\en.  temp.  sup.  and  inf.  ;  a.m.c.,v.m.e.,^^vt.  and  ven.  median 
a.m.,  v.ni..  Art.  and  ven.  macularis. 


from  the  coats  of  the  vessel,  or  from  the  surface  of  the  blood  column  ; 
while  others  believe  that  the  light  is  reflected  from  the  fundus 
through  the  vessel,  which  then  acts  as  a  very  strong  cylindrical 
lens.  This  light-streak  divides  the  vessel  into  two  red  lines.  The 
vems  are  darker,  wider,  and  more  tortuous  in  their  course  than  the 
arteries,  and,  their  coats  not  being  so  tense,  the  light-streak  on  them 
is  very  much  fainter. 


40  DISEASES    OF    THE    EYE.  [chap.  ii. 

On  reaching  the  level  of  the  nerve-fibre  layer  of  the  retina  the 
central  artery  and  vein  divide  into  a  principal  upper  and  lower 
branch.  This  first  branching  often  takes  place  earlier  in  the  vein 
than  in  the  artery,  and  the  former  may  even  branch  before  appearing 
on  the  papilla,  as  in  Fig.  31.  The  second  branching  may  take 
place  in  the  nerve  itself ;  and  when  this  occurs  it  will  appear  as 
though  four  arteries  and  four  veins  sprang  from  the  optic  papilla  ; 
but  more  usually  this  branching  occurs  on  the  papilla,  as  in  Fig.  31. 
The  vessels  produced  by  this  second  branching  pass  respectively 
towards  the  median  and  temporal  side  of  the  retina,  and  are  termed 
the  Art.  and  Ven.  nasalis  and  temporalis  sup.  and  inf.  {vide  Fig.  31). 
The  temporal  branches  run  in  a  radial  direction  towards  the  anterior 
part  of  the  retina.  A  small  horizontal  branch,  the  Art.  and  Ven. 
mediana,  from  the  first  principal  branches  is  found  passing  towards 
the  nasal  side  of  the  retina.  The  temporal  branches  do  not  run  in 
a  horizontal  direction,  but  make  a  detour  round  the  macula  lutea, 
sending  fine  branches  towards  the  latter.  Two  or  three  minute 
vessels  from  principal  branches  run  directly  from  the  papilla  toward 
the  macula  lutea,  and  around  the  macula  lutea  a  circle  of  very 
fine  capillary  vessels  is  formed  which  cannot  be  distinguished  with 
the  ophthalmoscope  ;  but  no  vessels  run  to,  or  cross  over,  the 
fovea  centralis  itself.  The  retinal  arteries  do  not  anastomose, 
nor  do  the  larger  retinal  veins.  The  small  retinal  veins  have  some 
slight  anastomoses  near  the  ora  serrata.  Occasionally,  a  vessel 
emerges  near  the  margin  of  the  disc,  usually  at  the  temporal  side. 
It  arises  from  the  ciliary  vessels,  and  is  hence  called  a  cilio-retinal 
vessel  (Plate  I.  Fig.  1). 

No  pulsation  of  the  arteries  is  observable  in  the  normal  eye. 
In  the  larger  veins  near  or  on  the  optic  papilla,  or  more  usually 
just  at  their  point  of  exit,  a  pulsation  may  sometimes  be  seen. 
This  venous  puliation  is  due  to  the  following  sequence  of  events  ; 
systole  of  the  heart ;  diastole  of,  and  high  tension  in,  the  retinal 
arteries  ;  consequent  increased  pressure  in  the  vitreous  humour  ; 
communication  of  this  to  the  outside  of  the  walls  of  the  retinal 
veins,  impeding  the  flow  of  blood  through  them,  especially  in  their 
larger  trunks,  which  offer  little  resistance,  or  at  their  exit  from  the 
eye,  where  the  blood  pressure  is  lowest ;  and  in  this  way  the  veins 
are  emptied — the  blood  gradually  coming  on  from  the  capillaries 
overcomes  the  resistance,  and  the  veins  are  for  a  moment  refilled. 


CHAP.  II.]  THE    OPHTHALMOSCOPE.  41 

The  phenomenon  can  be  most  readily  observed,  if  the  normal  tension 
of  the  globe  be  increased  by  gentle  pressure  with  the  finger  during 
the  ophthalmoscopic  examination.  By  increasing  the  pressure  the 
arteries  also  can  be  made  to  pulsate  even  in  a  normal  eye,  but 
such  a  degree  of  pressure  is  dangerous. 


CHAPTER    III. 

DISEASES   OF  THE    CONJUNCTIVA. 

The  Conjunctiva,  or  Conjunctival  Sac,  whicli  is  a  mucous  membrane, 
may  for  descriptive  purposes  be  divided  into  three  portions  :  the 
palpebral,  which  forms  a  smooth  lining  for  the  inner  surface  of  the 
eyelids  ;  the  bulbar,  loosely  covering  the  sclerotic  ;  and  the  retro- 
tarsal  folds,  uniting  ^these  two,  which  form  the  sulcus  or  fornix, 
upper  and  lower.  When  the  bulbar  conjunctiva  reaches  the  margin 
of  the  cornea  it  overlaps  the  latter  sHghtly,  and  this  overlapping 
portion  is  known  as  the  limbus  conjunctivae,  or  cornese.  At  the  inner 
angle  or  canthus  there  is  a  vertical  crescentic  fold,  the  plica  semi- 
lunaris, on  the  nasal  side  of  which  is  a  rounded  mass  of  modified  skin 
called  the  caruncle. 

On  the  palpebral  surface  of  the  upper  lid  close  to,  and  running 
parallel  to  the  margin,  is  a  shallow  groove,  called  the  subtarsal  sulcus. 
Some  adenoid  tissue  exists  in  the  fornices  of  the  normal  conjunctiva, 
and  follicles  are  sometimes  found,  the  latter  being  probably  due  to 
the  constant  irritation  to  which  the  conjunctiva  is  exposed.  The 
conjunctiva  is  lubricated  by  the  secretion  from  the  glands  and 
conjunctival  epithelium.  The  lacrimal  fluid,  which  has  only  a  very 
slight  bactericidal  action,  merely  exercises  a  mechanical  effect  which 
consists  in  the  washing  away  of  foreign  particles. 

The  Examination  of  the  Conjunctiva.— Simple  inspection  in  good 
diffused  daylight,  the  patient  facing  the  window,  is  better  than 
artificial  illumination.  The  whole  of  the  mucous  membrane  should 
be  examined,  and  for  this  purpose  the  lids  must  be  everted.  The 
eversion  of  the  lower  lid  is  a  simple  matter,  but  a  certain  amount  of 
practice  is  required  in  the  case  of  the  upper  lid. 

Eversio7i  of  the  upper  lid. — The  surgeon  should  face  the  patient 
and  direct  him  to  look  down  and  to  continue  looking  down,  in  order 
to  render  the  upper  edge  of  the  tarsus  accessible.     The  point  of 

42 


CHAP.    III. 


THE    CONJUNCTIVA. 


43 


the  thumb  of  one  hand  is  then  placed  on  the  outer  surface  of  the 
lid,  just  above  the  tarsus,    and  with  it  the  skin  is  drawn  a  little 


Fig.   32. — First  steps  in  eversion 
of  upper  lid. 


Fici.    33. — Everted  lids  held  in 
position  with  one  hand. 


upwards  and  backwards  ;  this  causes  the  margin  of  the  lid  to  start 
forwards.  The  eyelashes  (or  the  margin  of  the  Hd)  are  then  taken 
between  the  thumb  and  forefinger  of  the  other  hand  (Fig.  32)  and 


Fig.  34. — Method  of  examining  a  child's  eye. 

raised  upwards,  while  the  thumb  above  is  depressed.  The  thumb 
which  acts  as  the  depressor  should  not  be  taken  away  too  soon,  a 
mistake  often  made  by  beginners,  and  it  is  better  to  slide  it  away 


44 


DISEASES    OF    THE    EYE. 


[chap.    III. 


sideways.     In  case  of  failure  a  probe  or  glass  rod  can  be  used  instead 
of  the  thumb.     When  everted,  the  lids  can  be  retained  in  position 
by  one  hand  (Fig.  33),    while    ap- 
plications   are    being    made  to  the 
conjunctiva. 

The  method  of  examining  the  con- 
junctiva and  cornea  in  infants  and 
children  is  shown  in  Fig.  34.  The 
head  is  firmly  held  between  the 
surgeon's  knees.  The  conjunctiva 
is  easily  inspected,  as  the  lids  be- 
come everted  on  merely  attempting 
to  open  the  eye  by  pulling  on  the 
skin  near  the  lid  margins.  In  order 
to  examine  the  cornea,  the  lids  must 
not  be  allowed  to  become  everted, 
but  must  be  separated  with  the  points  of  the  fingers  placed  on  the 
ciliary  margins  as  shown  in  Fig.  35.  The  cornea  at  first  rotates 
under  the  upper  lid,  but  soon  comes  down  into  view.  Care  must  be 
taken  to  avoid  injuring  the  cornea  with  the  finger  nails,  or  using  too 
great  pressure  on  the  eye,  which  might  rupture  a  corneal  ulcer. 
The  surgeon  too  must  beware  lest  retained  secretion  should  spurt 
up  into  his  own  eyes. 

The  normal  conjunctival  surface  of  the  upper  lid  is  smooth. 


Fig.  35.— Method  of  exposing 
a  child's  eye. 


Fig.    36. — Examination   of   retro- 
tarsal  folds  of  upper  lid. 


Fig.  37. — Exposure  of  upper 
fornix  ;  lid  everted  and 
raised  with  retractor. 


yellowish-pink  in  colour,   and  the  conjunctiva  is  adherent  to  the 
tai'siis      The  small  l)i'anches  of  the  tarsal  arches  can  be  seen  runninjj; 


Plate  II. 


Fig.  I.     Conjunctival  Congestion.  Fig.  2.     Ciliary  Congestion  (Iritis). 


Fig.  3.     Ciliary  Congestion 
(Phlyctenular). 


Pig,  4.     Ciliary  Congestion 
(Glaucoma). 


Fig.  o.     Congestion  in  Scleritis.  Fio.   0.     Ecchymosis  of  Conjunctiva. 


PLATE    II 

(To  face  page  4.1) 

TYPES    OF    CONGESTION 

Fig.  1. — Conjunctival  congestion  associated  with  catarrhal  conjunctivitis. 
The  vessels  are  bright  red,  tortuous,  and  easily  seeii.  The  congestion 
is  greatest  towards  the  periphery. 

Fig,  2. — The  delicate  pink  zone  of  ciliary  congestion  immediately  sur- 
rounds the  cornea,  and  is  composed  of  very  minute  vessels  which 
are  not  easily  seen  separately.  A  pointed  posterior  synechia  renders 
the  pupil  irregular,  and  on  the  iris  is  a  reddish  yellow  tumour  (a 
gumma). 

Fig.  3. — These  small  patches  of  ciliary  congestion  precede  or  follow  the 
development  of  marginal  phlyctens. 

Fig.  4. — The  ciliary  congestion  here  consists  of  a  fine  venous  reticulum. 
Note  the  few  large  tortuous  veins,  and  the  dilated  and  greenish  pupil. 

Fig.  5. — Note  the  patch  of  deep  violet  congestion,  with  slight  diffuse 
swelling,  the  discoloration  of  the  sclerotic  above  and  below,  and  the 
irregular  outline  of  the  cornea  due  to  the  encroachment  of  '  sclero- 
tising   opacities.' 

Fig.  C. — The  appearance  of  the  effusion  of  blood  under  the  conjunctiva 
is  easily  distinguished  from  a  localised  congestion. 


■■•■■-.;!•      >■  :     I"  IM  lilUi,    ■ 

'  oi  9ub  aenioo  edi  lo 


CHAP,  iii.l  THE    CONJUNCTIVA.  45 

in  a  vertical  direction,  and  the  Meibomian  glands  appear  as  yellowish 
or  grey  lines  at  right  angles  to  the  ciliary  margin  of  the  lid.  The 
stndent  should  note  the  appearance  and  thickness  of  the  edge  of 
the  normal  tarsus  when  everted.  Figs.  36  and  37  illustrate  the 
method  of  inspecting  the  retro-tarsal  folds  and  fornix.  The  double 
eversion  (Fig.  37)  is  necessary  in  cases  of  suspected  foreign  bodies  in 
the  fornix. 

The  blood-vessels  of  the  conjunctiva  consist  of  the  posterior 
conjunctival  vessels  derived  from  the  palpebral  vessels,  and  the 
anterior  conjunctival  vessels  which  pass  backwards  from  the  anterior 
ciliary  vessels.  In  general  affections  of  the  conjunctiva  the  former 
are  chiefly  involved.  Engorgement  of  the  vessels  of  the  conjunc- 
tiva is  known  as  conjunctival  congestion  (Plate  II.  Fig.  1),  in  order 
to  distinguish  it  from  ciliary  congestion,  which  accompanies  diseases 
of  the  cornea  and  iris.  It  is  bright  red  in  colour,  most  marked 
towards  the  fornix,  and  is  formed  by  a  network  of  large,  tortuous, 
superficial  vessels,  which  move  with  the  conjunctiva.  Ciliary  con- 
gestion (Plate  II.  Fig.  2)  on  the  other  hand  is  limited  to  the  cir- 
cumcorneal  area,  and  diminishes  towards  the  periphery.  It  is  due 
to  engorgement  of  the  episcleral  branches  of  the  anterior  ciliary 
vessels.  It  is  pink  or  violet  in  colour,  and  is  composed  of  minute 
straight  radiating  vessels,  which  are  frequently  indistinguishable 
to  the  naked  eye  as  separate  vessels.  They  are  situated  under  the 
conjunctiva,  and  cannot  be  moved  with  it.  In  severe  inflammations 
of  the  eyeball,  such  as  a  purulent  ulcer  of  the  cornea,  these  two 
forms  of  congestion  are  frequently  present  together. 

Hyperaemia  of  the  Conjunctiva.— In  this  condition  the  blood- 
vessels of  the  palpebral  conjunctiva  are  especially  engaged.  A 
slight  serous  exudation  sometimes  takes  place,  which  may  raise  the 
conjunctiva  around  the  cornea,  a  condition  known  as  chemosis 
{xatiw,  to  gape  open).  Yet  there  is  not  any  abnormal  discharge 
from  the  conjunctiva,  and  herein  lies  the  chief  clinical  difference 
between  this  affection  and  simple  conjunctivitis.  Of  course  a 
hyperaemia  may  be  the  earliest  stage  of  a  conjunctival  in- 
flammation. 

Causes. — Foreign  bodies.  Dust,  foul  air,  or  air  loaded  with 
tobacco-smoke.  Alcoholic  excesses.  Accommodative  asthenopia. 
Stenosis  lacrimalis,  and  other  forms  of  lacrimal  obstruction.  The 
use  of  unsuitable  spectacles,  or  the  use  of  the  eyes  for  near  work 


46  DISEASES    OF    THE    EYE.  [chap.  m. 


without  spectacles,  "wlien  the  conditiou  of  the  accommodation  {e.g. 
hypermetropia,  presbyopia)  requires  them. 

Symptoms. — Tlie  eyes  are  irritable.  There  is  lacrimation  and 
photophobia,  with  hot,  burning  sensations,  and  sensations  as  of 
a  foreign  body  in  the  eye,  and  the  eyelids  feel  heavy.  All  these 
symptoms  are  aggravated  in  artificial  light. 

Treatmeyit. — In  addition  to  the  removal  of  the  cause,  the  in- 
stillation of  mild  astringents  or  of  a  drop  of  tincture  of  opium  and 
distilled  water  in  equal  parts  morning  and  evening  will  be  found 
beneficial.  Adrenaline  has  no  permanent  effect  on  the  hypersemia. 
The  eyes  should  be  protected  from  the  glare  of  light  by  dark  glasses, 
and  out-of-door  exercise  is  to  be  recommended. 

Conjunctivitis  in  general. — The  term  Ophthalmia  is  commonly 
used  as  a  synonym  of  Conjunctivitis, ^  which  differs  from  mere 
hypersemia  in  the  presence  of  abnormal  secretion.  Apart  from 
mechanical  or  chemical  irritation,  inflammation  of  the  conjunctiva 
is  almost  always  caused  by  micro-organisms  gaining  access  to  the 
conjunctival  sac  ;  or  perhaps,  in  some  cases,  by  the  sudden  develop- 
ment, under  favourable  conditions,  of  those  which  had  been  already 
present  in  a  latent  condition.  They  can  easily  be  detected  in  the 
discharge,  except  sometimes  in  the  rare  cases  of  metastatic  or  endo- 
genous origin,  and  are  the  cause  of  its  infectious  nature.  Sporadic 
cases  are  very  common,  but  the  disease  frequently  spreads  through 
the  members  of  a  household,  or  occurs  as  an  epidemic.  Infection 
takes  place  by  the  direct  transference  of  the  secretion  from  person  to 
person,  or  indirectly  by  a  common  use  of  the  same  articles  by  different 
people.  Inflammations  of  the  conjunctiva  are  met  with  in  patients 
of  all  ages,  and  at  all  seasons  of  the  year  ;  but  some  forms  are  more 
common  in  the  spring  and  autumn.  The  palpebral  conjunctiva 
is  often  affected  when  the  bulbar  portion  remains  normal,  and  the 
conjunctiva  of  the  lower  lid  is  more  frequently  attacked  than  that 
of  the  upper  lid. 

Differential  Diagnosis. — The  milder  forms  of  conjunctivitis  are 
apt  to  be  mistaken,  by  those  who  are  inexperienced,  for  iritis  and 
vice  versa,  but  with  care  there  should  be  no  difficulty  in  distinguish- 

1  Blepharitis  is  sometimes  called  Ophthalmia  tarsi,  and  to  this  there 
can  be  little  objection,  but  the  name  Sympathetic  Ophthalmia  is  liable 
to  mislead,  as  this  disease  has  nothing  to  do  with  the  conjunctiva,  being 
in  fact  an  inflammation  of  the  uveal  tract. 


OHAP.  TIT.]  THE    CONJUNCTIVA.  47 


ing  between  the  two  affections.  Conjunctivitis  is  accompanied  by 
conjunctival  congestion,  the  secretion  is  muco-purulent,  and  if 
not  in  sufficient  quantity  to  be  detected  in  the  conjunctival  sac, 
its  presence  is  indicated  by  the  fact  that  the  Hds  are  gummed  to- 
gether in  the  mornings.  The  pain  is  superficial  and  limited  to  the 
eye  itself  (sensation  of  foreign  body,  heat,  itching).  Vision  is  not 
aflfected,  except  temporarily  by  secretion  on  the  surface  of  the 
cornea,  which  is  easily  removed  by  rubbing  the  lids  over  the  eye. 
Iritis,  on  the  other  hand,  is  recognised  by  the  presence  of  ciliary 
congestion,  lacrimation  instead  of  a  sticky  secretion,  and  by  the 
character  of  the  pain,  which  is  neuralgic  and  circumorbital.  More- 
over, the  vision  becomes  impaired  at  a  very  early  stage  of  the  disease. 
The  ultimate  diagnosis  rests  of  course  on  the  appearance  of  the  iris 
and  on  the  effect  of  atropine  (see  chap.  vii.). 

Varieties  of  Conjunctivitis. — Although  an  accurate  diagnosis 
of  the  different  forms  of  conjunctivitis  depends  on  the  discovery 
of  the  particular  micro-organism  in  each  case,  nevertheless  the  usual 
classification,  which  is  based  on  clinical  appearances,  must  for  the 
present  be  adhered  to,  partly  because  these  appearances  are  suffi- 
cient in  most  cases  to  indicate  the  line  of  treatment  required,  but 
chiefly  because  the  type  of  inflammation  excited  by  a  given  microbe 
is  not  sufficiently  constant.  In  the  majority  of  cases  no  doubt 
a  definite  group  of  symptoms  is  associated  with  a  particular  micro- 
organism, but  occasionally  the  reaction  takes  a  different  form.^ 
Again,  one  and  the  same  clinical  picture  may  be  produced  by  different 
micro-organisms.  In  exceptional  cases,  too,  a  mixed  infection 
may  take  place. 

From  a  clinical  point  of  view,  then,  conjunctivitis  is  divided 
into  different  varieties,  depending  on  the  nature  of  the  discharge, 
the  pathological  changes  in  the  tissues,  and  the  severity  of  the 
symptoms.  In  Catarrhal  Conjunctivitis,  which  may  be  acute  or 
chronic,  the  discharge  is  muco-purulent  in  character,  whereas  in 
Purulent  Conjunctivitis  pure  pus  is  secreted.  The  discharge  becomes 
fibrinous  and  coagulates  to  form  a  membrane,  lying  on  the  surface 
of  the  conjunctiva,  in  the  so-called  Croupous  variety,  or  it  extends 
into  the  substance  of  the  tissues  in  the  Diphtheritic  form.     In  some 

^  This  may  be  due  to  altered  conditions,  such  as  differences  in  the 
resistance  of  the  tissues  or  blood,  or  to  variations  in  the  degree  of  virulence 
of  the  microbe. 


48  DISEASES    OF    THE    EYE.  [chap.  hi. 


cases  (Spring  Catarrh)  the  discliarge  contains  kirge  numbers  of 
eosinopliil  cells.  All  inflammations  of  the  conjunctiva  are  accom- 
panied by  more  or  less  increase  of  the  normal  lymphoid  tissue, 
which  is  of  a  diffuse  character,  l)ut  in  certain  cases  lymphoid  masses 
are  formed  which  become  visible  to  the  naked  eye,  as  in  Follicular 
and  Granular  Ophthalmia.  In  Phh/ctenular  Conjunctivitis  small 
papules,  or  pseudo-vesicles,  are  found  on  the  bulbar  conjunctiva. 
Severe  cases  of  conjunctivitis  are  often  attended  with  slight  swelling 
of  the  preauricular  gland  ;  but  in  the  condition  known  as  ParinaucVs 
Conjunctivitis  the  glandular  enlargement  is  considerable,  and  reddish 
^vegetations  form  on  the  palpebral  conjunctiva.  Traumatic  Con- 
junctivitis may  be  produced  by  physical  or  chemical  causes,  and 
inflammation  of  the  lacrimal  sac  frequently  extends  to  the  conjunc- 
tiva. In  rare  cases  a  Metastatic  Conjunctivitis  due  to  endogenous 
infection  has  been  observed.  Finally  Eczema,  Impetigo,  and  some 
of  the  exanthemata  (Measles,  Scarlatina,  Small-Pox)  are  frequently 
accompanied  by  conjunctivitis. 

The  Bacteriology  of  Conjunctivitis. — The  micro-organisms  which 
are  commonly  met  with  as  the  active  causes  of  conjunctivitis  are 
not  very  numerous.  The  following  is  a  list  of  them,  with  the  clinical 
type  of  disease  to  which  each  most  frequently  gives  rise  : — 

Bacilli. 

The  Koch-Weeks  B. — (Acute  Contagious  Conjunctivitis).  The 
Diplobacillus  of  Morax — (Subacute  Angular  C).  The  Diphtheria 
B.— (Membranous  C). 

Cocci. 

The  Gonococcus. — (Purulent  C).  The  Pneumococcus. — (Cat- 
arrhal C).     Streptococcus.     Staphylococcus  albus  et  aureus. 

The  last  two  most  frequently  occur  as  part  of  a  mixed  infection, 
along  w4th  the  gonococcus  and  the  diphtheria  bacillus.  They  are, 
however,  also  found,  alone  or  together,  in  the  conjunctivitis  (often 
membranous)  which  accompanies  impetigo  of  the  face,  or  which 
follows  scarlatina,  but  they  have  never  been  known  to  cause  an 
epidemic. 

The  Xerosis  Bacillus  (see  Xerosis),  which  is  non-pathogenic,  is 
very   frequently   present   in  the    normal    conjunctiva    and   in    the 


rnAP.  III.]  THE    CONJUNCTIVA.  40 


Meibomian  secretion ;  but  it  should  also  be  remembered  that  some 
of  the  pathogenic  forms,  such  as  the  staphylococcus,  pneumococcus, 
and,  it  is  stated  by  some,  the  streptococcus,  are  also  found  (especially 
the  first  named)  in  conjunctival  sacs  devoid  of  all  signs  of  irritation. 
In  fact  the  normal  conjunctiva  is  rarely  free  from  micro-organisms, 
and  the  results  obtained  by  cultures  may  vary  from  day  to  day. 
According  to  Mayou  there  are  fewer  micro-organisms  in  the  upper 
fornix  than  in  the  lower. 

The  epithelium  of  the  conjunctiva  offers  a  certain  resistance  to 
the  entrance  of  organisms,  and  hence  many  of  them  will  not  set 
up  an  inflammation  unless  there  be  a  superficial  loss  of  substance. 

All  the  above,  with  the  exception  of  the  gonococcus,  the  Weeks 
bacillus,  and  the  diplobacillus,  stain  by  Gram's  method.^ 

The  number  of  micro-organisms  does  not  always  correspond 
with  the  amount  of  discharge,  and  in  some  instances  none  can  be 
found.  We  have  recently  had  a  case  of  this  kind  in  which,  although 
the  discharge  was  profuse,  both  cover-glass  preparations  and  at- 
tempts to  obtain  cultures  gave  negative  results  on  three  different 
occasions.  The  etiology  of  such  cases  is  unknown ;  they  may 
perhaps  be  due  to  toxins  circulating  in  the  blood  or  to  organisms 
as  yet  undiscovered. 

In  addition  to  those  which  have  been  mentioned,  other  micro- 
organisms have  occasionally  been  found  in  conjunctivitis.  In  the 
case  of  some  of  them  it  is  very  doubtful  if  they  were  the  exciting 
cause  of  the  condition  of  the  conjunctiva  w4th  which  they  were 
associated.  The  most  important  varieties  will  be  briefly  referred 
to  as  we  proceed. 

Catarrhal,  or  Simple  Acute,  or  Muco-purulent  Conjunctivitis.— 
In  mild  cases  the  affection  is  confined  to  the  palpebral  conjunctiva, 
often  even  to  the  conjunctiva  of  the  lower  lid  ;  but  in  the  severer 
cases  it  extends  to  the  bulbar  conjunctiva.  In  the  latter  event 
the  lids  may  be  slightly  hyperaemic  and  swollen.  Both  eyes  are 
usually  affected,  either  simultaneously  or  at  a  short  interval. 
Lymph  follicles  and  enlarged  papillae  are  sometimes  present.     There 

1  For  clinical  work,  in  most  cases,  cover-glass  smears  stained  by  Gram's 
method,  followed  by  a  counter-stain,  such  as  weak  Carbol-Fvichsin,  or 
Loeffler's  ^Methylene  Blue,  will  suffice,  but  in  some  cases  the  identity  of  the 
particular  microbe  can  only  be  established  by  cultures  and  inoculation 
experiments. 
4 


60  DISEASES    OF    THE    EYE.  [chap.  hi. 

is  a  sticky,  thin,  mucous,  or  muco-purulent  secretion  which  is  often 
visible  in  the  form  of  strings  in  the  lower  fornix.  It  dries  on  the 
eyelids  at  night  so  as  to  fasten  them  together  when  the  patient 
awakes  in  the  morning,  and  sometimes  produces  ulceration  of  the 
intermarginal  portion  of  the  eyelids  (intermarginal  blepharitis). 
In  some  of  the  very  mildest  cases  this  stickiness,  or  gumming,  on 
awaking  in  the  morning  is  a  valuable  diagnostic  sign,  for  in  such 
cases  it  is  difficult  or  impossible  to  recognise  by  inspection  the  very 
slight  variation  from  the  healthy  appearance  of  the  conjunctiva. 

In  the  severer  cases  the  papillae  are  markedly  swollen,  and  may 
even  conceal  the  Meibomian  glands  from  view.  Also,  one  often 
sees  small  ecchymoses  in  the  bulbar  conjunctiva,  especially  in  certain 
epidemics  ;    but  these  have  no  serious  import. 

Minute  grey  infiltrations  which  may  break  down  and  form  small 
ulcers  sometimes  appear  at  the  margin  of  the  cornea,  more  especi- 
ally in  old  people.  When  there  are  many  of  them  they  may  become 
confluent  and  form  a  small  grey  crescent,  which  ulcerates,  and  thus 
a  crescentic  marginal  ulcer  is  formed,  and  very  occasionally  such 
an  ulcer  is  followed  by  iritis. 

The  catarrh  may  become  chronic  (p.  56).  The  chronic  form  of 
the  disease  is  much  less  contagious  than  the  acute,  which  frequently 
affects  a  whole  family  or  may  result  in  an  epidemic. 

The  Symptoms  are  those  of  a  severe  case  of  hyperaemia  (sensa- 
tions of  sand  in  the  eye ;  hot,  burning  sensations ;  weight  of  the 
eyelid),  with  the  addition  of  the  annoyance  consequent  on  the 
secretion,  which,  by  coming  across  the  cornea,  may  cause  momentary 
clouding  of  sight.  Photophobia  is  not  generally  severe  unless  there 
be  some  corneal  complication.  The  symptoms  are  worse  at  night, 
or  by  artificial  light,  and  are  much  less  troublesome  when  the  eyes 
are  exposed  to  the  open  air. 

Causes. — Direct  infection  with  secretion,  or  increase  of  the  micro- 
organisms already  present  in  the  conjunctival  sac,  favoured  by 
conditions  which  lower  the  resistance  of  the  tissues,  either  locally 
by  causing  hyperaemia,  or  generally  through  the  system  (impure 
air,  exposure  to  cold,  etc.).  Perhaps  also  the  microbes  are  more 
widespread  or  more  virulent  at  certain  times,  as  in  the  spring  or 
autumn.  Some  of  the  above-mentioned  causes  act,  no  doubt  in 
combination,  in  the  conjunctivitis  which  accompanies  impetigo, 
scarlatina,  measles,  and  smallpox. 


Diplohacillus  {Momx  and  Axen-  Koch-Weeks  bacillus.     Secretion 

jeld).      From   a    case    of    subacute          from  acute  conjunctivitis.     A  few 
angular  conjunctivitis.  deeply  stained  Xerosis  h.  are  also 

present. 


Pneumococciis.     From  a  case  of  Gonococcus.     From  a   case   of 

catarrhal  conjunctivitis.  ophthalmia  neonatorum. 


Xerosis  bacillus.     Culture  from  Xerosis  bacillus.   Culture,  diph- 

normal    conjunctiva,   showing    iew         theroid  form, 
clubs. 

From  preparations  and  drawings  by  L.  W. 


CHAP.  III.]  THE  CONJUNCTIVA.  53 

The  Koch-Weeks  hacillus  produces  an  acute  contagious  con- 
junctivitis, which  chiefly  attacks  young  people,  and  occurs  most 
frequently  in  an  epidemic  form. 

It  is  more  severe  in  adults  than  in  children  ;  and  is  often  attended 
by  an  erythematous  condition  of  the  upper  lids,  or  even  by  slight 
oedema.  Ecchymoses  occur  on  the  bulbar  conjunctiva.  The  pre- 
auricular glands  are  sometimes  enlarged.  The  Koch-Weeks 
bacillus  may  be  easily  overlooked,  as  it  is  a  very  fine  bacillus 
and  stains  feebly.  This  form  of  conjunctivitis  is  not  common  in 
Ireland. 

The  Pneumococcus  is  responsible  for  a  mild  form  of  catarrhal 
ophthalmia,  occurring  in  children  or  adults,  sometimes  in  small 
epidemics.  A  characteristic  sign  of  this  variety  of  conjunctivitis  is 
(according  to  Morax)  an  oedema  or  rose-coloured  hyper^emia  con- 
fined to  the  margin  of  the  upper  lid.  It  also  gives  rise  to  minute 
ecchymosis  of  the  bulbar  conjunctiva.  The  secretion  is  at  times 
fibrinous.  This  variety  does  not  appear  to  be  as  common  in  the 
United  Kingdom  as  elsewhere.  It  is  of  short  duration  (ten  days 
or  so),  and  can  be  readily  cured. 

The  conjunctivitis  associated  with  impetigo  sometimes  assumes 
a  mild  catarrhal  form.  Both  Strepto-  and  Staphylococci  are  found 
to  be  present.  The  former  can  no  doubt  set  up  conjunctivitis,  but 
attempts  to  produce  conjunctivitis  in  man  with  virulent  cultures 
of  staphylococcus  aureus  have  proved  ineffectual. 

In  rare  cases  catarrhal  conjunctivitis  has  been  caused  by  the 
Diplococcus  Intracellularis  Meningitidis,  not  necessarily  accompanied 
by  meningitis. 

In  influenza  epidemics   conjunctivitis   sometimes   occurs   along 
with  the  other  symptoms,  or  it  may  precede  them.     It  is  due  to  the 
Influenza  Bacillus,  which  is  shorter  and  stouter  than  the  Weeks  B. 
but  is  difficult  to  distinguish  from  the  latter.     It  is  much  rarer  in 
adults  than  in  children. 

Cases  of  conjunctivitis  have  also  been  observed,  which  were 
undoubtedly  caused  by  the  hay  bacillus  {B.  Suhtilis.)  In  all  of  them 
particles  of  earth  had  found  their  way  into  the  eye. 

The  Prognosis  of  catarrhal  conjunctivitis  is  good,  if  there  be  no 
reason  to  suspect  that  the  mild  form  is  but  the  commencement  of 
a  more  severe  inflammation.     The  infiltrations,  and  even  the  ulcers 
which  sometimes  form  at  the  margin  of  the  cornea  are  not  often 


54  DISEASES    OF    THE    EYE.  [chap.  hi. 

of   serious   import,  and  usually  heal,  according  as  the  treatment 
restores  the  conjunctiva  to  health. 

Treatment. — It  will  be  advisable  here  to  make  a  few  observations 
on  the  treatment  of  conjunctivitis  in  general.  Patients  should 
always,  in  the  first  place,  be  warned  of  the  danger  of  infecting 
other  persons.  And  in  order  also  to  avoid  re-infecting  themselves, 
droppers  should  be  sterilised,  or  at  least  should  not  be  brought  into 
contact  with  the  eye  when  being  used.  For  bathing  the  eye  sponges 
should  be  avoided,  and  small  pieces  of  lint  employed,  which  must  be 
burnt  immediately  after  use.  Bandages  should  not  be  worn,  nor 
should  the  patient  be  confined  to  the  house,  unless  in  severe  or 
complicated  cases. 

In  catarrhal  conjunctivitis  cold  or  iced  compresses,  with  the  use 
of  a  1  in  5000  solution  of  sublimate  as  a  lotion,  should  be  used 
frequently  at  the  onset,  and  in  mild  cases  will  alone  bring  about  a 
cure.  But  the  habit,  which  some  patients  so  readily  acquire,  of 
bathing  the  eyes  frequently  with  cold  water  should  not  be  permitted, 
for  it  is  deleterious  to  the  conjunctival  affection.  When  in  a  day  or 
two  the  irritation  and  swelling  have  somewhat  subsided — or  from 
the  very  commencement,  if  there  be  discharge — a  solution  of  nitrate 
of  silver,  of  from  5  to  10  grains  to  §j,  should  be  applied  by  the 
surgeon  to  the  palpebral  conjunctiva  with  cotton  wool  twisted  on 
the  end  of  a  small  piece  of  stick,  such  as  is  used  for  matches,  the  lid 
being  well  everted.  The  excess  may  be  neutralised  with  solution 
of  common  salt.  The  neutralisation  with  salt  water  checks  pro- 
longed action  of  the  nitrate  of  silver,  and  obviates  conjunctival 
staining  (called  Argyrosis,  from  apyvpos,  silver)  when  the  treatment 
is  a  lengthened  one.  The  application  is  to  be  repeated  after  twenty- 
four  hours,  by  which  time  the  slight  loss  of  epithelium,  the  result 
of  the  superficial  slough,  will  have  been  repaired.  Immediately 
after  such  an  application  cold  sponging  or  iced  compresses  are  useful, 
and  grateful  to  the  patient.  Gentle  removal  of  the  loose  coagula 
also  gives  much  relief. 

Of  the  organic  silver  salts  the  best  are  protargol,  in  5  to  20  per 
cent  sol.,  sophol  5  per  cent.,  and  argyrol  25  per  cent.  They  do 
not  coagulate  albumen,  and  are  therefore  supposed  to  have  greater 
penetrating  power,  and  are  practically  painless.  Personally  we 
still  rely  on  the  nitrate  in  preference  to  them. 

Even  weak  solutions  of  nitrate  of  silver  as  eye-drops  to  be  used 


CHAP.  III.]  THE    CONJUNCTIVA.  55 


at  home  by  the  patient,  should  be  avoided,  for  staining  of  the  con- 
junctiva is  very  apt  to  be  caused  in  this  way.  Protargol  and  argyrol 
also  cause  staining. 

Subconjunctival  injections  of  Potassium  Iodide,  30  per  cent,  to 
saturated  sol.,  help  to  remove  argyrosis.  Three  or  four  minims  only 
are  injected  at  a  time  on  account  of  the  rather  severe  reaction. 

Should  the  surgeon  be  unable  to  see  the  patient  daily,  astringent 
and  antiseptic  eye-drops  are  very  beneficial,  and  indeed  often  effect 
a  cure.  Sulphate  of  zinc  (gr.  ij  to  the  5J),  with  or  without  Tinct. 
Opii,  3jj  alum  (gr.  iv  to  5J),  tannic  acid  (gr.  v  to  viij  to  §j)  are  those 
which  are  most  commonly  used.  They  may  be  combined  with 
boracic  acid  in  saturated  solution,  corrosive  sublimate  (1 — 5000), 
or  oxycyanate  of  mercury  (1 — 2000).  Acetate  of  lead  (gr.  1  or  ij  to 
5J)  can  also  be  prescribed,  provided  the  cornea  be  intact;  other- 
wise deposits  of  lead  are  liable  to  form  in  it. 

A  weak  boracic  acid  ointment  should  be  applied  along  the 
margins  of  the  lids  at  bedtime.  It  prevents  the  adhesion  of  the 
lids  in  the  morning,  which  is  not  only  unpleasant  to  the  patient, 
but  also  prevents  free  drainage  of  the  secretion  during  sleep. 

Diplobacillary  or  Angular  Conjunctivitis.— This  form  of  in- 
flammation requires  a  description  apart,  not  only  because  it  pre- 
sents a  definite  clinical  picture,  but  also  because  it  readily  yields, 
to  a  particular  line  of  treatment.  It  presents  the  appearance  of  a 
subacute  or  chronic  conjunctivitis,  the  congestion  being  limited  to 
the  palpebral  conjunctiva,  more  especially  of  the  lower  lid,  and  to 
the  caruncle.  The  secretion  is  very  scanty,  and  makes  its  appear- 
ance most  commonly  round  the  inner  canthus,  as  a  slight  greyish- 
white  collection,  but  still  the  lids  are  often  stuck  together  in  the 
mornings.  The  most  characteristic  sign,  and  one  which  has  given 
rise  to  the  name  "  Angular,"  is  a  peculiar  moist  hyperaemia,  with 
superficial  excoriation,  of  the  skin  at  the  margin  of  the  lids,  which 
usually  surrounds  the  canthi,  especially  the  inner  canthus,  although 
the  whole  margin  of  the  lids  may  be  affected  by  it.  In  very  mild 
cases  this  condition  of  the  skin  may  be  absent.  The  subjective 
symptoms  consist  in  sensations  of  heat,  pricking,  and  itching,  and 
are  always  much  worse  in  the  evening.  Corneal  affections  are 
not  common,  but  occasionally  small  superficial  marginal  ulcers 
occur  ;  and,  less  frequently  still,  severe  central  ulcers  with  hypopyon 
(see  chap.  v.). 


56  DISEASES    OF    THE    EYE.  [chap.  hi. 


The  disease  is  chiefly  met  with  in  adults,  but  it  also  occurs  in 
children,  in  whom  it  may  even  cause  blepharitis.  We  have  often 
seen  it  too  as  a  complication  of  trachoma  in  the  later  stages. 

Cause. — The  exciting  cause  is  the  Diplobacillus  of  Morax  and 
Axenfeld,  the  largest  of  the  micro-organisms  found  in  the  con- 
junctival sac  (see  p.  51).  It  grows  only  on  sohd  media  containing 
serum,  in  which  it  produces  very  characteristic  clear  depressions. 
Inoculation  easily  succeeds  in  reproducing  the  disease,  but  only  in 
human  beings.  The  diplobacilli  have  also  been  found  in  the  nose, 
but  it  has  not  been  definitely  ascertained  whether  or  not  they 
reach  the  latter  through  the  nasal  duct. 

Treatment. — This  affection  shows  no  tendency  to  spontaneous 
cure,  and,  if  neglected,  it  may  last  for  many  months  ;  but  fortunately 
we  have  in  sulphate  of  zinc  an  unfailing  remedy.  Solutions  of  from 
4  to  10  grains  to  the  ounce  will  effect  a  cure  in  ten  days  or  so,  and 
are  much  more  efficacious  than  very  weak  solutions,  and  are  not 
very  painful.  Cocaine  may  be  added  for  patients  of  nervous  tem- 
perament. In  order  to  prevent  a  relapse,  the  treatment  should 
always  be  continued  for  about  a  week  after  the  subjective  symptoms 
have  disappeared.  If  the  lids  be  tender,  an  ointment  of  oxide  of 
zinc  (10  per  cent.)  and  icthyol  (2  to  5  per  cent.)  is  very  useful.  The 
sulphate  of  zinc  does  not  kill,  but  merely  checks  the  growth  of  the 
bacilli,  hence  the  necessity  for  prolonging  the  treatment  after  an 
apparent  cure. 

In  rare  cases  of  idiosyncrasy  to  zinc  sulphate,  resorcin  in  2  or 
3  per  cent,  aqueous  solution  gives  good  results. 

Chronic  Simple  or  Chronic  Catarrhal  Conjunctivitis.— This  form 
of  conjunctivitis  occurs  in  adults  and  old  people,  and  is  extremely 
obstinate,  often  lasting  for  years,  and  sometimes,  with  or  without 
intermissions,  even  for  a  lifetime.  The  objective  signs  vary  in 
degree  from  those  of  simple  hypersemia  without  apparent  secretion 
to  a  moderate  catarrh  with  muco-purulent  discharge.  But  they 
are  never  so  pronounced  as  in  the  acute  form  of  the  disease,  and 
the  bulbar  conjunctiva  is  seldom  much  injected. 

The  subjective  symptoms  resemble  those  which  have  been  men- 
tioned in  the  descriptions  of  hypersemia  and  acute  catarrh.  They 
are  always  worse  in  the  evening,  and  patients  often  complain  that 
when  they  attempt  to  read,  the  upper  lids  feel  heavy  and  inclined 
to  close,  so  that  they  feel  sleepy.     A  sensation  of  dryness  of  the  eye- 


CHAP.   III.]  THE    CONJUNCTIVA.  57 


ball  is  also  experienced,  when  the  secretion  is  scanty  or  absent.  In 
many  cases,  however,  the  sensations  complained  of  are  much  in 
excess  of  the  objective  appearances. 

In  the  later  stages,  the  conjunctiva,  in  muco-purulent  cases, 
becomes  rough  or  velvety,  from  hypertrophy  of  the  papillae,  and 
ectropion  of  the  lower  lid,  epiphora,  and  blepharitis  may  result. 
The  skin  of  the  lower  lid,  from  the  constant  irritation  caused  by 
the  discharge,  becomes  eczematous  and  stif?,  the  inner  end  of  the 
lid  then  becomes  everted,  so  that  the  punctum  lacrimale  no  longer 
lies  in  normal  contact  with  the  eyeball,  and  this,  together  with 
narrowing  of  the  punctum  and  canaliculus  by  the  hypertrophied 
conjunctiva,  leads  to  epiphora,  which  again  intensifies  the  irritation 
of  the  skin,  and  still  further  increases  the  ectropion.  Marginal  ulcers 
of  the  cornea,  too,  are  liable  to  occur  in  old  people  with  chronic 
conjunctival  catarrh. 

The  Causes  of  this  affection  are  very  numerous.  It  seldom 
originates  in  an  acute  catarrh,  but  more  commonly  begins  gradually, 
and  owes  its  origin  to  local  irritation  of  the  conjunctiva  or  to  con- 
stitutional causes.  Amongst  the  former  are  included  dust,  chemicals, 
smoke,  bad  ventilation,  exposure  to  heat  or  steam,  in- turned  eye- 
lashes, infection  from  the  lacrimal  sac,  errors  of  refraction,  prolonged 
reading  by  artificial  light,  sleeplessness,  and  constant  exposure  to 
wind  or  rain.  Less  well-known  causes  are  :  inefficient  closure  of 
the  eyelids  at  night,  so  that  a  portion  of  the  eyeball  remains  exposed 
to  the  atmosphere  ;  purulent  infection  of  the  ducts  of  the  Meibomian 
glands,  or  soHd  infarcts  in  the  Meibomian  glands  or  in  small  con- 
junctival cysts.     In  many  cases  no  definite  cause  can  be  assigned. 

Treatment  is  often  unsatisfactory,  partly  owing  in  many  cases  to 
the  impossibility  of  removing  the  cause  when  this  is  due  to  the 
nature  of  the  patient's  occupation.  Indications  for  treatment  are 
provided  by  a  consideration  of  the  above-mentioned  causes.  Atten- 
tion should  also  be  paid  to  the  general  health  ;  relief  of  constipa- 
tion ;  avoidance  of  alcoholic  stimulants  ;  correction  of  errors  of 
refraction  and  presbyopia  ;  treatment  of  the  lacrimal  apparatus 
(chap,  xix.)  and  of  ectropion  (chap,  xviii.).  In  case  of  defec- 
tive closure  of  the  lids,  a  bandage  at  night  may  be  applied.  Sup- 
puration in  the  Meibomian  ducts  can  be  effectually  relieved  by 
expression  of  their  contents,  daily  if  necessary.  Any  solid  white 
infarcts^  if  they  project  above  the  surface,  should  be  picked  out  of 


58  DISEASES    OF    THE    EYE.  [chap.  hi. 

the  palpebral  conjunctiva  with  the  point  of  a  needle  or  knife.  With 
regard  to  local  applications,  astringents  are  the  most  useful,  but 
they  should  not  be  too  irritating.  Nitrate  of  silver  may  be  necessary 
if  there  be  discharge  or  hypertrophy  of  the  conjunctiva.  Protargol, 
argyrol,  or  other  organic  silver  salts  are  less  painful,  but  the  possibility 
of  causing  argyrosis  should  not  be  forgotten.  Other  useful  astrin- 
gents are  alum  in  solid  stick,  or  in  J  to  1  per  cent,  solution  ;  copper 
sulphate ;  lead  subacetate  ;  tannic  acid  in  solutions  containing 
1  or  2  grains  to  5J.  Boracic  acid  too  may  be  used  in  saturated 
solution,  but  it  is  the  mildest  and  least  active  of  all.  Adrenaline 
gives  only  temporary  relief.  Frequent  use  of  cocaine  is  not  to  be 
recommended,  as  it  renders  the  cornea  vulnerable  to  micro-organisms 
by  deranging  its  epithelium.  Very  mild  cases  of  diplobacillary 
conjunctivitis  may  not  be  accompanied  by  the  characteristic  ex- 
coriation of  the  skin,  and  may  then  resemble  a  simple  chronic 
conjunctivitis  ;  but  here  a  bacteriological  examination  would  at 
once  establish  the  diagnosis  and  suggest  the  appropriate  treatment. 

Acute  Blennorrhoea  of  the  Conjunctiva,  or  Purulent  Ophth- 
almia.— This  very  dangerous  affection,  which  statistics  show  to  be 
one  of  the  commonest  causes  of  blindness,  is  usually  seen  either  as 
gonorrhoeal  ophthalmia  or  as  blennorrhoea  neonatorum. 

Etiology. — In  gonorrhoeal  ophthalmia  the  etiological  moment 
is  the  introduction  of  some  of  the  specific  discharge  from  the  ure- 
thra or  vagina  into  the  conjunctival  sac  ;  while  in  blennorrhoea 
neonatorum  the  infection  is  believed  to  take  place,  either  during 
or  just  after  the  passage  of  the  head  through  the  vagina,  by  ab- 
normal secretion  from  the  latter  finding  its  way  into  the  infant's 
eyes.  A  few  instances  have  been  observed  of  infants  born  with 
the  disease.  Prolonged  labour,  due  to  early  rupture  of  the  mem- 
branes, or  faulty  head  presentations,  and  also  repeated  examina- 
tions, would  assist  infection  before  delivery.  Inoculation  may  also 
occur  a  few  days  after  birth  by  pus  conveyed  by  the  fingers  of  the 
mother  or  nurse,  or  by  towels,  etc.,  used  for  washing  the  child's  face. 

The  more  severe  cases  of  blennorrhoea  neonatorum  are  caused 
by  a  vaginal  discharge,  which  is  almost  always  gonorrhoeal,  and 
Neisser's  gonococcus,  which  is  the  exciting  agent,  can  be  found  in 
the  discharge  from  the  vagina  and  in  the  secretion  from  the  eye. 
It  may  be  found  in  the  epithelial  cells,  or  in  the  pus  cells,  or  free. 
Mild  catarrhal  conjunctivitis  also  occurs  in  newborn  infants,  and  in 


CHAP.  III.]  THE    CONJUNCTIVA.  59 


these  cases  the  ordinary  microbes  associated  with  that  condition  are 
present,  and  occasionally  the  bacterium  coli ;  but  in  rare  cases  even 
the  gonococcus  may  produce  a  mild  reaction,  probably  owing  to 
attenuation  of  the  virus  by  dilution  or  drying.  It  should  also  be 
noted  that  a  typically  purulent  ophthalmia  has,  in  exceptional 
cases,  been  observed  in  infants  (Morax)  without  the  presence  of 
any  micro-organisms,  but  then  it  usually  takes  a  benign  course. 

If  the  infection  take  place  during  or  immediately  after  birth, 
the  disease  appears  most  commonly  on  the  third  day,  but  it  may 
appear  at  any  time  from  the  second  to  the  sixth  day,  according  to 
the  virulence  of  the  secretion.  If  the  inflammation  come  on  later 
than  the  sixth  day,  it  may  be  concluded  that  the  infection  was 
produced  secondarily  by  the  vaginal  discharge  being  introduced 
into  the  eye  by  the  fingers  of  the  mother  or  nurse,  etc. 

While  purulent  ophthalmia  in  adults  is  usually  gonorrhoeal  and 
due  to  the  gonococcus,  it  may  exceptionally  be  the  result  of  in- 
fection by  the  Koch-Weeks  bacillus  ;  the  cases  due  to  this  bacillus, 
however,  are  not  so  serious  as  those  caused  by  the  gonococcus. 

In  newborn  infants  both  eyes  are  commonly  affected.  The 
reverse  is  the  case  in  adults,  in  whom  also  the  disease  is  more  severe. 

Symptoms  and  Progress. — In  mild  cases  the  bulbar  conjunctiva 
may  be  but  little,  or  not  at  all,  affected,  the  palpebral  conjunctiva 
alone  becoming  velvety  and  discharging  a  small  amount  of  pus, 
while  there  may  be  no  swelling  or  oedema  of  the  eyelids. 

In  severe  cases  of  blennorrhoea  of  the  conjunctiva  there  is, 
soon  after  the  onset,  serous  infiltration  of  the  palpebral  mucous 
membrane — which  consequently  becomes  tense  and  shiny — marked 
chemosis  of  the  bulbar  conjunctiva,  serous  discharge,  dusky  red- 
ness, and  swelling  of  the  eyelids — which  makes  it  difficult  to  evert 
them — pain  in  the  eyelids,  often  of  a  shooting  kind,  burning  sensa- 
tions in  the  eye,  and  photophobia.  This  first  stage,  or  period  of 
infiltration,  lasts  from  forty-eight  hours  to  four  or  five  days.  The 
preauricular  lymphatic  glands  may  be  swollen  and  tender,  and  a 
rise  of  temperature  may  occur. 

Then  begins  the  second  or  furulent  stage,  in  which,  owing  to 
swelling  of  the  papillae,  the  palpebral  conjunctiva  becomes  less 
shiny  and  more  velvety  ;  while  the  discharge  alters  from  serous 
to  the  characteristic  purulent  form,  the  chemosis,  however,  remaining 
unaltered,  or  becoming  more  firm  and  fleshy.     The  swelling  of  the 


60  DISEASES    OF    THE    EYE.  [chap.  hi. 


lids  continues,  the  upper  lid  often  becoming  pendulous  and  hang- 
ing down  over  the  under  lid  ;  while,  at  the  same  time,  it  becomes 
less  tense  and  more  easily  everted.  Gradually  the  chemosis  and 
swelling  of  the  conjunctiva  and  eyelids  subside,  and  the  discharge 
lessens,  the  mucous  membrane  finally  being  left  in  a  normal  state, 
unless  in  a  small  percentage  of  cases  in  which  chronic  blennorrhoea 
remains.  A  moderately  severe  attack  of  conjunctival  blennorrhoea 
lasts  from  four  to  six  weeks.  A  delicate  scarring  of  the  conjunctiva 
in  the  fornices  may  be  sometimes  left  after  the  attack. 

Complications  with  corneal  affections  form  the  greatest  source  of 
danger  in  this  affection.  They  are  found  chiefly  in  four  different 
forms.  (1)  Small  epithelial  losses  of  substance  which  are  apt  to  go 
on  to  form  deep  perforating  purulent  ulcers.  (2)  The  whole  cornea 
becomes  opaque  (diffusely  infiltrated),  and  greyish  purulent  in- 
filtrations may  form  towards  its  centre.  (3)  An  infiltration  may  form 
at  the  margin  of  the  cornea,  and  give  rise  to  a  marginal  ring  ulcer, 
and,  later  on,  to  sloughing  of  the  whole  cornea.  (4)  A  clean-cut  ulcer 
may  also  form  at  the  margin  of  the  cornea.  These  ulcers  are  par- 
ticularly apt  to  occur  where  there  is  much  chemosis,  which  overlaps 
the  margin  of  the  cornea  ;  and,  being  hidden  in  this  way,  they  are 
easily  overlooked.  The  chemosis  should  be  pushed  aside  with  a 
probe,  and  these  peculiar  ulcers  looked  for.  They  are  very  liable 
to  perforate. 

All  the  foregoing  forms  of  corneal  complication  occur  both  in 
adults  and  infants,  and  the  earlier  they  occur  the  more  likely  are  they 
to  result  in  perforation  and  permanent  opacities. 

It  is  believed  by  some  that  corneal  complications  are  due  to 
secondary  infection  with  other  micro-organisms. 

The  severer  the  case,  especially  the  more  the  bulbar  conjunctiva 
is  involved  in  the  process,  the  more  likely  is  it  that  corneal  com- 
plications will  arise.  Severe  chemosis  is  less  common  in  the  blennor- 
rhoea of  the  newborn  than  in  gonorrhoeal  ophthalmia,  and  this  may 
be  the  reason  for  the  fact  that  the  latter  is  much  the  more 
dangerous  affection  of  the  two. 

The  Prophylaxis  of  purulent  ophthalmia  is  a  matter  of  the  first 
importance.  It  should  form  part  of  the  routine  of  lying-in  practice. 
Careful  disinfection  of  the  vagina  before  and  during  birth,  and 
the  most  minute  care  in  cleansing  the  face  and  eyes  of  the  infant 
immediately  after   birth   with  a  non-irritating  disinfectant   {e.g.   a 


CHAP.  ITT.]  THE    CONJUNCTIVA.  01 

solution  of  corrosive  sublimate  1  iu  5000),  are  to  be  recommended. 
Crede's  method  is  as  follows  : — When  the  child  is  in  the  bath,  the 
eyes  are  carefully  washed  with  water  from  a  separate  vessel,  the 
lids  being  scrupulously  freed,  by  means  of  absorbent  wool,  of  all 
blood,  slime,  or  smeary  substance  ;  and  then,  before  the  child  is 
dressed,  a  few  drops  of  a  2  per  cent,  solution  of  nitrate  of  silver  are 
instilled  into  the  eye.^  The  conjunctival  irritation  which  some- 
times follows  is  unimportant  as  compared  with  the  immense 
advantages  which  result  from  this  procedure.  By  its  aid  Crede 
reduced  the  percentage  of  his  cases  of  ophthalmia  neonatorum  from 
8  or  9  per  cent,  to  0*5  per  cent.  Very  good  results  have  also  been 
obtained  with  5  per  cent,  sophol. 

In  all  cases  of  gonorrhoea  it  is  the  duty  of  the  surgeon  to  explain 
to  his  patients  the  danger  of  carrying  any  of  the  urethral  discharge 
to  their  eyes  ;  and  to  charge  them  to  exercise  punctilious  cleanli- 
ness as  regards  their  hands  and  finger-nails,  and  care  in  the  use 
of  towels,  handkerchiefs,  etc. 

In  respect  of  Local  Treatment  when  the  disease  has  become 
established  : — In  the  very  commencement  of  the  affection  the  only 
local  applications  admissible  are  antiseptic  lotions  (Permanganate 
of  Potash  Solution,  1  in  10,000  ;  Sublimate,  1  in  5000)  and  iced 
compresses,  or  Leiter's  tubes.  With  the  former  the  conjunctival 
sac  should  be  freely  washed  out  or  irrigated.  Syringing  is  dangerous 
both  for  patient  and  for  operator,  for  in  syringing  out  the  conjunc- 
tival sac  the  corneal  epithelium  may  be  injured  and  the  cornea  may 
become  infected  ;  and,  as  regards  the  operator,  he  is  in  danger  of 
discharge  spurting  into  his  eyes.  The  iced  compresses,  or  Leiter's 
tubes,  should  be  kept  to  the  eye  for  an  hour  at  a  time,  with  a  pause 
of  an  hour,  and  so  on,  or  even  continuously.  Cold  inhibits  the 
growth  of  the  gonococcus.  In  this  and  in  the  next  stage  the  chemosis, 
if  severe,  should  be  freely,  and  daily,  incised  with  scissors.  If 
the  swelling  of  the  lids  be  great,  the  external  canthus  should  be 
divided  wdth  a  scalpel  from  without,  leaving  the  conjunctiva  un- 
injured, in  order  to  reduce  the  tension  of  the  eyelids  on  the  globe, 
and,  by  bleeding  from  the  small  vessels,  to  deplete  the  conjunctiva. 
Depletion  alone  can  be  obtained  by  leeching  at  the  external  canthus, 
and  in  many  cases  is  of  great  benefit  at  the  very  commencement. 

^  The  general  opinion  now  is  that  a  1  per  cent,  solution  is  just  as 
efficient  and  less  irritating. 


62  DISEASES    OF    THE    EYE.  [chap.  hi. 

If  in  iidults  the  cliemosis,  palpebral  swelling,  and  rapidity  of  the 
onset  indicate  that  the  inflammation  is  severe,  it  is  well  to  place 
the  patient  quickly  under  the  influence  of  mercury  by  means  of 
inunctions  or  small  doses  of  calomel,  as  by  so  doing  the  cliemosis 
is  often  rapidly  brought  down,  and  one  source  of  danger  to  the  cornea 
is  removed. 

In  the  second  stage  {i.e.  when  the  conjunctiva  has  become  velvety 
and  the  discharge  purulent)  caustic  applications  are  the  most  trust- 
worthy, and  in  this  respect  iodoform  and  other  lauded  means 
cannot  compete  with  them.  The  surgeon  should  apply  a  solution  of 
nitrate  of  silver  of  10  to  20  grains  in  §j  of  water,  to  the  conjunctiva 
of  the  everted  lids  ;  or  the  solid  mitigated  nitrate  of  silver  (one 
part  nitrate  of  silver,  two  parts  nitrate  of  potash)  may  be  used,  the 
first  application  being  lightly  made  in  order  to  test  its  effect,  while 
careful  neutralisation  with  salt  water  and  subsequent  washing  with 
fresh  water  are  most  important.  Iced  compresses  may  be  used 
to  relieve  the  subsequent  pain.  An  interval  of  twenty-four  hours 
should  elapse  before  the  application  is  renewed.  No  remedy  is  of 
greater  value  in  purulent  ophthalmia  than  the  above  mentioned 
mitigated  lapis,  wdien  the  proper  indications  for  its  use  are  present, 
and  when  it  is  applied  with  care  and  intelligence.  Betw^een  the 
caustic  applications,  the  pus  should  be  frequently  washed  away  from 
the  eyelids,  and  from  between  the  eyelids,  with  a  -i  per  cent, 
solution  of  boric  acid,  or,  better  still,  the  conjunctiva  should  be 
douched  with  a  solution  of  permanganate  of  potash  (1  in  5000)  or 
with  a  solution  of  corrosive  sublimate  of  the  same  strength,  and 
boric  acid  ointment  should  be  smeared  along  the  palpebral  margins, 
to  prevent  them  from  adhering,  and  thus  retaining  the  pus. 

No  corneal  complication  contra-indicates  the  active  treatment 
of  the  conjunctiva  by  the  method  just  described.  Iodoform,  finely 
pulverised,  has  been  much  praised  as  a  local  application  in  the 
second  stage  of  acute  blennorrhoea  of  the  conjunctiva.  It  is  to  be 
dusted  freely  on  the  conjunctiva  once  or  twice  a  day.  For  our  part 
we  should  trust  to  it  alone  in  mild  cases  only.  It  can,  however, 
be  employed  with  advantage  in  combination  with  the  above  treat- 
ment. 

AVhen  but  one  eye  is  aflected,  it  is  generally  considered  neces- 
sary to  protect  its  fellow  from  infection  by  means  of  a  hermetic 
dressing.     This  may  be  made  by  applying  to  the  sound  eye  a  piece 


CHAP.  III.]  THE    CONJUNCTIVA.  03 

of  lint  covered  with  boracic  acicT  ointment,  and  over  this  a  pad  of 
borated  cotton-wool.  Across  this,  from  forehead  to  cheek  and 
from  nose  to  temporal  region,  are  laid  strips  of  lint  soaked  in 
collodion  in  layers  over  each  other  ;  or  a  piece  of  tissue  guttapercha 
may  take  the  place  of  the  lint  and  collodion,  its  margins  being 
fastened  to  the  skin  by  collodion.  The  shields  invented  by  Maurel 
and  by  BuUer  are  serviceable  for  this  purpose.  Yet  with  careful 
instructions  given  to  the  patient,  and  average  intelligence  on  his 
part,  protection  of  the  sound  eye  is  not  necessary.  In  private  cases 
we  do  not  close  the  second  eye,  and  have  never  had  ill  effects  in 
consequence.  Any  sign  of  congestion  was  met  by  the  application 
of  a  2  per  cent,  solution  of  nitrate  of  silver,  and  it  always  proved 
sufficient  to  check  the  development  of  the  disease,  as  it  does  in 
Crede's  method  of  prophylaxis. 

Patients  should  be  advised  to  sleep  on  the  side  of  the  affected 
eye,  in  order  to  prevent  the  discharge  from  trickling  on  to  the  other 
side  of  the  face. 

Treatment  of  Corneal  Complications. — The  involvement  of  the 
cornea  does  not  contra- indicate  the  use  of  the  methods  already 
described,  but  rather  demands  their  vigorous  application.  In 
addition,  atropine  will  relieve  pain  and  diminish  the  tendency  to 
iritis.  Eserine  is  sometimes  employed  with  the  object  of  reducing 
the  tension,  and  so  improving  the  nutrition  of  the  cornea  by  facili- 
tating the  lymph  circulation,  and  also  on  account  of  its  antiseptic 
properties.  But,  as  its  action  on  the  normal  tension  is  practically 
nil,  and  its  antiseptic  properties  are  very  slight,  it  is  better  to  reserve 
it  for  cases  of  marginal  ulcer  with  prolapse,  or  danger  of  prolapse, 
of  the  iris,  since  by  the  contraction  of  the  sphincter  the  iris  is  drawn 
away  from  the  periphery.  Greater  care  is  now  required  in  everting 
the  lids,  lest  pressure  on  the  globe  should  cause  rupture  of  the  ulcer  ; 
and  it  must  be  remembered  that  when  a  case  of  acute  blennorrhoea 
first  presents  itself,  the  surgeon,  not  knowing  the  condition  of  the 
cornea,  must  use  the  utmost  caution  in  making  his  examination, 
and  yet  must  never  fail  to  get  a  view  of  the  cornea  for  the  purposes 
both  of  prognosis  and  of  treatment.  At  each  visit  the  cornea  must 
be  examined,  and  it  may  be  found  that,  as  the  conjunctival  process 
subsides,  any  existing  corneal  affection  also  improves.  But  even 
though  the  conjunctiva  be  improving,  the  corneal  process  may 
progress,  until,  finally,  the  ulcer  perforates. 


CA  DISEASES    OF    THE    EYE.  [cHAr.  in. 

Should  a  corneal  ulcer  become  deep,  aud  seem  to  threaten  to 
perforate,  paracentesis  of  the  floor  of  the  ulcer  must  be  resorted  to 
without  delay.  Through  the  small  linear  opening  thus  made  no 
prolapse  of  the  iris,  or  else  a  relatively  small  one,  takes  place. 
The  reduction  of  the  intra-ocular  tension  after  the  paracentesis 
promotes  healing  of  the  ulcer.  It  is  often  desirable  to  evacuate  the 
aqueous  humour,  by  opening  the  little  incision  in  the  floor  of  the 
ulcer  with  a  blunt  probe,  on  each  of  the  two  days  after  the  operation. 

If  an  ulcer  perforate  spontaneously,  the  aqueous  humour  is 
evacuated,  and,  unless  the  ulcer  be  opposite  the  pupil  and  at  the 
same  time  small  in  size,  the  iris  must  come  to  be  applied  to  the 
loss  of  substance.  Should  the  latter  be  very  small,  the  iris  will 
simply  be  stretched  over  it  and  pass  but  little  into  its  lumen,  and 
when  healing  takes  place  will  be  caught  in  the  cicatrix,  which  is  but 
slightly,  or  not  at  all,  raised  over  the  surface  of  the  cornea,  and 
the  resulting  condition  is  called  Anterior  Synechia. 

If  the  perforation  be  larger,  a  true  prolapse  of  a  portion  of  the 
iris  into  the  lumen  of  the  ulcer  takes  place.  This  prolapse  may 
either  act  as  a  plug,  filling  up  the  loss  of  substance  and  keeping 
back  the  contents  of  the  globe,  but  not  protruding  over  the  level 
of  the  cornea,  or  it  may  bulge  out  over  the  corneal  surface  as  a  black 
globular  swelling,  and  may  then  play  the  part  of  a  distensor  of  the 
opening,  causing  fresh  infiltration  of  its  margins.  In  either  case 
cicatrisation  will  eventually  occur  ;  and  if  the  scar  be  fairly  flat, 
it  is  called  an  Adherent  Leucoma,  but  if  it  be  bulged  out,  the  term 
Partial  Staphyloma  of  the  Cornea  is  used. 

If  the  perforation  be  very  large,  involving  the  greater  part 
of  the  cornea,  with  prolapse  of  the  whole  iris  and  closure  of  the 
pupil  by  exudation,  the  result  is  a  Total  Staphyloma  of  the  Cornea. 
The  lens  may  lie  in  this  staphyloma,  or  it  may  retain  its  normal 
position,  but  become  shrunken. 

The  question  of  the  treatment  of  a  recent  prolapse  of  the  iris 
in  cases  of  blennorrhoeic  conjunctivitis  is  an  important  one.  It 
has  been,  and  is  still  largely,  the  practice  to  abscise  small  iris-pro- 
trusions down  to  the  level  of  the  cornea,  or  if  large  to  cut  a  small 
bit  off  their  summits,  with  the  object  of  obtaining  flat  cicatrices. 
But  in  cases  of  blennorrhoea  this  proceeding  opens  a  way  for  purulent 
infection  of  the  deep  parts  of  the  eye,  and  serious  consequences 
may  result.     It  is  better  to  confine   interference  with  the  iris  in 


CHAP.  III."!  THE    CONJUNCTIVA, 


these  eyes  to  incision  of  the  prolapse,  when  it  seems  to  be  acting 
as  a  distensor  of  the  opening,  causing  fresh  infiltration  of  the  cornea  ; 
or  merely  to  instil  eserine,  which  has  a  marked  effect  in  diminishing 
the  size  of  the  protrusion. 

The  margins  of  the  eyelids  may  be  gummed  together  by  sero- 
purulent  secretion,  while  the  eyelids  are  bulged  out  by  the  pent-up 
fluid  behind  them  ;  the  attempt  to  open  the  eye  should  then  be 
very  cautiously  made,  lest  some  of  the  retained  pus  spurt  into  the 
surgeon's  eye.  The  surgeon  should  also  be  most  careful  to  wash 
thoroughly  and  disinfect  his  hands  and  nails  at  the  conclusion  of 
his  visit. 

In  cases  of  blennorrhoea  neonatorum,  when  the  ulcer  has  been 
small,  on  perforation  taking  place,  the  lens,  or  rather  the  anterior 
capsule,  comes  to  be  applied  to  the  posterior  aspect  of  the  cornea. 
The  pupillary  area  is  soon  filled  with  fibrinous  secretion.  The  open* 
ing  in  the  cornea  ultimately  becoming  closed,  the  iris  and  lens  are 
pushed  back  into  their  places  by  the  aqueous  humour  which  has 
again  collected.  Adherent  to  the  anterior  capsule  where  it  Jay 
against  the  cornea  is  a  deposit -of  fibrine,  which  gradually  becomes 
absorbed  by  the  aqueous  humour.  In  the  meantimxe  changes  have 
been  produced  by  this  exudation  on  the  corresponding  intracapsular 
cells,  which  result  in  a  small,  permanent,  central  opacity  at  that 
place,  where  there  is  also  a  sHght  elevation  of  pyramidal  shape  over 
the  level  of  the  capsular  surface.  This  condition  is  called  central 
capsular  cataract,  or  pyramidal  cataract,  and  rarely  results  from 
cornea]  perforation  in  adults. 

In  cases  of  blennorrhoea  neonatorum  an  inflammatory  swelling 
of  the  joints,  so-called  gonorrhoeal  arthritis,  is  very  occasionally 
seen.  The  gonococcus  has  been  found  in  the  fluid  removed  from 
the  joints  in  some  cases,  while  in  others  only  the  usual  pyogenic 
cocci  were  present.  Even  more  rarely  do  peri-  and  endo-carditis, 
pleuritis,  and  meningitis  occur. 

Metastatic  Gonorrhoeal  Ophthalmia  is  sometimes  met  with  in  adolescents 
or  adults,  as  an  accompaniment  of  gonorrhceal  artliritis.  It  is  apt  to  occur 
with  cessation  of  the  urethral  discharge.  Both  eyes  are  nearly  always 
affected.  The  disease  presents  the  appearance  of  a  moderate  catarrhal 
ophthalmia  chiefly  affecting  the  bulbar  conjunctiva,  with  scanty  secretion, 
but  it  is  occasionally  complicated  with  keratitis,  iritis,  or  scleritis.  It 
shows  a  great  tendency  to  recur  with  a  relapse  of  the  "  rheumatism."  On 
the  other  hand,   the  conjunctival  affection  may  be   the   only  sign  of   a 

5 


OG  DISEASES    OF    THE    EYE.  [chap.  hi. 


systemic  affection.  Gonococci  have  sometimes  been  found  in  the  secre- 
tion from  the  conjunctiva.  Tliree  views  are  held  with  regard  to  causa- 
tion :  (a)  that  the  gonococci  are  carried  to  the  eye  through  the  circulation ; 
(6)  that  it  is  due  to  a  gonotoxin  ;  or  (c)  that  the  gonococci  prepare  the 
soil  for  a  mixed  infection.     It  is  easily  cured  by  local  treatment. 

Quite  recently  good  results  have  been  obtained,  in  all  forms  of  gonor- 
rhoeal  infection,  with  an  atoxic  gonococcal  vaccine  prepared  in  the  Pasteur 
Institute  of  Tunis  according  to  a  formula  of  Nicolle  and  Blaizot. 

*  Membranous  Conjunctivitis. — This  disease  is  characterised 
by  the  existence  of  a  fibrinous  exudation,  either  on  the  surface  or 
in  the  substance  of  the  conjunctiva,  in  addition  to  the  other  symp- 
toms of  inflammation.  It  was  formerly  believed,  on  purely  clinical 
grounds,  that  the  mild  form  of  the  disease,  known  as  croupous 
conjunctivitis,  was  totally  different  in  nature  from  the  severe  or 
diphtheritic  form,  and  later  on  this  view  seemed  to  be  borne  out 
by  the  discovery  of  the  Klebs-Loeffler  bacillus  in  the  diphtheritic 
cases  ;  but  further  experience  of  the  bacteriology  of  membranous 
conjunctivitis  has  altered  this  view.  Not  only  is  the  diphtheria 
bacillus  found  in  mild  croupous  cases,  but  any  of  the  micro-organisms 
which  commonly  cause  conjunctivitis,  may  give  rise  to  fibrinous 
exudations  and  the  formation  of  membranes.  The  same  condition 
in  varying  degrees  of  severity  can  be  produced  by  chemical  irritants, 
such  as  lime,  ammonia,  etc.,  and  also  by  jequirity.  Lastly,  the 
diphtheria  bacillus  may,  in  rare  cases,  lead  to  a  simple  catarrhal 
inflammation  without  the  production  of  a  false  membrane.  The 
presence  of  a  membrane  therefore  is  only  a  symptom,  and  is  not 
necessarily  pathognomonic,  although  it  is  very  suggestive  of  the 
Klebs-Loeffler  bacillus  as  the  cause. 

In  severe  cases  strepto-  and  staphylo-cocci  are  generally  associ- 
ated with  the  diphtheria  bacillus,  and  indeed  the  streptococcus, 
staphylococcus,  and  pneumococcus  acting  alone  can  occasionally 
cause  severe  membranous  inflammation  of  the  conjunctiva. 

There  is  reason  to  believe  that  the  diphtheria  bacillus  can  only 
act  on  the  conjunctiva  when  the  epithelium  has  been  injured, 
say  by  a  slight,  even  imperceptible  trauma,  or  by  a  previous 
inflammation. 

The  Xerosis  bacillus  must  not  be  mistaken  for  the  Klebs-Loeffler 
bacillus ;  the  only  reliable  method  of  distinguishing  one  from  the 
other  is  by  inoculation  in  animals. 

Microscopically  the  false  membrane  consists  of  a  fibrinous  net- 


CHAP.  III.]  THE    CONJUNCTIVA.  67 


work  contaiiiiiig  leucocytes,  a  few  epithelial  cells,  and  often  micro- 
organisms. In  the  so-called  croupous  cases  the  underlying  epithelium 
may  or  may  not  be  adherent  to  the  false  membrane,  but  even  in 
the  latter  event,  although  the  epithelium  separates  along  with  the 
membrane,  the  surface  left  is  smooth  and  becomes  covered  by 
regenerated  epithelium,  so  that  no  trace  of  scarring  occurs. 

On  the  other  hand,  in  the  severe  or  diphtheritic  cases  the  sub- 
mucous tissue  is  involved  in  the  exudation,  the  vessels  become 
compressed  by  it,  and  this  leads  to  necrosis.  When  the  dead  tissue 
has  been  cast  off  a  granulating  surface  is  exposed  which  heals  by 
cicatrisation.  These  are  true  granulations  in  the  surgical  sense, 
and  are  therefore  quite  different  from  the  "  granulations "  of 
trachoma. 

Etiology. — Membranous  conjunctivitis  in  all  degrees  of  severity 
is  met  with  for  the  most  part  in  children,  more  especially  in 
those  under  four  years  of  age.  The  Streptococcal  form  often 
follows  an  attack  of  measles  or  scarlatina,  and  is  frequently  accom- 
panied by  eczema  or  by  ulcers  of  the  skin  in  the  neighbourhood  of 
the  eyes. 

One  or  both  eyes  may  be  attacked.  It  is  an  acute  disease,  which 
occurs  sporadically  or  in  epidemics,  but  a  few  chronic  cases  have 
been  seen  to  last  for  many  months. 

Clinically,  the  mild  or  croupous  form  of  the  disease  can  readily 
be  distinguished  from  the  severe  or  diphtheritic  ;  hence  they  will 
be  described  separately,  with  the  understanding  that  the  real 
nature  of  each  case  can  only  be  decided  by  careful  bacteriological 
examination. 

Croupous  Conjunctivitis. — The  symptoms  are  those  of  catarrhal 
conjunctivitis,  to  which  in  a  few  days  is  added  the  appearance  of  a 
greyish  pellicle  on  the  palpebral  conjunctiva,  sometimes  also  on  the 
retro-tarsal  folds,  but  rarely  on  the  bulbar  conjunctiva.  The  false 
membrane  can  be  peeled  off,  leaving  a  mucous  surface  underneath 
which  may  or  may  not  bleed.  The  lids,  which  may  be  red  and 
swollen,  are  always  soft  and  easily  everted.  After  a  week  or  so  the 
second  or  secreting  stage  sets  in,  with  the  appearance  of  a  discharge, 
and  the  false  membrane  becomes  separated,  leaving  a  healthy 
mucous  surface  which  gradually  returns  to  its  normal  condition, 
without  any  trace  of  scarring.  Observations  with  reference  to 
corneal  complications  vary,  some  observers  never  having  seen  them, 


68  DISEASES    OF    THE    EYE.  [chap.  hi. 

while  others  have  noted  them  in  40  per  cent,  of  their  cases.  Con- 
stitutional symptoms  are  much  less  frequent  than  in  the  severe  or 
diphtheritic  variety  of  this  affection. 

Treatment. — In  the  first  stage  iced  compresses  or  Leiter's  tubes 
applied  to  the  lids,  with  antiseptic  cleansing  of  the  conjunctival 
sac.  No  caustic  should  be  used  in  this  stage,  as  it  is  apt  to  produce 
corneal  changes.  Sulphate  of  quinine  insufflated,  or  in  2  per  cent, 
solution,  is  praised  by  some  surgeons  as  a  useful  application  at  this 
period.  In  the  secreting  stage  nitrate  of  silver  applications  should 
be  made  in  the  usual  way. 

When  the  Klebs-Loeffler  bacillus  is  the  active  agent  antitoxin 
should  be  used.  Simple  instillations  into  the  conjunctival  sac,  with 
which  we  have  obtained  a  good  result,  may  suffice  in  these  mild 
cases.     (See  Treatment  of  Diphtheritic  Conjunctivitis.) 

Diphtheritic  Conjunctivitis. — There  is  no  more  serious  ocular 
disease  than  this,  for  it  may  destroy  the  eye  in  twenty-four  hours  ; 
while  in  severe  cases  treatment  is  almost  powerless.  Fortunately 
it  is  exceedingly  rare  in  these  countries. 

The  subjective  symptoms  of  its  initial  stage  are  similar  to  those 
of  blennorrhoeic  conjunctivitis,  but  severer,  especially  in  the  matter 
of  pain.  The  objective  symptoms  differ  from  those  of  blen- 
norrhcea,  in  that  the  lids  are  excessively  stiff,  owing  to  plastic  in- 
filtration of  the  sub-epithelial  and  deeper  layers  of  the  conjunctiva, 
while  the  surface  of  the  mucous  membrane  is  smooth,  and  of  a  grey- 
ish or  pale  buff  colour.  If  an  attempt  be  made  to  peel  off  some  of 
the  superficial  exudation  the  surface  underneath  will  be  found 
of  the  same  grey  colour,  not  red  and  vascular,  as  in  croupous  con- 
junctivitis. Ulcers  of  the  skin  covered  with  a  greyish  membrane 
are  often  present  on  the  eyelids  and  cheek,  or  round  the  nostrils 
or  lips,  and  the  preauricular  glands  are  enlarged.  This  stage  of 
infiltration  lasts  from  six  to  ten  days,  and  constitutes  the  period  of 
greatest  peril  to  the  eye  ;  for  while  it  lasts  the  nutrition  of  the 
cornea  must  suffer,  and  sloughing  of  that  organ  is  extremely  apt 
to  take  place.  Towards  the  close  of  the  first  stage  the  fibrinous 
infiltration  is  eliminated  from  the  eyelids,  and  the  conjunctiva 
gradually  assumes  a  red  and  succulent  appearance,  and  at  the 
same  time  a  purulent  discharge  is  established.  This  constitutes 
the  second  or  Uennorrhceic  stage.  A  third  stage  is  formed  by  cica- 
tricial alterations  in  the  mucous  membrane,  which  often  lead  to 


CHAP.  TIL]  THE    CONJUNCTIVA.  69 


symblepharon,  or  to  xerophthalmos  ;  so  that,  even  if  the  eye  escape 
corneal  danoers  in  the  first  and  second  stages,  others  almost  as 
serious  may  await  it  in  the  final  stage. 

Corneal  complications  are  most  likely  to  occur  in  the  first  stage, 
and  are  then  also  most  likely  to  prove  destructive  to  the  eye.  The 
earlier  they  appear  the  more  dangerous  are  they.  If  the  blennor- 
rhoeic  stage  come  on  before  corneal  complications  appear,  or  even 
before  an  ulcer  contracted  in  the  first  stage  has  advanced  far,  thev 
are  more  easily  controlled. 

In  the  third  stage  corneal  affections,  if  they  occur,  are  of  a  chronic 
nature  and  are  generally  accompanied  by  vascularisation. 

This  disease  is  nearly  always  combined  with  constitutional 
symptoms,  such  as  fever,  malnutrition,  albuminuria,  and  is  some- 
times fatal ;  but,  strange  to  say,  it  is  very  rarely  followed  by  para- 
lysis, even  of  accommodation.  It  has  seldom  been  observed  to 
follow  diphtheria  of  the  throat,  although  the  opposite  sequence  is 
not  uncommon. 

Treatment. — If  the  disease  be  due  to  the  Klebs-Loeffler  bacillus, 
antitoxin  serum  is  the  sovereign  remedy,  and  as  the  identifica- 
tion of  the  diphtheria  bacillus  takes  time,  any  presumption  of 
its  presence  should  be  acted  upon  without  delay.  The  injections 
may  be  given  under  the  skin  of  the  eyelids,  and  instillations  into 
the  conjunctival  sac  may  be  made  as  well.  In  streptococcal  cases 
anti-streptococcus  serum  may  be  used,  but  it  does  not  act  so  well 
as  the  diphtheria  antitoxin.  Precautions  should  of  course  be 
taken  to  avoid  the  transference  of  the  disease  to  other  persons.  In 
cases  caused  by  the  pneumococcus,  Romer's  pneumococcus  serum 
may  be  used.  These  remarks  also  apply  to  croupous  con- 
junctivitis. 

Local  treatment  in  the  first  stage  should  consist  in  cold  applica- 
tions and  antiseptics  ;  later  on,  warm  fomentations,  especially  if 
the  patient  finds  them  more  agreeable,  can  with  advantage  be 
substituted  for  the  cold.  In  the  secreting  stage  the  same  lines  of 
treatment  should  be  followed  as  in  catarrhal  conjunctivitis,  except 
that  greater  precaution  should  be  taken  in  using  nitrate  of  silver  ; 
the  greater  the  discharge  the  more  freely  it  may  be  applied.  Corneal 
ulcers  must  be  dealt  with,  whenever  they  arise,  in  the  same  way  as 
though  the  case  were  one  of  blennorrhoeic  conjunctivitis.  When 
the  purulent  discharge  ceases,  solutions  containing  soda  or  glycerine 


70  DISEASES    OF    THE    EYE.  [chap.  hi. 

may  be  prescribed  as  lotions  for  the  conjunctiva,  to  relieve  the 
xerophthalmos. 

Hay  Fever. — This  is  not  uncommon  among  the  better  classes  in 
these  countries,  although  it  is  rarely  seen  in  our  hospital  patients.  The 
symptoms,  in  those  liable  to  it,  appear  in  the  early  summer  each  year, 
and  disappear  again  in  the  course  of  six  weeks  or  two  months.  They 
consist  in  catarrh  of  the  nostrils,  accompanied  by  great  itching  of  them 
and  frequent  sneezing  ;  while  the  conjunctiva,  especially  in  the  lower 
fornix,  becomes  somewhat  hypersemic,  and  there  is  lacrimation.  There 
is  excessive  itching  of  the  eyes,  which  renders  the  patient  most  wretched, 
and  compels  him  to  rub  his  eyes  violently.  There  is  photophobia.  The 
respiratory  tract  may  become  involved,  with  some  bronchitis  and  asthma, 
and  general  malaise  and  elevation  of  temperature  are  present.  Some- 
times the  eyes  alone  are  affected.  There  is  no  tendency  to  corneal  com- 
plications. Dviring  an  attack  the  eosinophile  cells  in  the  conjunctival 
sac  are  increased  in  number  as  in  Spring  Catarrh. 

Treatment  is  of  no  avail  in  preventing  the  annual  recurrence  of  the 
affection,  nor  is  it  of  much  use  in  alleviating  the  attack.  No  strong  local 
application  should  be  employed.  Weak  collyria,  or  ointments,  of  sulphate 
of  zinc,  or  copper,  boric  acid,  or  sublimate,  etc.,  may  be  tried.  Adrenaline, 
cocaine,  or  holocaine  eye  drops  (2  per  cent.)  afford  the  best  relief.  Dark 
glasses  should  be  worn. 

Dunbar's  hay  fever  serum,  called  pollantine,  has  been  used  with  benefit 
in  some  cases. 

Trachoma  (rpaxts,  rough),  Granular  Conjunctivitis,  or  Granu- 
lar Ophthalmia  (also  called  Egyptian  Ophthalmia  and  Military 
Ophthalmia). — In  this  disease,  in  addition  to  the  usual  appearances 
of  simple  conjunctivitis,  there  are  developed  translucent  greyish 
or  pinkish-grey  bodies  about  the  size  of  the  head  of  a  pin  or  larger, 
situated  in,  and  close  to  the  fornix  conjunctivae,  chiefly  of  the  upper 
lid.  They  also  occur  on  the  tarsus,  in  the  lower  fornix,  and  some- 
times on  the  plica  semilunaris,  but  are  very  rarely  met  with  on  the 
bulbar  conjunctiva.  The  tarsal  growths  are  smaller,  flatter,  and 
yellower  in  colour  than  those  seen  in  the  fornix.  These  bodies 
are  the  trachoma  bodies  or  granulations,  or  "  sago  grains,"  they 
somewhat  resemble  the  follicles  of  follicular  conjunctivitis,  except 
that  they  are  paler,  more  irregular  in  size  and  less  apt  to  occur  in 
rows. 

Microscopically  they  exhibit  the  structure  of  hjmplioid  follicles, 
and  consist  of  an  outer  zone  of  small  lymphocytes  and  a  central 
mass  of  larger  endothelioid  cells,  amongst  which  some  very  large 
cells  are  found  with  irregular  processes  and  cell-inclusions.     These 


CHAP.  III.]  THE    CONJUNCTIVA.  71 


are  the  so-called  "  trachoma  cells  "  or  "  corpuscle  cells  "  ;  they 
are  supposed  to  be  phagocytes  or  enlarged  connective  tissue  cells, 
and  have  even  erroneously  been  taken  for  protozoa,  but  since  they 
exist  in  normal  lymph  follicles  in  other  places,  they  are  not  in  any 
sense  specific.  The  cellular  elements  of  the  follicle  lie  in  the  meshes 
of  a  delicate  reticulum,  the  follicle  itself  being  surrounded  by  a 
vascular  network  and  a  more  or  less  defined  capsule. 

The  unevenness  of  the  conjunctival  surface  is  still  further  in- 
creased by  a  luxuriant  formation  of  fapillce  due  to  the  folding  of 
the  inflamed  and  hypertrophied  mucous  membrane,  which  also 
leads  to  the  development  of  microscopic  glands  and  later  on  of 
small  cysts.  The  latter  are  met  with  in  the  furrows  between  the 
papillae,  or  they  may  be  produced  by  solid  downgrowths  of  epithe- 
lium, which  become  softened  in  the  centre.  The  follicles  ultimately 
become  absorbed,  or  soften,  and  extrude  their  contents  on  the 
surface.  In  any  case  their  disappearance  is  followed  by  the 
development  of  fibrous  cicatricial  tissue,  from  the  shrinking  of 
which  various  complications,  which  will  be  mentioned  later  on, 
ensue.  The  tarsus  may  be  involved  in  the  inflammation,  and  in 
many  cases  a  vascular,  richly  cellular  layer  called  pannus  forms 
in  the  cornea  between  the  epithelium  and  Bowman's  membrane. 

Etiology  and  Cause. — There  can  be  no  doubt  but  that  this  disease 
is  contagious,  and  that  it  is  the  result  of  a  specific  cause,  the  nature 
of  which  is  still  unknown.     Peculiar 
cell-inclusions   have    been   found    in 
the    epithelial    cells,   in   smear    pre- 
parations of  the  secretion  or  of  the 
scrapings  taken  from  recent  untreated      ^ 
cases.     The  appearance   which  they 

present  varies    in  different    stages. 

t,.       oo  /f  •    •      1    J         •  Fig.    38.— Epithelial      cell 

bis.  38  (from   an  ormmal  drawmg,  ,        ^,          •       -•        t    ^  ^^ 

^         ,  ,  from  the  conjunctiva  ot  a  case 

for  which    we    are    indebted  to  the       of  trachoma. 

kindness  of  Professor  Greeff ,  one  of         («)  ceii  inclusions,  forming  a  duster 

the    discoverers     of     these    Cell-inclu-         in  the  protoplasm  of  the  cell,  dose  to 

the  nudeus  (6),  (r)  isolated  granules. 

sions)    illustrates    one    of   the   most 

characteristic  stages.  The  nature  of  these  fine  granules  has  not, 
however,  been  ascertained,  and  their  causative  relation  to  granu- 
lar ophthalmia  has  not  been  established.  Unfortunately  it  has 
not  yet  been  possible  to  isolate  or  cultivate   them,  and  hence  no 


72  DISEASES    OF    THE    EYE.  [chap.  hi. 

pure  cultures  have  been  obtained  with  which  to  perform  experi- 
ments. More  recently,  similar  cell  inclusions  have  been  found  in 
non-gonococcal  forms  of  ophthalmia  neonatorum  (and  even  in  the 
normal  conjunctiva),  and  for  this  and  other  reasons  the  theory  has 
been  advanced  that  these  minute  bodies  are  an  involution  form  of 
the  gonococcus.  They  have  also  been  found  in  cases  of  gonorrhoea, 
both  in  males  and  females,  but  it  is  still  uncertain  whether  any  real 
relation  exists  between  this  disease  and  granular  ophthalmia.  By 
some  these  cell-inclusions  are  held  to  be  merely  products  of  nuclear 
degeneration. 

The  histological  changes  are  not  peculiar  to  this  disease  alone 
— the  papillary  hypertrophy  is  well  seen  in  chronic  blennorrhoea, 
for  instance — and  even  lymph  follicles  occur  from  other  causes  ; 
for  'example,  from  atropine  irritation  and  in  tuberculosis.  In- 
fection occurs  only  by  transference  of  the  secretion  from  one  eye 
to  the  other  by  means  of  fingers,  towels,  handkerchiefs,  etc.  Hence 
slovenly  personal  habits,  overcrowding  of  dwellings,  schools,  or 
barracks  help  the  disease  to  spread  from  one  individual  to  another 
when  it  once  gains  a  foothold  in  a  country.  A  great  deal,  however, 
remains  to  be  learned  as  to  the  manner  in  which  contagion  takes 
place.  The  infectiousness  of  chronic  cases  cannot  be  very  great,  for 
nurses  and  doctors  rarely,  if  ever,  become  infected  by  their  patients. 
Neither  do  we  see  trachoma  patients  infecting  surgeons,  nurses,  or 
other  patients  in  the  hospitals  in  Ireland,  where  the  disease  is  so 
prevalent.  Were  the  infectiousness  of  the  disease  very  great,  even 
the  precautions  taken  in  a  well-ordered  hospital  against  contagion 
would  hardly  be  sufficient  to  prevent  such  an  occurrence  occasionally. 
Moreover,  inoculation  experiments  do  not  always  succeed. 

Amongst  the  better  classes,  both  here  and  elsewhere,  the  disease 
is  very  uncommon.  Even  the  poor  in  high,  dry,  mountainous 
countries  are  almost  free  from  it,  so  that,  probably,  the  atmospheric 
conditions  play  some  part  in  the  etiology. 

Some  hold  that  the  affection  is  dependent  on  constitutional 
disease,  such  as  scrofula,  tuberculosis,  syphilis,  etc.  ;  but  we  cannot 
endorse  this  view.  No  doubt  many  of  these  patients  are  anaemic 
and  out  of  health,  but  this  is  due  to  the  moping  habits  they  contract, 
and  the  little  open-air  exercise  they  take  in  consequence  of  their 
semi-blindness. 

The  effect  of  race  as  a  predisposing  cause  is  doubtful.     Jews 


CHAP.  III.]       ^  THE    CONJUNCTIVA.  73 

are  said  to  be  peculiarly  liable  to  the  disease,  but  it  must  be  re- 
marked that  in  them  as  in  others  it  only  occurs  amongst  the  very 
poor. 

Trachoma  generally  attacks  both  eyes  and  is  an  extremely 
chronic  affection.  An  acute  form  is  described,  which,  however,  must 
be  very  rare,  as  it  is  practically  non-existent  in  Ireland,  although 
the  chronic  variety  of  the  disease  is  so  common  here. 

Acute  Trachoma,  or  Acute  Granular  Ophthalmia. — The  symptoms 
are  those  of  a  more  or  less  acute  purulent  ophthalmia,  associated 
with  the  characteristic  appearances  of  trachoma.  The  acute  symp- 
toms are  really  due  to  an  additional  infection  by  the  gonococcus  or 
Koch- Weeks  bacillus. 

Treatment. — In  the  early  stage  the  treatment  is  the  same  as  for 
acute  blennorrhoea,  while  at  a  later  period  the  same  methods  are 
adopted  as  in  chronic  trachoma. 

Chronic  Trachoma,  or  Chronic  Granular  Ophthalmia. — In  the 
early  stage,  which  may  pass  unnoticed,  this  disease  is  often  un- 
accompanied by  inflammation,  and  is  then  unattended  by  any  dis- 
tressing symptoms,  except  that  the  eye  may  be  more  easily  irritated 
by  exposure,  or  more  readily  wearied  by  reading  or  near  work.  At 
this  period  the  conjunctiva  will  be  found  free  from  injection  except 
perhaps  at  the  inner  and  outer  corners  of  the  palpebral  portion  of  the 
upper  lid,  where  there  may  be  a  slight  roughness  or  some  small 
follicles.  But  later  on  greyish-white  semi-transparent  trachoma 
bodies,  of  the  size  of  a  rape-seed  and  less,  may  be  found  in  the  upper 
fornix,  sometimes  only  by  careful  examination,  or  again,  they  may 
be  seen  disseminated  over  the  conjunctival  surface  of  the  upper  lid, 
and  protruding  from  it.  Gradually  these  trachoma  bodies  or  granu- 
lations give  rise  to  a  more  or  less  active  vascular  reaction,  attended 
with  swelling  of  the  papillae  and  purulent  discharge — in  short,  slight 
blennorrhoea.  This  is  the  stage  of  progression  (Fig.  39).  The 
patients  then  begin  to  be  more  inconvenienced,  owing  to  the  discharge 
which  obscures  their  vision,  to  sensations  of  weight  in  the  lids  and  of 
foreign  bodies  in  the  eye,  and  to  partial  ptosis,  which  gives  them  a 
sleepy  look.  This  is  generally  the  earliest  stage  at  which  we  see  the 
disease.  The  enlarged  papillae  often  grow  to  a  great  size,  completely 
hiding  the  granulations,  constituting  what  is  known  as  the  "  papillary 
form  "  of  the  disease.  In  this  stage  the  granulations  may  become 
absorbed,  and  the  disease  undergo  cure  ;    but  more  commonly  it 


74  DISEASES    OF    THE    EYE.  [chap.  hi. 

makes  further  progress.  Fresh  granulations  appear,  while  the 
old  ones  increase  in  size  and  undergo  a  peculiar  gelatinous  change. 
They  then  often  become  confluent,  leaving  only  here  and  there  an 
island  of  vascular  mucous  membrane.  Sometimes  the  trachoma 
bodies  are  very  small,  and  present  the  appearances  of  minute  yellowish 
dots,  and  in  this  form  they  are  not  always  easily  found. 

Gradually  the  follicles  become  absorbed,  or  more  rarely  their 
contents  are  expelled,  and  the  connective  tissue  proliferates  so  as 
to  cause  more  or  less  extensive  scarring  of  the  conjunctiva.  This 
constitutes  the  cicatricial  stage  of  the  disease.   The  scarring  frequently 


/  /.  .A 


Fig.   39. — Granular  ophthalmia  ;  Fig.  40. — Granular  ophthalmia ; 

progressive  stage.  cicatricial  stage,  with  pannus  and 

trichiasis. 

presents  a  reticulated  appearance,  and  in  many  cases  assumes  the 
form  of  a  white  line  situated  in  the  subtarsal  sulcus.  Fig.  40. 

The  tarsus  may  undergo  fatty  or  hyaline  degeneration  or  be- 
come hypertrophied,  while  the  diseased  conjunctiva  on  the  inner 
surface  of  the  lid  causes  curving  of  the  tarsus  with  entropion  and 
distortion  of  the  bulbs  of  the  eyelashes,  followed  by  irregular  grou'th 
of  the  latter,  with  resulting  trichiasis  and  distichiasis.  These 
changes  are  represented  in  Fig.  41.  The  bulbar  conjunctiva  may 
become  atrophied,  cease  to  secrete,  and  become  dried,  giving  rise 
to  xerosis.  In  consequence  also  of  the  shrinking  of  the  conjunctiva, 
the  fornices  may  become  partially  or  wholly  obliterated,  thus  causing 
symblepharon  (adhesion  of  the  eyelids  to  the  eyeball). 

The  great  danger  of  granular  ophthalmia  lies  in  the  complications 
which  may  attend  it,  or  which  follow  in  its  wake  ;  the  former  are 
pannus,  ulcers  of  the  cornea,  and  severe  purulent  conjunctivitis, 
while  the  latter  are  the  distortions  of  the  lids  and  eyelashes  just 
referred  to. 


CHAP,    III. 


THE    CONJUNCTIVA. 


75 


Fig.   41.   {Scemisch.) 
Section  of  a  trachomatous  eyelid. 

a.  Muscle  :,  h  h,  Tarsus  having  undergone 
fatty  degeneration  ;  c,  Atrophied  Meibomian 
Grland  ;  d  d,  Hypertrophied  Papilla  ;  e,  Cica- 
tricial Tissue  in  the  conjunctiva  ;   /,  Tarsus. 


Pannus    {Lat.    a    cloth   rag) 
presents  the  appearance  (Fig.  40) 
of    a    superficial  vascularisation 
of  the  cornea,  with  more  or  less 
diffuse  opacity,  and  often   small 
infiltrations.      The   new    vessels 
can  be  seen  to  grow  in  from  the 
conjunctiva.     It  invariably  com- 
mences in  the  upper  portion  of 
the  cornea,  extending  generally 
over    the    upper   half,   and    fre- 
quently remains  confined  to  this 
region.     But  in  many  cases,  at  a 
later  stage,  it  extends  over  the 
whole    surface    of   the    cornea  ; 
this  latter  occurrence  often  takes 
place  almost  suddenly,  and  the 
vascularisation    and    opacity 
sometimes  become  so  intense  as  to  present  quite  a  fleshy  appear- 
ance, completely  hiding  the   corresponding  part  of  the  iris  from 
view.      Histologically,   pannus  consists   of   a   new   growth,   which 
is  extremely  rich  in  cells,  and  which   closely  resembles  the  con- 
junctiva when    occupied    with    confluent    granulations.      It  is  in 
fact    a    vascular    granulation    tissue,    which    grows    in   from  the 
limbus,  and  is  situated  between  the  corneal  epithelium  and  Bow- 
man's   layer.     After    a  length    of    time   Bowman's  layer  becomes 
destroyed  in  places,  and  then  the  cellular  infiltration  gains  access 
to   the   true   cornea,   and   gives   rise  to  permanent   changes  in  its 
transparency  and  curvature.     In  some  bad  cases  of  old-standing 
pannus  the  latter  undergoes  a  connective-tissue  change.     It  then 
becomes  smooth  on  the  surface,  and  the  vessels  almost  disappear, 
so  that  the  cornea   is  covered  with   a  thin   layer   of   connective 
tissue,    which  obstructs  the  passage  of  light  and    is    not    capable 
of  cure.      Small   ulcers,    and   sometimes  white  deposits,  are  liable 
to    form    at    the   lower   edge   of   the  pannus  near  the  centre   of 
the   cornea.      These    deposits    are   superficial,   and   can    be    easily 
scraped  off. 

Another  result  of  pannus,  sometimes  seen,  is  a  bulging  or  staphy- 
lomatous  condition  of  the  cornea,  the  tissues  of  which  have  become 


76  DISEASES    OF    THE    EYE.  [chap.  m. 


so  altered  and  weakened  that  they  give  way  before  the  normal 

intra-ocular  tension. 

A  pannns  in  which  as  yet  there  is  no  connective-tissue  alteration, 
and  where  there  is  no  staphylomatous  bulging,  is  capable  of  under- 
going cure  without  leaving  any  opacity  behind,  except  that  which 
may  be  due  to  ulcers  that  have  been  present. 

Pannus  is  generally  accompanied  by  photophobia  and  ciliary 
neuralgia.  It  may  come  on  at  any  stage  of  the  disease,  and  causes 
defective  vision,  in  proportion  to  the  degree  and  extent  of  the 
opacity.     Severe  pannus  is  liable  to  induce  iritis. 

It  was  for  a  long  time  held  that  pannus  was  due  to  mechanical 
irritation,  caused  by  the  rough  palpebral  conjunctiva  ;  but  even 
severe  pannus  is  often  seen  with  a  comparatively  smooth  conjunctiva, 
while  with  a  truly  rough  conjunctiva  the  cornea  is  frequently  perfectly 
clear.  There  can  now  be  little  doubt  that  pannus  is  analogous  to 
the  granular  disease  in  the  conjunctiva.  It  is,  in  fact,  the  same 
disease  modified  by  reason  of  the  different  tissue  in  which  it  is 
situated,  this  different  tissue  being  itself  a  modification  of  the  con- 
junctiva ;  and  microscopic  examination  of  the  bulbar  conjunctiva 
shows  that  it  is  infiltrated  though  apparently  unaffected  on  clinical 
inspection.  So  that  pannus  is  a  direct  extension  of  the  disease  to 
the  cornea.  Visible  follicles  in  the  bulbar  conjunctiva  are  extremely 
rare ;  we  have  however  seen  a  neglected  case  in  which  the  patient 
refused  all  treatment,  and  not  only  were  there  follicles  on  the  bulbar 
conjunctiva,  but  also  on  the  cornea. 

Prognosis. — At  any  period  prior  to  cicatrisation  of  the  con- 
junctiva an  attack  of  purulent  blennorrhoea  is  liable  to  come  on. 
If  not  too  severe,  this  may  result  in  a  cure  by  absorption  of  the 
trachoma  bodies,  and  should  not  be  checked.  If,  however,  the 
attack  be  very  severe,  the  eye  runs  dangers  similar  to  those  of  an 
ordinary  attack  of  purulent  conjunctivitis.  These  dangers  are  less 
the  more  complete  and  the  more  intense  the  pannus. 

On  the  whole,  if  the  disease  come  under  care  at  an  early  period, 
and  if  treatment  be  carried  out  strictly,  vision  will  be  retained  in 
a  majority  of  cases,  although  a  radical  cure  may  be  difficult  or 
impossible.  Patients  require  to  be  under  constant  treatment  for 
long  periods,  and  the  very  lengthened  time,  and  steady  continuous 
treatment  needed  for  a  cure,  are  probably  the  main  obstacles  to 
that  cure.     In  most  cases  of  chronic  granular  ophthalmia,  attend- 


OHAP.  iii.l  THE    CONJUNCTIVA.  77 

ance  three  times  a  week  for  a  year  will  be  required,  to  effect  any- 
thing that  can  be  called  a  cure.  The  common  experience  is  that 
patients  attend  for  some  weeks,  and  then,  being  very  considerably 
relieved  of  their  distressing  symptoms,  and  finding  their  sight  vastly 
impi'oved,  they  cease  attendance  long  before  the  disease  has  been 
eliminated,  to  return  after  a  brief  interval  with  a  condition  of  things 
as  bad  as,  if  not  worse  than,  before.  It  is  therefore  desirable  at  the 
very  outset  of  treatment  to  explain  the  tedious  and  dangerous 
nature  of  the  ailment  to  each  patient. 

Treatment. — The  aim  of  this  is  to  bring  about  the  absorption 
or  disappearance  of  the  trachoma  bodies  with  the  greatest  possible 
despatch,  in  order  to  prevent  the  destruction  of  the  mucous  mem- 
brane, to  which  they  tend. 

The  methods  of  treatment  on  which  most  reliance  is  placed, 
either  separately  or  in  combination,  are  : — the  application  of  caustics, 
mechanical  or  operative  procedures,  and  the  use  of  jequirity.  In 
conjunction  with  these,  cases  attended  by  inflammatory  symptoms 
and  discharge  must  be  treated  according  to  the  general  principles 
indicated  on  p.  54,  and  antiseptic  lotions  or  sterilised  fluids  should 
be  used  to  keep  the  conjunctiva  free  from  discharge,  and  a  simple 
ointment  should  be  applied  to  the  eyelids  at  night.  Complications 
may  require  to  be  dealt  with  by  special  methods.  Attention  should 
be  paid  to  the  general  health  of  the  patient,  and  to  the  hygienic 
conditions  under  which  he  lives,  and  finally  prophylactic  measures 
should  be  taken  to  prevent  the  spread  of  the  disease  to  other  members 
of  the  household  or  community. 

I.  Caustics. — No  caustic  application  should  be  made  with  the 
object  of  directly  destroying  the  trachoma  bodies,  for  this  can  be 
done  only  at  the  expense  of  the  mucous  membrane  around  them. 
The  most  useful  caustics  are  nitrate  of  silver  and  sulphate  of  copper. 
For  chronic  cases,  with  but  little  swelling  of  the  papillae  (blen- 
norrhoea),  and  with  little  or  no  cicatrisation,  the  best  application 
is  the  solid  sulphate  of  copper  lightly  applied  to  the  conjunctiva, 
especially  at  the  fornix  ;  but  when  there  is  considerable  papillary 
swelling  or  discharge,  a  2  per  cent,  solution  of  nitrate  of  silver, 
or  a  light  application  of  mitigated  silver  nitrate,  neutralised  with  salt 
solution,  is  to  be  preferred,  Should  there  be  ulcers  on  the  cornea,  or 
much  inflammatory  irritation  of  the  eye,  sulphate  of  copper  should 
not  be  applied  to  the   conjunctiva.     An  interval  of  twenty-four 


78  DISEASES    OF    THE    EYE.  [chap.  in. 


hours  at  least  should  be  allowed  to  elapse  between  each  application, 
whether  of  sulphate  of  copper  or  nitrate  of  silver,  and  cold  sponging 
for  fifteen  minutes  should  be  employed  immediately  after  the 
application.  A  change  of  treatment  will  be  occasionally  required, 
even  if  the  remedy  first  used  answer  well  in  the  beginning,  and  one 
or  other  of  the  following  can  be  adopted.  Pure  liquefied  carbolic 
acid  has  been  used  with  good  result,  but  we  have  no  experience  of 
it.  It  is  applied  w^ith  a  camel's-hair  pencil,  and  the  excess  washed 
off  with  plain  water.  Solution  of  sublimate,  1  in  1000,  or  even  1  in 
500,  may  be  applied  with  lint  or  cotton-wool  to  the  everted  con- 
junctiva with  some  pressure  and  rubbing.  Alum,  in  the  solid  form, 
is  also  used  in  the  same  way,  and  in  the  same  class  of  cases,  as 
sulphate  of  copper.  Ointments  of  copper  sulphate  (J  to  1  per  cent.) 
or  copper  citrate  (10  per  cent.)  are  sometimes  employed,  but  they 
are  not  so  active  as  the  crystal.  Sulphate  of  zinc  is  indicated  if, 
as  is  sometimes  the  case,  angular  conjunctivitis  be  present  as  a 
complication. 

2.  Mechanical  and  Operative  treatment. — The  best  of  these  pro- 
cedures are  :  expression,  which  aims  at  evacuating  the  granulations, 
and  excision  of  the  fornix,  by  which  those  situated  in  that  region 
are  removed  en  masse.  Expression  was  formerly  practised  by  the 
late  Sir  William  Wilde  of  Dublin,  who  squeezed  out  the  granulations 
between  the  thumb  nails.  The  present-day  proceeding  is  carried 
out  aseptically  by  means  of  Knapp's  roller  forceps,  or  better  still 


Fig.  42. 


with  Graddy's  forceps  (Fig.  42).  Similar  but  smaller  instruments 
are  also  made  for  the  purpose  of  reaching  the  inner  and  outer  angles 
of  the  lids,  where  it  is  difficult  to  apply  the  larger  ones.  The  opera- 
tion is  very  painful,  and  general  anaesthesia  may  be  necessary. 
The  retro-tarsal  fold  of  the  everted  lower  or  upper  lid  is  grasped  as 
far  back  as  possible  between  the  blades  of  the  instrument,  com- 
pressed and  drawn  upon,  and  in  this  way  the  trachomatous  tissue 
is  squeezed  out  with  little  or  no  laceration  of  the  conjunctiva.     The 


CHAP.  III.]  THE    CONJUNCTIVA.  79 

instrument  has  to  be  re-inserted  and  a  neighbouring  part  of  the 
conjunctiva  treated  in  the  same  way,  and  so  on,  until  the  whole 
conjunctiva  of  each  affected  eyelid  has  been  operated  on.  The 
four  eyelids  may  be  manipulated  at  one  sitting,  and  the  evacuation 
should  be  as  complete  as  possible.  Particular  care  should  be  taken 
to  reach  the  part  of  the  conjunctiva  which  is  hidden  under  the 
commissures.  Some  cases  are  immediately  and  permanently  cured 
by  this  operation  ;  while  others,  although  greatly  benefited,  will 
still  require  further  routine  treatment  with  local  remedies.  Ex- 
pression is  indicated  only  where  trachomatous  substance  can  be 
pressed  out.  Our  experience  with  this  method  leads  us  to  regard 
it  as  a  very  useful  one  for  the  acceleration  of  the  cure  of  recent  cases, 
some  of  which  we  have  seen  to  recover  with  scarcely  any  trace 
of  scarring.  We  often  apply  silver  nitrate  immediately  after 
expression. 

Excision  of  the  upper  fornix  of  the  conjunctiva  also  renders  great 
service.  This  method  shortens  the  treatment  of  all  forms  of  the 
disease;  the  granulations  in  the  palpebral  conjunctiva,  although 
not  directly  included  in  the  operation,  disappear  quickly,  and 
recurrences  of  the  disease  are  rarer  than  by  other  methods  of  treat- 
ment. The  resulting  linear  cicatrix  has  no  serious  consequence, 
and  is  as  nothing  when  compared  w4th  the  extensive  cicatricial 
degenerations  of  the  whole  mucous  membrane  which  the  operation 
is  calculated  to  prevent.  In  order  to  avoid  cicatricial  contraction 
care  should  be  taken,  during  the  operation,  that  sufficient  mucous 
membrane  be  left  to  completely  cover  the  globe  when  the  patient 
looks  down.  Supplemental  treatment  with  the  customary  local 
applications  is  employed  until  the  cure  is  obtained.  We  find  this 
an  exceedingly  useful  procedure  in  some  cases.  When  the  tarsus  is 
much  thickened,  partial  or  complete  excision,  including  the  con- 
junctiva over  it,  should  be  performed. 

Other  mechanical  methods  are  :  scarification,  scraping  with  a 
sharp  spoon,  brushing  the  conjunctiva  with  a  metallic  or  stiff  tooth- 
brush, followed  by  a  rubbing  with  (1  in  500)  solution  of  corrosive 
sublimate,  electro-cautery,  and  electrolysis. 

3.  Infusion  of  Jequirity  {Abrus  precatorius,  Paternoster  Bean) 
is  made  by  macerating  154  grains  of  the  decorticised  jequirity  seeds 
in  16  oz.  of  cold  water  (a  3  per  cent,  infusion)  for  twenty-four  hours. 
Twice  a  dav  for  three  davs  the  lids  are  everted,  and  the  infusion 


80  DISEASES    OF    THE    EYE.  [chap.  hi. 


thoroughly  rubbed  into  the  conjunctiva  with  a  bit  of  lint.  The 
result  is  a  severe  conjunctivitis  with  a  somewhat  croupous  tendency 
(even  the  cornea  being  often  hidden  by  the  false  membrane),  accom- 
panied by  great  swelling  of  the  eyelids,  much  pain,  and  considerable 
constitutional  disturbance,  rapid  pulse,  and  temperature  of  100°, 
or  more.  At  first  the  pannus  becomes  more  visible,  but  as  the 
inflammation  subsides,  it  diminishes  or  even  disappears,  while  com- 
plete cure  of  the  granular  ophthalmia  itself  is  rarer.  Iced  compresses 
to  the  eyelids  may  be  used  during  the  inflammation.  A  fresh 
infusion  (not  more  than  seven  days  old)  must  be  employed  in  order 
to  secure  the  best  reaction.  We  find  the  remedy  harmless,  if  not 
always  successful ;  but  a  good  many  cases  are  on  record  where 
violent  diphtheritic  conjunctivitis,  followed  by  blennorrhoea  of  the 
conjunctiva,  and  by  more  or  less  extensive  ulceration  of  the  cornea, 
and  even  complete  loss  of  the  eye,  were  produced.  We  have, 
occasionally,  seen  small  superficial  ulcers  form  on  the  cornea  without 
further  injury.  The  presence  of  a  purulent  discharge  from  the 
conjunctiva  is  a  contra-indication  for  this  treatment,  which  is  then 
liable  to  increase  the  intensity  of  the  blennorrhoea  in  a  dangerous 
degree.  Cases  where  there  is  little  or  no  papillary  SAvelling,  but 
merely  dry  trachoma  with  pannus,  are  the  most  suitable  for  its  use, 
and  we  cannot  recommend  it  too  highly  in  these  cases.  Very  rapid 
and  effective  cures  of  the  severest  pannus  sometimes  follow  the  use 
of  this  remedy  in  properly  selected  cases.  But  the  presence  of  well- 
marked  pannus  of  the  cornea  without  ulceration  is  the  only  thing 
that  can  render  the  employment  of  jequirity  justifiable,  and  in 
addition  to  this,  as  stated,  the  conjunctiva  should  be  free  from 
blennorrhoea. 

The  occurrence  of  acute  dacryocystitis  is  said  to  form  an  un- 
pleasant complication  of  the  jequirity  treatment,  even  in  cases  in 
which  the  sac  was  previously  quite  normal ;  but  we  have  never 
seen  it  to  occur. 

In  our  opinion  the  danger  of  jequirity  ophthalmia  can  be  mini- 
mised considerably  by  taking  care,  when  beginning  the  treatment, 
to  allow  twenty-four  hours  to  elapse  before  making  a  second  appli- 
cation. One  can  then  gauge  the  degree  of  reaction,  which  is  liable 
to  vary  with  different  infusions  or  Avith  the  idiosyncrasy  of  the 
patient.  As  a  matter  of  fact,  we  have  seen  one  patient  who  was 
absolutely  immune  to  jequirity. 


CHAP.  III.]  THE    CONJUNCTIVA.  81 

Jequiritol,  the  active  principle  of  jequirity,  dissolved  in  glycerine 
and  standardised  experimentally,  is  sometimes  used  instead  of 
jequirity.  We  have  not  found  it  as  effective  as  jequirity,  and  it  has 
the  great  disadvantage  in  hospital  work  of  being  very  much  more 
expensive. 

After  the  subsidence  of  the  jequirity  inflammation  some  of  the 
local  remedies,  above  referred  to,  should  be  regularly  applied  for 
the  purpose  of  completing  the  cure  of  the  conjunctival  condition. 

4.  Treatment  of  complications. — Where  pannus  is  present,  an 
occasional  drop  of  atropine  should  be  instilled,  in  order  to  control 
the  tendency  to  iritis  ;  but  pannus  in  itself  requires  no  special  treat- 
ment unless  it  persists  after  the  conjunctival  disease  has  entered 
the  cicatricial  stage,  when,  as  stated  above,  jequirity  is  of  service. 

The  operation  of  fefitomy  may  also  be  performed  for  pannus. 
It  consists  in  the  excision  of  a  portion  of  the  conjunctiva,  about 
5  mm.  broad,  around  the  corneal  margin.  Destruction  of  the 
vessels  with  the  actual  cautery  we  have  also  found  to  do  good  in  the 
treatment  of  pannus. 

Ulcers  of  the  cornea,  if  small,  require  no  additional  treatment 
beyond  atropine  ;  but  if  severe  must  be  dealt  with  accordingly. 
(See  chap,  v.)  Sometimes  small  white  spots  resembling  lead  de- 
posits form  in  the  centre  of  the  cornea  ;  they  are  quite  superficial, 
and  can  be  easily  removed  with  the  point  of  a  knife. 

Diplobacillary  conjunctivitis  is  not  a  very  uncommon  complica- 
tion of  trachoma,  but  when  it  occurs  the  patients  do  not  always 
present  the  well-know^n  appearances  of  angular  conjunctivitis.  In 
such  cases  sulphate  of  zinc  relieves  the  acute  symptoms  considerably. 

If  the  upper  lid  be  tightly  pressed  on  the  globe,  as  it  sometimes 
is,  the  physiological  lid-pressure  varying  in  different  individuals, 
an  impediment  is  offered  to  the  cure  by  any  method,  and  pannus 
is  promoted.  It  is  then  necessary  to  relieve  the  pressure  by  a 
canthoplastic  operation.     (See  chap,  xix.) 

The  treatment  of  xerophthalmia,  entropion,  and  such-like  sequelse 
is  described  under  their  respective  headings. 

Opinions  differ  as  to  the  value  of  the  treatment  of  trachoma 
by  X-rays,  radium,  and  high-frequency  currents.  Carbon  dioxide 
snow  is  also  being  used  at  present. 

In  addition  to  the  local  treatment  it  is  of  great  importance  that 
the  hygienic  surroundings  of  patients  suffering  from  granular  oph- 
6 


82  DISEASES    OF    THE    EYE.  [cnxv.  in. 

thalmia  be  seen  to,  and  that  they  be  obliged  to  spend  a  considerable 
time  daily  in  the  open  air. 

As  regards  Proj)hijlaxis,  patients  should  be  warned  of  the  danger 
of  infecting  others.  They  should  sleep  by  themselves  in  well- 
ventilated  rooms,  observe  habits  of  cleanliness,  and  have  separate 
towels,  etc.  Schools  and  public  institutions  should  be  inspected, 
and  if  there  be  any  cases  of  granular  ophthalmia  present,  an  ex- 
amination should  be  made  of  all  the  inmates,  and  all  persons  affected 
with  the  disease  as  well  as  suspicious  cases  should  be  isolated. 

Follicular  Conjunctivitis. — This  is  characterised  by  a  catarrhal 
inflammation  of  a  mild  type,  to  which  is  added  the  presence  in  the 
conjunctiva  of  small  round  greyish  or  yellowish-pink  follicles  the 
size  of  a  pin's  head,  which  disappear  completely  as  the  process  passes 
off,  leaving  the  mucous  membrane  as  healthy  as  they  found  it.  The 
follicles  are  situated  chiefly  in  the  lower  fornix  of  the  conjunctiva, 
and  may  be  discovered  by  e version  of  the  lower  lid,  when  they  will 
be  seen  arranged  in  rows  parallel  to  the  margin  of  the  lid.  Whether 
they  are  easily  discovered  or  not  depends  on  their  size  and  number, 
and  on  the  amount  of  co-existing  hyper?emia  or  chemosis  of  the 
conjunctiva. 

Follicular  conjunctivitis  usually  attacks  both  eyes,  and  is  a 
tedious  affection,  lasting  often  for  months.  It  is  met  with  chiefly 
in  children,  and  most  frequently  in  schools.  Systematic  examina- 
tions of  the  conjunctiva  in  schools  have  shown  that  a  very  large 
number  of  the  children  have  follicles  in  the  lower  fornix,  and 
occasionally  they  may  be  seen  in  the  upper  lids  towards  the  angles. 
In  some  cases  post-nasal  adenoids  are  associated  with  them.  The 
conjunctiva  is  otherwise  normal,  and  in  these  cases  the  follicles 
produce  no  irritation  or  distress  of  any  kind.  To  this  condition  the 
name  "  Folliculosis  "  is  sometimes  given,  and  it  is  believed  that 
it  renders  the  eye  more  liable  to  catarrhal  infection.  When  this 
occurs,  follicular  conjunctivitis  is  the  result. 

The  existence  of  lymph  follicles  in  the  normal  conjunctiva  is 
disputed,  and  it  is  of  course  possible  that,  in  cases  in  which  they 
are  found,  their  presence  may  be  explained  by  the  repeated  but 
transient  irritation,  to  which  the  conjunctiva,  from  its  exposed 
position,  is  constantly  liable. 

Considerable  difference  of  opinion  prevails  as  to  the  relation 
of  this  disease  to  trachoma,  some  believing  that  it  is  merely  a  mild 


CHAr.  m.]  THE    CONJUNCTIVA.  S3 

or  aborted  form  of  the  latter.  The  question  cannot  be  definitely 
settled  until  the  real  nature  and  cause  of  these  two  affections  are 
known.  Clinically  they  seem  to  be  distinct,  and  from  our  obser- 
vation in  this  country,  where  both  are  common,  there  are  no  practical 
reasons  for  regarding  them  as  different  forms  merely  of  the  same 
disease.  The  chief  points  of  difference  between  them  are  : — Folli- 
cular conjunctivitis  affects  children,  even  in  the  upper-class  schools  ; 
trachoma  occurs  at  all  ages,  but  mostly  in  adults,  and  is  confined 
to  the  lower  classes.  In  follicular  conjunctivitis  the  follicles  are, 
with  rare  exceptions,  confined  to  the  lower  lid  ;  they  are  more 
uniform  in  size  and  more  regular  in  their  arrangement  than  in 
trachoma  ;  furthermore  they  never  produce  cicatrices,  pannus, 
or  any  of  the  ill  effects  which  follow  trachoma. 

The  Symptoms  are  much  the  same  as  those  of  catarrhal  con- 
junctivitis. Frequently  there  is  little  or  no  injection  of  the  bul- 
bar conjunctiva,  and  the  chief  symptom  is  asthenopia — an  inability 
to  continue  near  work  for  any  length  of  time — and  much  distress 
in  artificial  light. 

Causes. — These  are  much  the  same  as  in  simple  catarrhal  con- 
junctivitis. The  long-continued  use  either  of  atropine  or  of  eserine 
is  liable  to  bring  on  the  disease. 

Treatment. — The  most  useful  remedy  in  this  troublesome  affec- 
tion is  an  ointment  of  sulphate  or  citrate  of  copper  of  from  gr.  ss. 
to  gr.  ij  in  3j  of  vaseline.  The  weaker  ointments  should  be  used  at 
first,  and  later  on  the  stronger  ones  if  it  be  found  that  they  cause 
no  excessive  irritation.  The  size  of  half  a  pea  of  the  ointment  is 
inserted  into  the  conjunctival  sac  with  a  glass  rod  once  a  day.  Eye- 
drops of  equal  parts  of  tincture  of  opium  and  distilled  water  are 
of  use  in  some  cases.  Abundance  of  fresh  air,  with  change  from  a 
damp  climate  or  neighbourhood  to  a  dry  one,  is  of  importance. 
If  the  use  of  a  solution  of  atropine  have  induced  the  disease,  it 
should  be  discontinued  ;  and  if  a  mydriatic  be  still  required,  a 
solution  of  extract  of  belladonna  (gr.  viij  ad  gj)  may  be  employed 
in  its  stead. 

In  cases  of  folliculosis  no  local  treatment  is  required.  It  may 
be  well  to  add  that  no  alarm  need  be  created  in  a  school  on  account 
of  the  occurrence  of  follicular  conjunctivitis.  The  utmost  that  may 
be  necessary  is  the  separation  of  those  cases  in  which  there  is  much 
discharge,  which  might  spread  the  catarrhal  inflammation. 


84  DISEASES    OF    THE    EYE.  [chap.  hi. 


*  Tubercular  Disease  oi  the  Conjunctiva.— This  disease  affects 
only  one  eye  as  a  rule,  and  usually  commences  in  the  palpebral 
conjunctiva  of  the  upper  lid  or  in  the  upper  fornix,  and  very  rarely 
on  the  bulbar  conjunctiva,  in  the  form  of  a  caseating  ulcer,  or  as  an 
inflammatory  new  formation  of  the  granuloma  type.  The  granular 
form  occurs  in  the  shape  of  small  yellow  or  grey  subconjunctival 
nodules,  resembling  miliary  tubercles,  or  may  result  in  the  develop- 
ment of  flattened  outgrowths,  cockscomb-like  excrescences,  or 
even  pedunculated  tumours.  The  margins  of  the  ulcers  are  well 
defined,  and  their  floors  either  of  a  yellowish  lardaceous  appearance, 
or  covered  with  greyish-red  granulations.  The  surrounding  con- 
junctiva is  swollen,  and  if  the  palpebral  conjunctiva  be  much  involved 
the  lid  becomes  enlarged  in  every  dimension,  and  the  ulcerative 
process  may  soon  destroy  part  of  the  lid.  It  is  liable  also  to  extend 
to  the  bulbar  conjunctiva,  and  the  cornea  may  become  covered 
with  pannus  or  affected  with  ulcerative  keratitis.  The  preauricular 
and  submaxillary  glands  are  usually  enlarged.  The  discovery  of 
the  tubercle  bacillus  would  make  the  diagnosis  positive,  but  as  it  not 
infrequently  happens  that  the  bacilli  elude  detection  owing  to  their 
scarcity,  while  excised  portions  of  the  growths  do  not  always  show 
a  typical  tubercular  structure,  one  of  the  various  tuberculine  tests, 
or  inoculation  experiments,  may  be  necessary  in  order  to  remove 
all  doubt.  The  application  of  one  or  more  of  these  methods  of 
diagnosis  will  serve  also  to  distinguish  this  disease  from  secondary 
syphilitic  ulceration  of  the  conjunctiva,  between  which  and  the 
tubercular  ulceration  there  is  sometimes  a  resemblance.  Moreover, 
in  the  syphilitic  ulcer  the  detection  of  the  spirochfcta  pallida,  or  the 
application  of  ^Yassermann's  test,  would  decide  the  diagnosis.  The 
granular  form  of  tuberculosis  may  sometimes  be  suggestive  of 
trachoma,  or  even  of  a  malignant  growth.  Tubercular  conjunctival 
disease  is  usually  unattended  by  pain,  or  there  is  only  a  slight  burning 
sensation  ;  but,  again,  when  the  ulceration  is  extensive,  severe  pain 
may  set  in. 

The  disease  is  very  chronic,  its  progress  sometimes  extending 
over  many  years.  It  is  rarely  met  with  except  in  youth.  Some 
of  those  whose  eyes  are  attacked  are  already  the  subjects  of  tuber- 
culosis in  other  organs,  but  very  many  of  them  are  perfectly  healthy 
in  that  respect.  In  fact,  there  is  reason  to  believe  that  tuber- 
culosis of  the  conjunctiva  is  much  more  often  a  primary  disease, 


CHAP.  III.]  THE    CONJUNCTIVA.  85 

the  result  of  an  ectogenic  infection,  even  in  cases  where  already 
tuberculosis  exists  elsewhere,  than  of  infection  occurring  through 
the  blood.  Tubercle  bacilli  introduced  into  the  normal  conjunctival 
sac  have,  it  is  true,  been  found  to  be  harmless,  for  the  intact  epithe- 
lium offers  an  insuperable  obstacle  to  their  entrance  into  the  tissue. 
But  a  superficial  loss  of  substance  of  the  conjunctiva  is  sufficient 
to  allow  of  its  inoculation  with  the  bacilli,  and  then  the  disease 
becomes  established.  The  frequent  lodgment  of  foreign  bodies 
under  the  upper  lid  explains  why  this  is  the  situation  in  which  the 
disease  most  commonly  begins.  But  although  conjunctival  tuber- 
cular disease  is  not  often  secondary  to  tubercular  disease  in  other 
parts  of  the  system,  yet  it  is  itself  liable  to  be  the  starting-point 
of  general  tuberculosis. 

Treatment. — The  fact  last  mentioned  makes  it  most  important,  in 
cases  of  primary  tubercular  disease  of  the  conjunctiva,  to  thoroughly 
eradicate  the  diseased  focus  so  as  to  avert  infection  of  other  organs, 
and  this  can  often  be  effected.  If  the  ulcers  be  not  already  too 
extensive  they  must  be  curetted,  and  the  actual  cautery  freely 
applied.  They  may  then  be  dusted  with  iodoform  or  lactic  acid  may 
be  applied  pure  or  in  50  per  cent,  solutions.  An  ointment  of  4  per 
cent,  picric  acid  in  vaseline  and  lanolin,  applied  three  times  daily 
to  the  diseased  area,  has  proved  useful  in  some  cases.  Injections  of 
tuberculin  are  also  useful  (see  chap.  vii.). 

Parinaud's  Conjunctivitis. — This  well-defined  form  of  subacute  con- 
junctivitis which  may  occur  at  any  age  was  first  described  by  Parinaud. 
With  very  rare  exceptions  it  attacks  only  one  eye.  The  chief  features 
of  the  disease  are  : — The  appearance  of  granulations  or  vegetations  on 
the  tarsal  conjunctiva  or  fornices,  with  painful  and  considerable  en- 
largement of  the  preauricular  and  neighbouring  glands,  on  the  same 
side  as  the  affected  eye  ;  the  disease  is  ushered  in  with  chills  and  malaise  ; 
there  is  slight  mucous,  or  fibrinous,  secretion  but  no  suppuration. 

The  upper  lid  becomes  swollen  and  perhaps  nodular  to  the  touch, 
and  there  is  sometimes  chemosis  ;  but  the  subjective  eye-symptoms  are 
slight.  The  granulations  are  red  or  yellowish,  and  at  first  semi-trans- 
parent, and  they  vary  in  size,  being  at  times  only  as  large  as  the  head  of 
a  pin,  while  again  they  may  even  form  polypoid  growths.  Small  yellow 
granules  and  superficial  erosions  are  often  present,  generally  in  the  furrows 
between  the  large  granulations.  The  glandular  inflammation  sets  in 
along  with,  or  immediately  after,  the  eye-symptoms,  and  may  end  in 
suppuration.  The  sub-maxillary  and  sometimes  even  the  cervical  glands 
are  affected.  A  complete  cure  results  in  the  course  of  some  months, 
without   any   corneal   complication   or   subsequent   scarring   of   the   con- 


80  DISEASES    OF    THE    EYE.  [chap.  hi. 


junctiva.  The  last  symptoms  to  disappear  are  the  ptosis  and  glandular 
enlargement. 

Cause. — No  case  of  the  transmission  of  the  disease  to  others  has  been 
observed.  The  theory  of  an  animal  origin,  which  was  originally  advanced, 
has  not  been  proved.  The  histological  changes,  according  to  Verhoeff 
and  Derby,  consist  in  areas  of  necrosis  in  the  subconjunctival  tissue  and 
extensive  infiltration  with  lymphocytes,  phagocytes,  and  plasma  cells, 
but  no  suppuration.  The  deeper  layers  are  in  a  state  of  clu-onic 
inflammatory  reaction.  The  etiology  is  still  uncertain ;  in  some  cases 
inoculation  experiments  gave  undoubted  evidence  of  tuberculosis,  while 
in  others  similar  experiments  failed.  Verhoeff  found  a  filamentous  organ- 
ism (?  leptothrix)  in  ten  out  of  twelve  cases.  Some  authors  regard  the 
disease  as  bovine  tuberculosis.  The  only  affections  with  which  this  disease 
is  liable  to  be  confounded  are  trachoma  and  tuberculosis. 

Treatment. — The  disease  tends  to  get  well  without  treatment  in  the 
course  of  a  few  months.  Various  remedies  have  been  tried,  but  simple 
antiseptic  treatment  is  almost  sufficient.  The  duration  of  the  disease 
may  be  shortened  by  excision  of  any  large  granulations,  on  the  applica- 
tion of  the  galvanocautery.  If  the  glands  suppurate,  they  should  be 
opened. 

Ophthalmia  Nodosa. — This  disease  is  caused  by  the  irritation  (chemical 
or  mechanical)  of  the  hairs  of  certain  kinds  of  caterpillars.  The  hairs 
give  rise  to  '  foreign  body  '  granulomata,  which  appear  as  small  nodules 
chiefly  on  the  lower  part  of  the  bulbar  conjunctiva.  Both  clinically  and 
microscopically  the  condition  bears  a  resemblance  to  tuberculosis,  hence 
it  has  also  been  called  pseudo-tubercular  conjunctivitis.  The  presence 
of  the  hairs  makes  the  diagnosis  positive.  In  nearly  all  the  recorded 
cases  there  was  a  history  of  caterpillars  having  accidentally  come  into 
forcible  contact  with  the  eye.  The  nodules  are  small,  semi-translucent, 
and  reddish  or  yellowish  grey  in  colour.  The  disease  is  chronic,  as  the 
elimination  or  absorption  of  the  hairs  takes  some  time,  but  it  terminates 
in  complete  recovery,  unless  the  hairs  have  made  their  way  into  the  iris, 
in  which  case  a  severe  iridocyclitis  may  be  set  up. 

Sporotrichosis,  due  usually  to  the  S.  Beurmanni,  also  produces  an 
irregular  nodular  appearance  of  the  tarsal  conjunctiva  with  superficial 
ulceration  and  little  secretion  or  increased  vascularity.  The  preauricular, 
and  sometimes  even  the  submaxillary  glands  become  enlarged.  Cultures 
or  inoculation  may  be  necessary  to  distinguish  it  from  tuberculosis.  Iodide 
of  potassium  in  10  to  20  grain  doses  is  the  best  treatment. 

*  Lupus  of  the  conjunctiva  usually  occurs  as  an  extension  ol  the 
disease  from  the  surrounding  skin,  or  rarely  from  the  lacrimal  sac. 
It  is  seen  as  a  patch  or  patches  of  ulceration,  covered  with  small 
dark-red  protuberances  or  granulations,  chiefly  on  the  palpebral 
conjunctiva,  which  bleed  easily  on  being  touched. 

Like  lupus  of  the  skin,  these  ulcerations  undergo  spontaneous 
healing  and  cicatrisation  in  one  place  (unlike  tubercular  ulceration 


CHAP.  III.]  THE    CONJUNCTIVA.  87 

ill  that  respect),  while  they  are  still  creeping  over  the  surface  in 
another  direction.  But  it  is  now  known  that  lupus,  wherever  it 
may  occur,  is  a  tubercular  disease,  and  that  the  two  forms  differ 
only  in  their  clinical  aspect. 

Treatment. — Scraping  with  a  sharp  spoon,  and  the  application 
of  the  actual  cautery.     Iodoform.     Tuberculin.     X-rays. 

*  Syphilitic  Disease  of  the  Conjunctiva  occurs  both  as  primary 
and  as  secondary  disease.  It  will  be  treated  of  in  chap,  xviii.,  on 
Diseases  of  the  Eyelids. 

Ulcers  of  the  Conjunctiva. — In  addition  to  tubercular  and 
syphilitic  ulcers,  the  following  conditions  may  lead  to  ulceration 
of  the  conjunctiva  : — Injuries,  foreign  bodies,  the  separation  of 
sloughs  or  membranes,  pemphigus,  epithelioma,  smallpox  ;  phlyc- 
tens  also  appear  as  small  superficial  ulcers  on  the  bulbar  conjunc- 
tiva at  one  stage  of  their  existence. 

*  Spring  Catarrh,  or  Vernal  Conjunctivitis. — In  this  extremely 
chronic  but  rather  rare  disease,  which,  strictly  speaking,  is  not  a 
catarrhal  affection,  the  tarsal  conjunctiva  of  the  upper  lid  is  occupied 
by  hard  flattened  bodies  of  a  pale  pinkish  colour  arranged  close 
together,  and  known  as  tesselated  or  pavement  granulations  (Fig.  43). 
They  are  often  slightly  pedunculated.  The  conjunctiva  assumes  a 
milky- white  opalescence.  The  bulbar  conjunctiva  becomes  injected, 
slightly  oedematous,  and  at  the  limbus  somewhat  elevated  with 
hard,  gelatinous-looking  and  nodular  greyish  swellings  in  which 
minute  pale-yellow  dots  can  often  be  seen  (Fig.  44).  The  lower 
palpebral  conjunctiva  is  often  milky-looking,  but  never  shows  granu- 
lations. All  these  appearances  may  be  present  in  the  same  case, 
or  any  one  (the  bulbar  appearances,  or  the  pavement  granulations, 
or  the  milky- white  opacity)  or  two  of  them  may  be  absent.  The 
margin  of  the  cornea  itself  is  apt  to  be  invaded  with  a  more  or  less 
circular  infiltration  resembling  arcus  senilis.  Very  occasionally  the 
cornea  becomes  seriously  implicated  owing  to  the  growth  on  the 
limbus  extending  over  a  great  portion,  or  even  over  the  entire 
cornea.  There  is  a  scanty  mucous  or  muco-purulent  secretion,  and 
the  patient  may  complain  of  the  eyelids  being  stuck  together  in  the 
morning,  of  difficulty  of  using  the  eyes  for  near  work,  of  itching  and 
burning  sensations,  and  all  these  symptoms  are  increased  by  exposure 
to  heat.     The  eyelids  droop  slightly,  giving  the  patient  a  sleepy  look. 

The  condition  of  the  upper  lid  might  at  first  suggest  granular 


88 


DISEASES    OF    THE    EYE. 


[chap.  hi. 


ophthalmia,  from  which  it  differs,  however,  in  the  solidity,  absence 
of  transluceiicy,  and  tesselated  arrangement  of  the  '  granulations,' 

which  moreover  do  not 
attack  the  fornix.  The 
pathological  changes  con- 
sist in  connective  tissue 
proliferation,  hyaline  de- 
generation of  the  subcon- 
junctival tissue,  and 
proliferation  of  the  epi- 
thelium, which  sends  solid 
or  cystic  processes  into 
the  stroma.  It  is  still 
uncertain  which  of  these 
is  the  primary  change. 
The  conjunctival  secre- 
tion is  very  rich  in  eosino- 
phil cells,  a  point  which 
cases. 


Fig.  43. — Spring  catarrh.     Upper  lid 
everted. 
From  sketch  by  L.  W. 


would  assist  the  diagnosis  in  doubtful 

The  affection  is  chiefly  met  with  in  boys  between  six  years  of 
age  and  puberty,  and  is  in  most  cases  bilateral.  The  patients 
sometimes  look  anaemic,  and  have  in  many  cases  enlarged  lymphatic 
glands.  Blood  changes  are  often  present,  and  consist  not  so  much 
in  an  absolute  increase  of  the  white 
corpuscles,  as  in  a  relative  in- 
crease of  lymphocytes. 

The  disease  makes  its  appearance 
rarely  in  conjunction  with  heat  erup- 
tions on  the  skin,  in  warm  weather 
in  the  late  spring  or  early  summer, 
and  generally  disappears,  or  is  much 
modified,  in  the  cool  seasons,  to  re- 
turn again  with  the  next  warm 
season;  and  this  is  liable  to  go  on 
for  many  years.  In  the  intervals 
between  the  attacks  the  congestion 
and  subjective  symptoms  disappear, 
but  the  other  appearances  persist  until  recovery  sets  in 


m 


Fig. 


44. — Circuincorneal  growth 
in  spring  catarrh. 

Sketched  by  L.  W. 


This 


disease  has  been  attributed  to  the  action  of  strong  light, 


CHAr.  iii.l  THE    CONJUNCTIVA.  80 


or  to  ultra-violet  rays,  but  this  is  probably  not  the  case.  Although 
an  occlusive  bandage  often  produces  a  rapid  improvement,  this  is 
not  because  of  the  exclusion  of  light,  but  on  account  of  the  protection 
from  the  air,  for  the  same  result  is  attained  by  the  use  of  well-fitting 
goggles.  We  have  recently  seen  a  remarkably  rapid  improvement 
follow  the  use  of  motor  goggles.  Exposure  to  snow  in  high  altitudes 
where  the  light  is  particularly  strong  is  also  beneficial  owing  to  the 
cool  atmosphere.     The  cause  of  the  disease  is  really  unknown. 

The  Treatment  of  the  majority  of  these  cases  yields  unsatisfactory 
results.  Airtight  goggles  should  be  worn.  So  far  as  possible  all 
exposure  to  the  heat  of  sun  should  be  avoided.  If  possible  the 
patients  should  reside  in  a  cool  place  in  the  summer.  Weak  astrin- 
gent coUyria,  or  ointments,  may  be  used  ;  or  iodoform  ointment 
(1  in  15),  a  little  put  into  the  eye  once  a  day  ;  or  massage  twice  daily 
in  conjunction  with  yellow  oxide  ointment.  Dilute  acetic  acid 
1  or  2  minims  to  the  3J  is  also  recommended.  De  Schweinitz  recom- 
mends borogiyceride  locally,  and  arsenic  internally.  Antipyrin  and 
quinine  internally  have  proved  of  use  in  some  cases.  Strong 
salicylic  acid  ointment  (20  grs. — 5J)  has  been  recommended,  but 
we  have  tried  it  without  much  effect.  Instillations  of  adrenalin 
have  proved  very  beneficial  in  some  cases,  and  good  results  have 
also  been  obtained  with  radium.  It  has  been  stated  by  one 
surgeon  that  removal  of  adenoids  and  enlarged  tonsils  cures  most 
cases. 

Pemphigus  of  the  Conjunctiva. — This  is  another  rare  disease.  It 
has  been  seen  in  connection  with  pemphigus  vulgaris  of  other  parts  of  the 
body,  but  it  also  occurs  as  an  independent  disease.  It  is  attended  by 
attacks  of  much  pain,  photophobia,  and  lacrimation  ;  and  the  conjunctiva, 
at  each  place  where  subconjunctival  exudation  of  serum  has  been  situated, 
undergoes  degeneration  and  cicatricial  contraction.  Such  attacks  succeed 
each  other  at  shorter  or  longer  intervals,  for  weeks,  months,  or  years, 
until  finally,  the  entire  conjunctiva  of  each  eye  may  have  become  de- 
stroyed and  the  eyelids  are  adherent  to  the  eyeball  or  to  each  other.  The 
cornea  gradually  becomes  comjjletely  opaque,  or,  having  ulcerated,  is 
rendered  staphylomatous.  In  the  course  of  the  disease  the  eyelashes 
are  apt  to  become  turned  in  on  the  eyeball,  or  even  entropion  may  follow. 
The  lacrimal  puncta  and  canaliculi  may  become  obliterated  and  the  cilia 
may  disappear  where  the  lids  are  adherent. 

The  foregoing  is  a  description  of  a  severe  case.  In  less  severe  cases 
the  conjunctiva  may  not  be  completely  destroyed,  and  the  cornea  may 
not  be  affected. 

Bullae  are  seldom  seen,  for  the  conjunctival  epithelium  is  so  delicate 


90 


DISEASES    OF    THE    EYE, 


[chap.    III. 


that  the  serous  exudation  beneath  it-  breaks  it  down  at  once.  Conse- 
quently, the  conjunctival  surface  is  found  in  these  cases  to  be  covered  by 
what  looks  like  a  membranous  deposit,  upon  removal  of  which  a  raw 
surface  is  exposed.  These  appearances  have  led  to  the  mistaken 
diagnoses  of  croupous  and  of  diphtheritic  conjunctivitis.  Rarely  deep- 
seated  bluish  cysts  are  present. 
They  existed  in  the  case  illus- 
trated by  Fig.  45. 

Treatment  is  helpless  in  re- 
spect of  arresting  the  progress  of 
the  disease,  or  of  restoring  sight 
when  lost  in  consequence  of  it. 
The  most  that  can  be  done  is  to 
relieve  the  distressing  symptoms 
by  emollients  to  the  conjunctiva, 
^_  _  and,  by  the  use  of  closely  fitting 

j(MX  fe  W^'^'^  ^'^''T^^  goggles,     to     afford    protection 

<c|||i\        c*'         '  from  wind,  dust,  and  sun,     In- 

'  ~^  ternally,    arsenic    is    indicated. 

Operation  may  relieve  the  sym- 
blepharon  and  adherent  eyelids. 
Conjunctivitis  Petrificans.  — 
Under  this  title  Leber  has  de- 
scribed a  rare  and  remarkable 
disease  of  the  conjunctiva.  In 
the  course  of  a  brief  period,  and 
accompanied  by  some  slight  in- 
flammatory reaction,  a  stony 
hard,  white,  chalky  substance  is 
deposited,  in  more  or  less  exten- 
sive patches,  in  the  previously  healthy  conjunctiva,  the  deposit  being 
scarcely  raised  over  the  conjunctival  surface.  The  disease  attacks  a  partof 
the  bulbar  or  palpebral  conjunctiva,  and  may  extend  to  the  intermarginal 
portion  of  the  eyelid.  One  or  both  eyes  may  be  attacked.  After  a  time, 
which  varies  from  a  week  to  several  months,  the  deposit  is  thrown  off  or 
absorbed,  and  the  affected  part  suffers  either  no  detriment  or  there  may 
be  slight  thickening  and  shrinking.  There  is  no  great  tendency  to  corneal 
complications,  but  slight  marginal  ulcerations,  which  heal  readily,  occa- 
sionally occur.  In  one  case  severe  diffuse  opacity  of  the  cornea  seriously 
affected  the  sight.  Frequent  relapses  are  liable  to  take  place  in  the  same 
or  in  different  parts  of  the  conjunctiva,  and  the  whole  course  of  the  affection 
may  extend  over  several  years,  and  then  end  in  complete  cure. 

No  cause  has  as  yet  been  assigned  for  this  disease,  although  Leber 
suspects  it  to  be  an  ectogenic  microbic  infection.  Warm  fomentations, 
and  the  careful  operative  removal  froin  time  to  time  of  the  chalky  scales 
as  they  become  loosened  from  the  main  mass,  have  been  the  chief  features 
of  the  treatment.  Local  instillations  of  diphtheria  antitoxin  were  found 
to  give  relief  to  the  symptoms  in  the  acute  stage,  in  a  case  recently 
recorded  ;  and  in  another,  painting  with  benzoate  of  lithium  solution 
(1  in  40)  proved  very  efficacious. 


Fig.  4i 


CHAP.  III.]  THE    CONJUNCTIVA.  91 

Subconjunctival  Ecchymosis  (Plate  II.  Fig.  6). — The  rupture  of 
a  small  subconjunctival  vessel  in  the  bulbar  conjunctiva,  without 
conjunctivitis,  is  of  frequent  occurrence.  It  suddenly  gives  a  more 
or  less  extensive  purple  hue  to  the  '  white  of  the  eye,'  causing  the 
patient  much  concern.  It  is  common  enough  as  a  spontaneous 
affection  in  old  people,  and  may  be  associated  with  arterio-sclerosis, 
but  it  also  occurs  in  the  young,  and  even  in  children,  from  severe 
straining,  as  in  whooping-cough  and  vomiting.  It  is  occasionally 
significant  of  diabetes.  It  also  occurs  sometimes  during  epileptic 
fits,  and  profuse  subconjunctival  haemorrhage  is  occasionally  found 
in  cases  of  fracture  of  the  base  of  the  skull,  the  blood  having  made 
its  way  along  the  floor  of  the  orbit.  It  is  of  no  importance  so  far 
as  the  integrity  of  the  eye  is  concerned. 

Treatment. — The  extravasated  blood  becomes  absorbed  without 
treatment,  but  massage  through  the  lids  or  dionine  may  accelerate 
the  process. 

Subconjunctival  Serous  Effusion.  Chemosis.— This  has  been 
previously  alluded  to  in  connection  with  some  forms  of  conjunc- 
tivitis, but  it  may  appear  in  inflammatory  affections  of  the  neigh- 
bouring parts  (orbit,  lacrimal  sac,  eyelids).  A  stye  for  instance 
is  sometimes  accompanied  by  well-marked  chemosis.  Dionine 
also  produces  a  serous  exudation,  which  is  preceded,  however,  by 
an  initial  stage  of  congestion.  In  Bright's  disease  a  slight  degree 
of  chemosis  often  occurs.  Tumours  of  the  orbit  may  also  produce 
chemosis  ;  it  is  then  non-inflammatory  and  the  result  of  venous 
stasis.  A  fistula  of  the  anterior  chamber  at  the  limbus  can  also 
give  rise  to  a  limited  chemosis. 

Treatment. — As  a  rule  no  special  treatment  is  required  beyond 
that  of  the  disease  of  which  it  forms  a  symptom  ;  but  if  it  be 
excessive  the  conjunctiva  may  be  snipped  with  scissors,  with  very 
good  effect. 

Emphysema  of  the  Conjunctiva,  when  it  occurs,  is  usually 
associated  with  emphysema  of  the  lids  (see  chap,  xviii.). 

Injuries  of  the  Conjunctiva. — Foreign  bodies  frequently  make 
their  way  into  the  conjunctival  sac,  and  cause  much  pain,  especially 
if  they  get  under  the  upper  lid,  by  reason,  chiefly,  of  their  coming 
in  contact  with  the  corneal  surface  during  motions  of  the  lid  and 
of  the  eye.  If  the  foreign  body  be  under  the  lower  lid  it  will  be 
easily  found  on  drawnig  down  the  latter,  and,  as  it  is  rarely,  if  ever, 


92  DISEASES    OF    THE    EYE.  [ch.aj.  hi. 

embedded  in  the  mucous  membrane  of  the  lower  lid,  it  can  easily 
be  removed  ;  but  if  the  foreign  body  be  under  the  upper  lid  it  is 
necessary  to  evert  the  latter  before  it  is  reached.  Should  the  foreign 
body,  which  usually  lodges  in  the  subtarsal  sulcus,  be  embedded  in 
the  conjunctiva,  it  must  be  pricked  out  with  the  point  of  a  needle 
or  other  suitable  instrument.  For  the  effect  of  minute  foreign 
particles,  e.g.  dust,  etc.,  see  chronic  conjunctivitis  (p.  567). 

Large  foreign  bodies,  such  as  a  grain  of  wheat,  may  lie  hidden 
in  the  upper  fornix  for  several  weeks.  We  have  seen  ulceration 
of  the  cornea  caused  in  this  way,  and  also  cockscomb-like  granu- 
lations in  the  fornix  which  resemble  one  form  of  tuberculosis  of  the 
conjunctiva. 

A  tear  or  wound  of  the  conjunctiva  (usually  of  the  bulbar  portion), 
when  it  occasionally  occurs  without  injury  to  other  parts,  is  in  general 
of  very  slight  moment.  If  the  wound  be  extensive  its  edges  should 
be  drawn  together  with  a  few  points  of  suture  ;  but  otherwise 
healing  will  take  place  with  the  aid  simply  of  a  bandage  to  keep 
the  eye  closed  for  a  few  days. 

A  common  form  of  injury,  which  may  involve  the  conjunctiva 
alone,  is  a  burn  by  acid  or  lime.  In  the  case  of  a  strong  acid  getting 
into  the  eye,  if  the  patient  be  seen  immediately  after  the  occurrence, 
the  whole  conjunctival  sac  should  be  well  washed  out  with  an,  alka- 
line solution  (1  per  cent,  soda  solution).  In  the  case  of  lime,  after 
all  the  larger  particles  have  been  most  carefully  removed  from  the 
eye  with  forceps,  a  weak  solution  of  a  mineral  acid  may  be  used  for 
washing  out  the  conjunctival  sac  ;  or,  as  is  recommended  by  some, 
a  solution  of  sugar  as  thick  as  syrup  may  be  poured  into  the  eye. 
Later,  olive  or  castor  oil,  or  even  butter,  may  be  applied,  the  sub- 
sequent treatment  being  continued  with  weak  sublimate  ointment. 
Cocaine  may  be  employed  to  relieve  the  pain.  But  even  in  the 
case  of  unslaked  lime  the  conjunctiva  may  be  washed  Avith  plain 
water,  provided  plenty  be  used  and  that  the  operation  be  done 
quickly.  The  heat  generated  by  the  slaking  of  the  lime  is  developed 
slowly,  and  further  it  is  the  chemical  action  rather  than  the  heat 
which  is  injurious. 

In  the  case  of  a  severe  burn  of  the  conjunctiva,  the  resulting 
cicatrix  is  liable  to  produce  a  more  or  less  extensive  union  of  the 
eyelid  to  the  eyeball  (Symblepharon),  which  often  interferes  with 
the  motion  of  the  latter,  or  even  with  vision,  if  the  cornea  be  ob- 


CHAP.  III.]  THE    CONJUNCTIVA.  93 

scared.  No  measures  taken  during  the  healing  process  can  prevent 
symblepharon  if  the  degree  of  the  burn  be  such  as  to  bring  it  about. 
The  relief  of  symblepharon  by  operation  will  be  dealt  with  in  chap, 
xviii.  on  Diseases  of  the  Eyelids, 

Injury  of  the  conjunctiva  by  a  chip  l)roken  off  an  anihne  pencil  causes 
a  good  deal  of  irritation,  and  the  conjunctiva  becomes  intenseh' 
stained.  Tannic  Acid  5  to  10  per  cent,  solution  is  recominended  for  the 
treatment.  In  one  such  case  which  we  have  had,  where  the  whole 
bulbar  conjunctiva  was  stained,  washing  out  with  a  weak  solution  of 
alcohol  and  subsequent  treatment  with  glycerine  drops,  both  of  which 
dissolve  aniline  violet,  effected  a  complete  cure  in  the  course  of  a  week, 
and  all  traces  of  the  stain  were  removed. 

Degenerative  Diseases. 

Pinguecula  (pinguis,  fat)  is  the  name  given  to  a  small  yellowish 
elevation  on  the  exposed  part  of  the  bulbar  conjunctiva  near  the 
margin  of  the  cornea,  usually  at  its  inner  side,  more  rarely  at  its 
temporal  margin,  but  sometimes  in  each  place.  It  is  most  commonly 
seen  in  old  people  as  a  rounded  tumour.  Notwithstanding  its  name, 
it  contains  no  fat,  but  is  composed  of  connective  tissue,  hyaline 
deposits,  and  elastic  fibres.  It  is  supposed  to  be  due  to  the  irritation 
caused  by  small  foreign  bodies.  It  rarely  grows  to  a  large  size, 
and  requires  no  treatment  unless  it  become  very  disfiguring,  when 
it  may  be  removed  with  forceps  and  scissors.  When  an  eye  becomes 
congested  or  ecchymosed,  the  pinguecula,  if  present,  stands  out  as 
a  white  or  yellow  patch  and  may  be  mistaken  for  a  phlycten  or 
tumour. 

Epithelial  Plaques  closely  resemble  epithelial  xerosis ;  they  are  slightly 
raised,  flat  triangular  patches  close  to  the  corneal  margin,  white  or 
yellowish  in  colour,  and  are  due  to  alteration  of  the  epithelium,  which 
becomes  ejiidermal  in  character.     These  plaques  are  quite  harmless. 

Pterygium  [jvTepvt,  a  wing).—T\\m  is  a  vascularised  thickening 
of  the  conjunctiva,  triangular  in  shape,  situated  most  usually  to 
the  inside  of  the  cornea,  sometimes  to  its  outer  side,  but  never  above 
or  below  it.  The  upper  and  lower  margins  of  the  triangle  are  limited 
by  a  shallow  depression  or  fold.  The  blunt  apex  of  the  triangle, 
or  head  of  the  pterygium,  lies  on  the  cornea  ;  its  base  is  at  the  semi- 
lunar fold  or  outer  canthus  as  the  case  may  be,  while  the  neck  is 
situated  at  the  limbus.  The  growth  frequently,  but  not  always, 
exhibits  a  tendencv  to  advance  into  the  cornea,  the  centre  of  which 


1)4  DISEASES    OF    THE    EYE.  [chap.   tit. 


it  seldom  reaches,  and  yet  more  rarely  does  it  extend  quite  across 
the  cornea. 

In  its  early  growth  the  pterygium  is  somewhat  thick  and  succu- 
lent looking,  and  very  vascular  ;  but  finally  it  ceases  to  grow,  and 
then  becomes  thin  and  pale,  and  this  is  its  retrogressive  stage  ;  yet 
it  never  entirely  disappears.  Sight  is  not  affected  unless  the  ptery- 
gium extend  over  the  pupillary  region  of  \.h.&  cornea.  A  limitation 
of  the  motion  of  the  eye  to  the  other  side,  and  consequent  diplopia, 
is  sometimes  caused  by  a  pterygium  ;  but,  for  the  most  part,  it 
is  the  disfigurement  alone  which  brings  these  cases  to  the  surgeon. 

Cause. — It  was  formerly  believed  that  the  starting-point  of 
a  pterygium  was  an  ulcer  at  the  margin  of  the  cornea,  which  in 
healing  caught  a  fold  of  the  limbus  conjunctivae  and  drew  it  towards 
the  cicatrix,  throwing  the  mucous  membrane  into  a  triangular 
fold.  But  ulcers  are  never  found  at  the  apex  of  a  true  pterygium, 
and  the  condition  brought  about  in  this  manner  is  known  as  pseudo- 
pterygium  and  differs  in  many  ways  from  true  pterygium.  The 
false  pterygium  may  occur  at  any  part  of  the  circumference  of  the 
cornea.  It  is  very  variable  in  shape,  is  non-progressive,  and  in 
most  cases  a  fine  probe  can  be  passed  under  the  neck  of  the  growth 
where  it  bridges  over  the  limbus.  Again,  in  a  false  pterygium  a 
nebula  or  leucoma  is  frequently  found  at  the  apex. 

Fuchs  believes  that  pterygium  develops  from  a  pinguecula, 
and  that  the  latter  causes  nutritive  changes  in  the  cornea,  loosening 
the  superficial  lamellae,  and  allowing  the  connective  tissue  of  the 
limbus  to  grow  in  on  the  cornea. 

Pterygium  is  not  a  common  affection  in  this  country  ;  it  is 
most  frequently  met  with  in  sandy  or  dry  countries. 

Treatment. — Unless  the  pterygium  be  very  thick,  and  have  in- 
vaded the  cornea  to  some  extent,  or  be  progressing  over  the  cornea, 
it  is  well  to  let  it  alone  ;  the  more  so  as  by  removing  it  the  appear- 
ance given  to  the  eye  is  not  quite  normal,  for  a  mark  is  necessarily 
left  both  on  cornea  and  conjunctiva.  If  it  be  progressive  or  very 
disfiguring,  it  should  be  removed.  This  may  be  effected  either  by 
ligature,  excision,  or  transplantation. 

In  the  method  by  ligature  a  strong  silk  suture  is  passed  through 
two  needles.  The  pterygium  being  raised  with  a  forceps  close  to 
the  cornea,  one  needle  is  passed  under  it  here  and  the  other  needle 
in  the  same  way  close  to  its  base,  the  ligature  being  drawn  half- 


CHAP.  TIT.]  THE    CONJUNCTIVA.  05 

way  through.  The  thread  is  cut  close  behind  each  needle,  thus 
forming  three  ligatures,  which  are  respectively  tied  tight.  In  four 
or  five  days  the  pterygium  comes  away. 

For  excision  the  apex  is  seized  with  a  forceps  and  dissected 
off,  either  with  a  scissors  or  fine  scalpel,  care  being  taken  not  to  injure 
the  true  cornea  ;  or  a  good  plan  is  to  pass  a  strabismus  hook  under 
the  pterygium  when  raised  up  from  the  sclerotic,  and  to  forcibly 
separate  the  corneal  portion  by  drawing  the  hook  under  it.  The 
dissection  is  continued  towards  the  base  of  the  pterygium,  where 
it  is  finished  with  two  convergent  incisions  meeting  at  the  base. 
The  mucous  membrane  in  the  neighbourhood  of  the  base  is  separated 
up  somewhat  from  the  sclerotic,  and  the  margins  of  the  conjunctival 
wound  are  then  brought  together  with  sutures. 

McReynolds's  method  of  transplantation  is  a  good  one.  The  neck 
of  the  pterygium  is  grasped  with  a  forceps  and  transfixed  as  close  as 
possible  to  the  globe  with  a  sharp  cataract,  or  special  knife,  with 
which  every  particle  of  the  growth  should  be  shaved  ofi  the  cornea 
until  only  clear  cornea  is  left.  The  conjunctiva  is  then  divided  along 
the  lower  margin  of  the  pterygium  from  neck  towards  canthus  for  a 
distance  of  J  or  J  an  inch.  The  body  of  the  growth  is  next  separated 
from  the  underlying  sclera,  and  the  conjunctiva  below  the  incision 
loosened  with  scissors  so  as  to  form  a  pocket.  A  black  silk  thread 
armed  with  two  needles  is  passed  through  the  apex  of  the  pterygium , 
the  needles  are  then  carried  under  the  loosened  conjunctiva,  J  of 
an  inch  apart,  and  made  to  emerge  close  to  the  lower  fornix.  The 
edge  of  the  loosened  conjunctiva  is  now"  raised  and  by  gentle 
traction  on  the  sutures  the  pterygium  is  made  to  glide  into  the 
conjunctival  pocket,  and  the  sutures  are  tied.  It  is  important  to 
remove  every  trace  from  the  cornea  and  also  not  to  divide  the  con- 
junctiva above  the  growth;  the  conjunctiva  should  however  be 
undermined  and  freed  from  the  limbus  in  the  neighbourhood  of  the 
neck. 

Pterygia  sometimes  recur  even  after  repeated  operations,  and 
in  rare  instances  a  fleshy  mass  may  be  formed  which  renders  the 
condition  of  the  eye  worse  than  it  had  been  originally.  In  such 
an  event  the  growth  must  be  dissected  up  with  a  surrounding  portion 
of  conjunctiva  and  reflected  towards  the  canthus,  and  on  the  large 
area  of  exposed  sclera,  carefully  cleaned,  a  Thiersch  skin  graft  or 
a  flap  of  mucous  membrane  from  the  lip  should  be  applied  ;    the 


Ofi  DISEASES    OF    THE    EYE.  [ciiAr.  iii. 

flap  margins  may  be  inserted  under  the  edges  of  the  conjunctival 
incision.  It  is  recommended  that  the  graft  should  be  pressed  firmly 
down  on  the  raw  surface  while  the  lids  are  held  open  for  three  to 
five  minutes  before  the  bandage  is  applied. 

*  Lithiasis  consists  in  the  calcification  of  the  secretion  of  the 
Meibomian  glands,  which  are  seen  as  small  white  or  yellowish  spots 
not  larger  than  a  pin's  head  in  the  conjunctiva.  There  may  be  one 
only,  or  very  many.  Concretions  similar  to  these  but  more  super- 
ficial also  occur  in  the  lower  fornix  ;  they  are  found  in  the  interior 
of  newly  formed  glands  which  have  become  cystic.  These  con- 
cretions often  give  rise  to  much  conjunctival  irritation,  and  if  they 
protrude  over  the  surface  of  the  conjunctiva  may  injure  the  cornea. 
Each  one — the  eye  having  been  cocainised — must  be  separately 
removed  by  a  needle,  an  incision  having  first  been  made  with  it  in 
the  conjunctiva  over  the  concretion. 

Uric  acid  deposits  have  been  observed  in  the  palpebral  conjunc- 
tiva in  gouty  patients. 

Xerosis  {tvp^^,  dry),  or  Xerophthalmos,  is  a  dry,  histreless  condition 
of  the  conjunctiva,  associated  in  the  severer  forms  with  slirinking  of  the 
membrane.  There  are  two  forms  of  the  affection — the  parenchymatous, 
which  is  a  local  affection,  and  the  epithelial,  which  is  associated  with 
general  malnutrition. 

In  Parenchymatous  Xerophthalmos  there  is  a  more  or  less  extensive 
cicatricial  degeneration  of  the  conjunctiva,  dependent  upon  changes  in  its 
deeper  layers,  while  its  surface  and  that  of  the  cornea  become  dry,  and  the 
latter  becomes  opaque,  and  the  eye  consequently  sightless.  The  conjunctiva 
shrinks  so  completely,  in  many  of  these  cases,  that  both  lids  are  found 
adherent  in  their  whole  extent  to  the  eyeball,  which  is  exposed  merely 
at  the  palpebral  fissure,  where  the  opaque  and  lustreless  cornea  is  to  be 
seen.  From  what  remains  of  the  conjunctiva,  scales,  composed  of  dry, 
horny  epithelium,  fat,  etc.,  peel  away,  and  the  lacrimal  secretion,  which 
is  much  diminished  in  quantity,  rolls  off  the  oily  surface  of  the  keratinised 
epithelium.  The  motions  of  the  eyeball  are  restricted  in  proportion  to 
the  extent  of  the  conjunctival  degeneration.  There  is  no  cure  for  this 
condition. 

Fig.  45  represents  a  case  of  xerophthalmos,  tlie  result  of  pemphigus, 
which  occurred  in  a  patient  at  the  Royal  Victoria  Eye  and  Ear  Hospital. 
Here  the  eyelids  were  not  wholly  adherent  to  the  eyeball,  and  the  cornea 
remained  clear. 

The  Causes  of  parenchymatous  xerosis  of  the  conjunctiva  are  granular 
ophthalmia,  diphtheritic  ophthalmia,  pemphigus,  burns,  exposure  of  the 
eye  from  exophthalmos,  and  the  condition  is  said  to  be  very  occasion- 
ally seen  as  a  primary  disease,  described  as  essential  shrinking  of  the 
conjunctiva.     ]Many  observers  altogether  deny  the  existence  of  this  primary 


CHAP.  III.]  THE    CONJUNCTIVA.  97 

disease,  and  maintain  that  the  cases  described  as  being  of  that  nature  are 
merely  the  result  of  pemphigus,  and  we  are  inclined  to  agree  with  this 
view. 

Treatinent. — As  cure  is  impossible  in  this  form  of  xerophthalmos, 
the  only  indication  is  to  afford  relief,  so  far  as  it  can  be  done,  from  the 
distressing  sensations  of  dryness  of  the  eyes  which  are  complained  of. 
The  best  applications  are  milk,  glycerine,  olive  oil,  and  weak  alkaline 
solutions,  and  the  eyes  should  be  protected  from  all  irritating  influences 
by  protection  goggles.  Transplantation  of  mucous  membrane,  or  tem- 
porary union  of  the  lids,  produces  as  a  rule  only  a  transient  improvement. 

Epithelial  Xerosis  of  the  conjunctiva  is  confined  to  the  epithelium 
of  that  part  of  the  conjunctiva  which  covers  the  exposed  portion  of  the 
sclerotic  in  the  palpebral  opening.  It  there  becomes  dry  and  dull  and 
covered  with  a  white  foam  due  to  altered  Meibomian  secretion.  The 
xerotic  patches,  which  are  triangular  in  shape,  with  the  base  at  the  corneal 
margin,  are  known  as  Bitot's  Spots.  The  whole  bulbar  conjunctiva  is 
loose,  and  easily  thrown  into  folds  by  motions  of  the  eyeball,  and  there 
may  be  a  good  deal  of  secretion.  This  form  of  xerophthalmos  often 
occurs  in  epidemics,  but  also  sporadically,  accompanied  by  night-blind- 
ness (the  light-sense  unimpaired)  and  contraction  of  the  field  of  vision. 
When  combined  with  night-blindness  the  condition  has  been  noticed 
chiefly  in  persons  of  debilitated  constitution,  who  have  been  exposed  to 
strong  glares  of  light,  and  is  said  to  have  appeared  in  epidemics,  under 
these  conditions,  in  foreign  prisons  and  barracks.  Epidemics  have  been 
chiefly  seen  in  Russia,  especially  during  the  Lenten  fasts.  The  disease 
has  been  found  to  be  associated  with  a  reduction  of  the  haemoglobin  index, 
and  it  has  also  been  attributed  to  deficiency  in  the  fat  content  of  the  blood. 

The  dryness  of  the  conjunctiva  is  due  to  cornification.  of  the  epithelium, 
which  the  tears  cannot  properly  moisten.  Xerosis  bacilli  are  found  in 
large  numbers,  but  are  not  the  cause  of  the  disease. 

Treatment  by  rest,  protection  from  glare  of  light,  nutritious  diet,  and 
tonics,  especially  cod-liver  oil,  invariably  restore  the  eyes  to  their  normal 
functions. 

Again,  epithelial  xerosis  occurs  in  very  young  cachectic  children,  in 
connection  with  a  destructive  ulceration  of  the  cornea  (see  Keratomalacia, 
chap.  v.). 

Hyaline,  Colloid,  and  Amyloid  Degeneration.— This  very  rare  disease 
is  a  primary  affection  of  the  conjunctiva,  and  is  not  associated  with  amyloid 
disease  in  any  other  part  of  the  system.  It  has  been  found  combined 
with  granular  ophthalmia,  but  this  was  most  likely  due  to  a  fortuitous 
coincidence  of  the  two  diseases.  It  is  most  frequently  met  with  in  patients 
between  twenty  and  twenty-five  years  of  age,  generally  in  one  eye  only, 
and  it  is  extremely  chronic,  lasting  for  years.  The  retro-tarsal  folds  and 
palpebral  conjunctiva  are  chiefly  attacked,  but  it  may  also  involve  the 
bulbar  portion.  It  causes  great  tumefaction  of  the  affected  lid,  without 
any  inflammatory  symptoms.  The  eyelid  can  be  but  partially  elevated, 
and  is  often  so  stiff  and  hard  that  it  can  only  be  everted  with  difficulty. 
The  conjunctiva  is  yellowish,  wax-like,  non-vascular,  and  friable.  The 
disease  ultimately  extends  to  the  tarsus, 

7 


98 


DISEASES    OF    THE    EYE. 


[CHAP.    III. 


Microscopically,  homogeneous  masses  ar 


e  fouud  in  tlie   conjunctiva, 


with  variable  staining  properties,  according  to  which  they  are  called 
Amyloid  Hyaline,  or  Colloid.  Calcification  occurs  in  the  later  stages. 
Ra^hhnaiin  believes  that  the  amyloid  changes  are  always  preceded  by 
lymphoid  hifiltration.  Figs.  4G  and  47  are  from  a  case  in  the  Mater  hospital 
which  presented  the  clinical  appearance  of  amyloid  disease  with  the 
histological  structure  of  a  purely  lymphoid  thickening. 

Treatment.— A  partial  removal  of  the  diseased  parts  by  the  knife  or 


Fig.  46. — Lymphoma  of 
conjunctiva. 


FiC4.   47. — Same  case 
as  Fig.  40. 


scraping  is  all  that  is  necessary,  as  the  remainder  disappears  spontane- 
ously, and  further  excessive  scarring  is  thus  avoided.  A  very  good  result 
was  obtained  in  the  above  case  by  this  method. 


Cysts. 

Simple  Cysts  of  the  conjunctiva  are  very  rare.  They  appear  as  clear 
spherical  protuberances  of  about  the  size  of  a  pea,  seated  usually  on 
the  bulbar  conjunctiva.  The  walls  of  the  cysts  contain  but  few  vessels, 
are  thin,  and  almost  transparent ;  while  for  contents  they  have  a  clear 
limpid  fluid.  These  cysts  cannot  as  a  rule  be  moved  from  their  position, 
because  they  are  adherent  to  the  conjunctiva,  which  indeed  takes  part 
in  the  formation  of  their  walls.  The  majority  are  dilated  lymphatic  vessels, 
as  shown  by  their  endothelial  lining.  Small  beadlike  strings  of  dilated 
lymphatics  are  very  frequently  seen  on  the  bulbar  conjunctiva.  Retention 
cysts  are  also  developed  in  Henle's  and  Krause's  glands,  as  well  as  in  the 
so-called  glands  resulting  from  clironic  inflammatory  conditions.  Im- 
plantation cysts,  due  to  proliferation  of  included  surface  epithelium,  occur 
as  the  result  of  injury,  and  congenital  cysts  are  also  met  with. 

Treatment. — The  cyst  may  be  dissected  out,  or  it  may  suffice  to  abscise 
its  anterior  wall,  and  to  scrape  or  cauterise  the  interior. 

Subconjunctival  Cysticercus  is  a  little  more  common  than  simple 
cyst  of  the  conjunctiva.  It  is  distinguished  from  the  latter  by  its  free 
mobility  under  the  conjunctiva,  to  which  it  is  not  attached,  by  its  thicker 
and  more  vascular  walls,  and,  above  all,  by  the  presence  of  a  round, 
white,  opaque  spot  on  the  anterior  surface,  first  pointed  out  by  Sichel, 


CHAP.  III.]  THE    CONJUNCTIVA.  99 


and  looked  on  by  him  as  pathognomonic  of  a  cysticercus.  This  spot 
indicates  the  position  of  the  receptaculum,  and  occasionally,  when  this 
comes  to  be  placed  on  the  posterior  surface  of  the  cyst,  it  may  be  difficult, 
or  impossible,  to  make  the  diagnosis  with  certainty,  but  in  doubtful  cases 
the  character  of  the  booklets  and  the  tuberculated  cyst-wall  will  solve 
the  question  after  the  excision. 

Treatment. — The  cyst  may  be  pushed  to  one  side  under  the  conjunctiva, 
an  incision  made  in  the  latter,  the  cyst  then  pushed  back  again,  and 
dissected  out  through  the  opening. 

Tumours. 

Solid  tumovirs  of  the  conjunctiva  may  be  divided  into  congenital 
(Lipoma,  Nsevus)  and  acquired;  the  latter  are  benign  (Papilloma, 
Angioma,  Lymphoma,  etc.)  or  malignant  (Epithelioma,  Sarcoma). 

Dermo-Lipoma  occurs  as  a  fibro-fatty  congenital  tumour,  usually  situ- 
ated between  the  superior  and  external 
recti  muscles.  They  are  not  encap- 
suled,  and  the  fatty  portion  of  these 
tumours  is  continuous  with  the  orbital 
fat.  Pure  lipoma  is  exceedingly  rare. 
Fig.  48  represents  a  dermo-lipoma  in  an 
unusual  situation.  The  patient  sought 
relief  on  account  of  the  irritation 
caused  by  the  long  hairs  which  were 
only  noticed  about  puberty. 

Osteoma  is   a   very  rare   congenital 
tumour,    which    occurs    in    the    same         ^ig.  48.— Dermo-lipoma  with 
situation  as  the  dermo-lipoma.  nans. 

Naevus  (or  Mole). — This  congenital 
and  usually  pigmented  growth  appears  most  commonly  at  the  limbus,  as 
a  brown  spot,  or  as  a  flat  gelatinous  looking  swelling,  of  a  brown  or 
reddish  colour.  It  may  be  stationary,  or  may  become  progressive  at 
puberty.  The  pigmented  variety  occasionally  forms  the  starting  point  of 
a  pigmented  sarcoma.  Microscopically  a  conjunctival  nsevus  consists  of 
epitheHal  downgrowths  combined  with  groups  or  alveoli  of  smaller  so- 
called  nsevus  cells,  the  origin  of  which  is  doubtful.  Cases  which  have 
been  described  as  benign  epithelioma  and  dermo-epithelioma  were  most 
probably  unpigmented  naevi. 

Treatment. — If  the  naevus  be  disfiguring  or  progressive  it  can  easily 
be  excised. 

Hsemangioma  (Vascular  Nsevus). — This  is  generally  met  with  in  young 
people  and  is  often  congenital,  but  is  sometimes  the  result  of  injury.  It 
may  be  capillary  or  cavernous,  and  is  liable  to  increase  in  size.  It  occurs 
along  with  the  same  conditions  of  the  lids,  but  also  separately,  especially 
on  the  plica   or  caruncle. 

Treatment. — Electrolysis  or  ligature.  Good  results  have  been  obtained 
with  ethylate  of  sodium,  carefully  painted  on,  and  with  carbon  dioxide 
snow» 


100  DISEASES    OF    THE    EYE.  [chap.  hi. 


Polypus  and  Granuloma. — True  mucous  polypi  never  occur  on  the 
conjunctiva.  The  growths,  to  which  the  name  of  polypus  is  given,  are 
tumours  of  different  kinds  which  become  pedunculated  owing  to  the 
movements  of  the  lids  and  eyes  ;  they  are  fibromata  or  papillomata. 
Granulomata,  or  granulation  tissue,  occurring  after  operations  (squint, 
enucleation,  chalazion)  or  f>roduced  by  foreign  bodies,  or  even  by  tuber- 
culosis, may  also  assume  a  polypoid  form.  The  soft  fibromata  are  some- 
times the  cause  of  bloody  tears. 

Lymphoma. — Diffuse  lymphoma  of  the  conjunctiva  occurs  in  leukaemia 
or  pseudo-leuka?mia,  but  also  as  a  primary  affection,  which  is  probably  an 
early  stage  of  amyloid  disease  (see  Figs.  46  and  47).  Small  lymphomatous 
or  lympho-sarcomatous  tumoiu-s  are  met  with  rarely,  chiefly  at  the  inner 
canthus.  Some  of  the  cases  described  as  lymphoma  were  examples  of 
Parinaud's  disease. 

Papilloma,  or  Papillary  Fibroma. — This  is  a  non-malignant  growth, 
which  may  spring  from  any  part  of  the  conjunctival  sac.  It  may  occur 
at  any  age,  and  several  tumours  may  be  present.  It  is  much  more  common 
in  men  than  in  women.  It  appears  in  the  beginning  as  a  small  round 
red  knob.     The   papillomata   growing  from   the   tarsal  conjunctiva   and 

from  the  semi-lunar  fold  frequently 
take  on  a  cauliflower  appearance ; 
while  on  the  bulbar  conjunctiva  and 
in  the  fornix  the  growths  are  liable 
to  be  pedunculated,  with  a  papillary 
surface.  The  limbus  of  the  con- 
junctiva is  a  favourite  seat  for  a  papil- 
loma (Fig.  49),  and  in  the  early  stage 
it  may  be  impossible  to  disting\iish  it 
from  an  epithelioma.  But  at  a  later 
stage,  when  the  growth  has  overlapped 
the  cornea,  the  papilloma  merely 
Fig.  49. — Papilloma  growing  at  overlies  it  and  can  be  lifted  freely  off  it 
the  limbus.  with  a  probe,  while  the  epithelioma. 

Sketched  by  L.  W.  as  a  rule,  infiltrates  the  corneal  tissue. 

Moreover,  enlargement  of  the  pre- 
auricular gland  only  occurs  in  the  latter.  But  it  must  be  remembered 
that  papillomata  in  elderly  people  sometimes  become  malignant. 

Treatment. — Thorough  removal  with  knife  or  scissors,  followed  by  the 
actual  cautery,  as  otherwise  the  growth  is  liable  to  recur. 

Malignant  Tumours  (Epithelioma,  Sarcoma). — These  rare  growths 
generally  take  their  origin  in  the  limbus,  most  frequently  at  the  temporal 
side.  They  are  often  extremely  slow  in  their  growth,  lasting  perhaps 
several  years  before  attaining  any  considerable  size.'  They  are  epibulbar 
tumours,  that  is  to  say,  they  spread  on  the  surface  of  the  eyeball  and  very 
rarely  penetrate  it.  They  may  be  pigmented  or  not.  The  pigmentation 
is  explained  by  the  fact  that  the  limbus  contains  pigment,  although  gener- 
ally so  slight  in  amount  as  not  to  be  visible  to  the  naked  eye.  There  is 
no  cachexia,  and  the  liability  to  metastases  is  less  than  in  the  case  of 
intra-ocular  growths,  but  the  tendency  to  local  recurrences  is  very  great. 


CHAP.  III.]  THE    CONJUNCTIVA.  101 


The  disease  is  rarely  met  with  under  forty  years  of  age.  On  account  of 
the  alveolar  structure  so  often  present  in  these  tumours,  differences  of 
opinion  not  infrequently  arise  in  the  effort  to  distinguish  between  sarcoma 
and  epithelioma.  The  tumour  soon  becomes  surrounded  by  a  localised 
congestion,  and,  as  it  grows,  it  interferes  with  sight  and  prevents  closure 
of  the  lids,  but  does  not  cause  much  pain  until  the  late  stages,  when  ulcera- 
tion and  hcemorrhage  are  apt  to  occur. 

Ej)itheliomata  are  usually  non-pigmented,  and  at  first  may  be  mistaken 
for  phlyctens — of  which,  however,  the  margins  are  not  so  steep — or  for 
papillomata  {vide  supra).  The  surface  is  wart-like  or  papillary,  or  it  may 
be  nodular,  but  the  nodules  are  not  so  smooth  nor  so  large  as  in  a  sarcoma. 
The  cornea  becomes  infiltrated  by  the  growth  and  the  lymphatic  glands 
may  bo  enlarged. 

Sarcomata  on  the  other  hand  are  generally  pigmented,  the  tumour  is 
smooth  or  nodular,  and  rarely  polypoid,  and  when  it  extends  over  the 
cornea,  is  not  adherent  to  it,  or  at  least  does  not  involve  it  except  in  a  very 
late  period. 

But  conjunctival  sarcoma  also  starts  from  other  parts  of  the  conjunctiva, 
and  in  a  case  at  the  Royal  Victoria  Eye  and  Ear  Hospital  sarcomatous 
tumours  were  four  times  removed  from  different  parts  of  the  fornix,  an 
interval  of  some  months  elapsing  between  the  appearance  of  each  small 
tumour,  and  finally  enucleation  became  necessary.  Malignant  growths 
on  the  eyelids  often  involve  the  conjunctiva  secondarily,  and  this  is  a 
common  occurrence  in  rodent  ulcer. 

Treatment, — Both  epithelioma  and  sarcoma  of  the  conjunctiva  demand 
prompt  operative  removal,  in  order  to  prevent  an  extension  of  the  growth 
to  the  rest  of  the  eye,  as  well  as  to  avert  metastases  to  other  organs.  The 
knife  and  actual  cautery  may  save  the  eye  and  the  patient's  life  in  the 
early  stages.  When  a  recurrence  takes  place  it  is  safer  to  remove  the 
eye,  more  especially  if  the  patient  cannot  be  kept  under  constant  super- 
vision. 

Tumours  of  the  Caruncle. — A  great  variety  of  tumours,  benign  or 
malignant,  may  grow  from  the  caruncle.  They  may  arise  from  the 
epithelium,  or  conjunctival  stroma,  and  may  be  dermoid,  lymphomatous, 
or  sarcomatous. 


CHAPTER    IV. 

PHLYCTENULAR    CONJUNCTIVITIS,   AND   KERATITIS. 

Both  from  a  clinical  and  nosological  point  of  view  it  would  be 
incorrect  to  divide  this  affection  into  two,  under  the  heads  of  Diseases 
of  the  Conjunctiva  and  Diseases  of  the  Cornea  ;  therefore  it  is 
treated  of  here  as  one  disease,  and  on  account  of  its  importance  a 
special  chapter  is  given  to  it.  It  is  important,  because  it  is  ex- 
cessively common,  and  because  it  is  capable  of  causing  considerable 
damage  to  sight.  Moreover,  even  when  it  occurs  on  the  cornea,  it 
might,  strictly  speaking,  be  regarded  as  a  conjunctival  disease, 
for  the  layer  of  the  cornea,  which  it  primarily  attacks,  is  the  epithe- 
lium, and  this — and  probably  also  Bowman's  membrane  and  the 
anterior  layers  of  the  true  cornea — as  we  know  from  the  foetal  develop- 
ment of  the  membrane,  is  a  continuation  of  the  conjunctiva  in  a 
modified  form  over  the  cornea. 

The  disease  is  characterised  by  the  eruption  of  phlyctens  {(jiXvKTaiva, 
a  vesicle,  or  pustule)  on  the  conjunctiva  bulbi,  on  the  conjunctival 
limbus,  or  on  the  cornea.  It  is  chiefly  a  disease  of  children  up  to 
the  eighth  or  tenth  year  of  age.  It  is  seen  occasionally  in  adults, 
especially  in  women.  The  appearance  of  the  phlycten  is  preceded 
by  a  localised  patch  of  ciliary  congestion,  which  remains  for  some 
time  after  the  phlycten  has  healed  (Plate  II.,  Fig.  3). 

Notwithstanding  the  derivation  of  the  word,  a  phlycten  is 
originally  neither  a  vesicle  nor  a  pustule.  It  is  a  formation  sui 
generis,  and,  when  on  the  conjunctiva,  is  a  solid  elevation  consisting 
of  leucocytes,  and  some  lymphocytes,  also  giant  cells  and  epithelioid 
cells,  and  is  of  a  greyish  colour.  In  a  late  stage  the  phlycten,  especi- 
ally on  the  cornea,  may  become  a  pustule  by  infection.  On  the  con- 
junctiva two  types  of  the  disease  can  be  recognised  : — 

1.  The  Solitary,  or  Simple,  Phlycten.— Of  this  there  may  be 
one  or  several,  varying  in  size  from  1  mm.  to  4  mm.  in  diameter. 

102 


CHAP.  IV.]         PHLYCTENULAR    CONJUNCTIVITIS.  103 

The  vascular  injection  is  immediately  around  the  phlycten,  and  is 
not  diffused  over  the  conjunctiva,  yet  it  is  true  that  occasionally 
any  form  of  phlyctenular  disease  may  be  associated  with  simple 
conjunctivitis,  which  is  to  be  regarded  as  secondary  to  the  phlyc- 
tenular affection.  At  first  there  may  be  shooting  pains  and  lacri- 
mation,  but  these  soon  pass  away.  If  the  phlyctens  be  not  seated 
close  to  the  cornea  the  affection  is  not  serious  ;  and  the  length  of 
time  required  for  its  cure  depends  on  the  size  of  the  phlyctens, 
varying  from  seven  to  fourteen  days,  as  a  rule. 

2.  Multiple,  or  Miliary,  Phlyctens.— These  are  very  minute, 
like  grains  of  fine  sand,  and  are  always  situated  on  the  limbus  of 
the  conjunctiva,  which  is  swollen.  The  general  injection  and 
swelling  of  the  conjunctiva  are  considerable,  and  there  may  be  a 
good  deal  of  conjunctival  discharge  ;  and,  occurring  as  it  does  almost 
exclusively  in  young  children,  the  affection  may  be  called  Ecze- 
matous  Conjunctival  Catarrh  of  Children  (Horner).  The  irritation, 
and  so-called  photophobia,  and  lacrimation  are  often  considerable. 
This  form  is  very  apt  to  appear  after  measles  and  scarlatina. 

Both  forms  are  liahle  to  extend  to  the  cornea,  and  then  only  does 
the  disease  become  serious.  This  event  may  come  about  in  the 
following  different  w^ays  : — 

The  Solitary  Phlycten  may  be  seated  partly  on  the  limbus  con- 
junctivae and  partly  on  the  margin  of  the  cornea,  and  may  undergo 
resolution. 

Or,  it  may  give  rise  to  a  deep  ulcer,  which  either  heals,  leaving 
a  scar,  or  perforates,  causing  prolapse  of  the  iris,  etc. 

Or,  it  may  form  the  starting-point  of  a  fascicular  keratitis,  the 
pustule  becoming  an  ulcer,  at  the  margin  of  which  the  corneal 
epithelium  is  raised  and  infiltrated  in  crescentic  shape.  This  now 
steadily  advances  for  many  weeks  towards  the  centre  of  the  cornea, 
followed  by  a  leash  of  vessels  which  has  its  termination  in  the 
concavity  of  the  crescent.  The  process  is  accompanied  by  much 
irritation  of  the  terminal  branches  of  the  fifth  nerve  in  the 
cornea,  and  the  consequent  reflex  blepharospasm.  A  permanent 
mark  indicates  the  track  of  the  ulcer. 

The  Multiple  Miliary  Phlyctens  on  the  limbus  conjunctivae  may 
cause  some  slight  superficial  infiltration  and  vascularisation  of 
the  cornea  in  their  immediate  neighbourhood,  which  pass  off  when 
the  phlyctens  disappear. 


1U4  DISEASES   OF    THE   EYE.  [chap.  iv. 

Or,  they  may  be  accompanied  by  deeper  marginal  infiltrations 
of  the  cornea,  which  become  confluent  and  result  in  an  ulcer  that 
extends  along  the  margin  of  the  cornea  for  some  distance,  forming 
a  ring  ulcer.  It  is  a  serious  form  of  ulcer  ;  for,  if  it  extend  far  around 
the  cornea,  it  may  destroy  the  latter  in  a  few  days  by  cutting  off 
its  nutrition. 

The  only  condition  which  may  give  rise  to  an  error  in  diagnosis  is  a 
patch  of  sclerilis  (chap.  vi.).  In  scleritis  the  vascular  injection  is  deeper 
than  the  conjunctival  vessels,  and  of  a  more  purple  colour  (Plate  II., 
Fig.  5)  ;  the  affected  part  is  usually  tender  on  pressure,  and  there  is 
no  vesicular  or  pustular  formation  on  it. 

Primary  Phlyctenular  Keratitis  occurs  principally  in  three 
different  forms  :^(1)  Very  small  grey  sub-epithelial  infiltrations, 
which  are  apt  to  result  in  small  ulcers,  and  then  heal,  leaving  a  slight 
opacity.  This  opacity  may  ultimately  quite  disappear,  especially 
in  the  case  of  children,  and  when  situated  peripherally.  (2)  Some- 
what larger  and  deeper  infiltrations,  resulting  in  ulcers  of  correspond- 
ing size,  which  heal  by  aid  of  vascularisation  from  the  margin  of 
the  cornea.  The  opacity  left  after  these  ulcers  is  rather  intense, 
and  clears  up  but  little,  especially  if  the  situation  be  central.  (3) 
Large  and  deep-seated  pustules,  due  to  secondary  infection,  often 
at  the  centre  of  the  cornea,  giving  rise  to  large  and  deep  ulcers, 
which  may  be  accompanied  by  hypopyon  and  even  by  iritis,  and 
which  frequently  go  on  to  perforation. 

Photophobia  is  usually  a  prominent  symptom  in  phlyctenular 
keratitis,  and  the  blepharospasm  often  causes  eczematous  fissures 
at  the  outer  canthus.  The  term  photophobia,  however,  is  not 
altogether  correct,  for  it  is  the  fifth  nerve  (from  the  cornea) 
which  is  mainly  the  afferent  nerve  here,  rather  than  the  optic 
nerve.  This  is  evident  from  the  fact  that  in  the  dark  the  patient 
does  not  get  complete  relief.  The  explanation  of  this  reflex 
blepharospasm  has  been  given  by  Iwanoff,  who  showed  that  the 
cells  which  go  to  form  the  phlycten  follow  the  course  of  the  nerve 
filaments,  which  they  must  irritate  in  their  progress.  (Figs.  50  and 
51  are  after  Iwanoff.) 

Enlarged  cervical  glands,  eczema  of  the  eyelids,  face,  and 
external  ear,  and  rhinitis,  frequently  accompany  phlyctenular 
conjunctivitis  and  keratitis. 

In  these  cases,  in  children  of  three  or  four  years  of  age,  temporary 


PHL  YGTEN  ULAR    CON  J  UNCTI VITIS. 


105 


Fig.  50. — E,  Epithelium  ;  B,  Ant,  elastic 
Lamina  ;  C,  True  Cornea  ;  N,  Nerve  Fila- 
ment, with  Lymph  Cells  on  its  course  ;  D, 
Phlyctenula. 


amaurosis  has  sometimes  been  observed  after  a  severe  and  long- 
continued  blepharospasm  has  passed  away.     The  patient  is  found 

to  be  unable  to  see  even 
large  objects,  or  to  find 
his  way,  although  the 
pupil-reflex  is  active, 
and  a  strong  light  may 
still  be  distressing. 
There  are  no  ophthal- 
moscopic appearances. 
This  blindness  passes 
away  completely, 
usually  in  from  two  to 
four  weeks,  although 
the  interval  before  re- 
covery of  sight  may  be 
several  months.  A  certain  mental  dullness,  which  also  ultimately 
disappears,  is  noticed  in  some  cases.  This  temporary  loss  of  sight 
has  been  held  by  some  to  be  due  to  disturbance  of  the  intra-ocular 
circulation,  and  of  the  nutrition  of  the  retina  from  pressure  of  the 
eyelids  on  the  eyeball.  It  has  been  regarded  by  others  as  having  a 
cerebral  origin  of  a  functional  nature  ;  for  it  is  likely  at  this  tender 
age,  when  the  psychophysical  processes  are  not  as  yet  firmly  estab- 
lished, that  the  desire  not  to  see,  and  the  active  withdrawal  from 
the  act  of  vision,  may  lead  in  a  short  time  to  a  functional  paralysis 
of  the  visual  centres  in  the  brain  ;  and  these  centres  may  take 
some  time  to  recover,  or  to 
re-learn,  their  functions, 
when  the  ground  for  the  sus- 
pension of  the  latter  has 
ceased. 

As  a  result  of  frequent  re- 
lapses of  phlyctenular  kera- 
titis, a  superficial  pannus-like 
vascularisation   may  form  in 

the  cornea,  in  those  parts  of  it  which  have  been  chiefly  attacked. 
In  many  cases  the  cornea  presents  the  appearance  of  ill-defined 
irregular  opacities,  due  to  the  combination  of  fresh  phlyctens 
with  the  nebula  left  by  previous  attacks  of  the  disease. 


Fig.  51. 


lOG  DISEASED    OF    THE   EYE.  [chap.  iv. 

An  indolent  form  of  ulcer  is  sometimes  met  with,  known  as 
Absorption  ulcer  (Facetted  Ulcer).  It  is  accompanied  by  but  little 
opacity  and  by  no  vascularisation,  and  is  usually  seated  at  or  near 
the  centre  of  the  cornea,  where  it  presents  the  appearance  of  a  shallow 
pit.  The  healing  process  may  take  months  to  be  completed,  and 
slight  opacity  remains.  Often  the  defect  is  never  quite  filled  up, 
but  a  small  facet  is  left,  which  is  liable  to  interfere  with  vision. 

The  absorption  ulcer  does  not  tend  to  perforate,  nor  to  spread 
over  the  surface  of  the  cornea. 

Cause. — As  already  stated,  this  is  a  disease  of  childhood, 
although  it  is  extremely  rare  in  the  first  year  of  life.  In  adults  it 
is  uncommon. 

The  strumous  constitution — as  indicated  by  the  swollen  nose 
and  upper  lip,  and  sometimes  by  the  enlarged  lymphatics  in  the 
neck,  and  by  the  eczema — which  is  allied  to,  if  not  indeed  a  form  of, 
tuberculosis,  is  that  most  liable  to  this  affection.  Often,  however, 
it  will  be  found  in  strong  children  with  apparently  perfect  general 
health  ;  but  even  in  them  there  is  probably  some  irregularity  of 
nutrition,  of  which  the  great  tendency  to  recurrence  of  the  eye 
affection  is  evidence. 

The  suspicion  that  phlyctenular  disease  is  often  a  manifestation 
of  tuberculosis  has  been  gaining  ground.  The  evidence  in  favour  of 
this  view  is  : — That  the  instillation  of  tuberculin  into  the  conjunctival 
sac  sometimes  produces  a  crop  of  phlyctens.  That  giant  cells  and 
epithelioid  cells  have  been  found  (Leber)  in  phlyctens.  That  the 
opsonic  index  for  tubercle  has  been  found  (Nias  and  Paton)  to  be 
low  in  cases  of  phlyctenular  disease,  and  that  Von  Pirquet  and  tuber- 
culin tests  are  positive  in  the  vast  majority  of  cases.  On  the  other 
hand  tubercle  bacilli  have  not  been  found  in  phlyctens  and  inocula- 
tion experiments  have  not  produced  tuberculosis  in  animals.  It  is 
now  believed  that  the  disease  is  caused  by  the  toxins  of  tubercle 
bacilli,  and  that  irritants  of  different  kinds,  staphylococci  for  instance, 
acting  in  tuberculous  patients  may  induce  it.  Tubercular  disease 
in  other  parts  of  the  body  cannot  always  be  detected  in  these  patients, 
but  tubercular  cervical  glands  and  tubercular  disease  of  the  bones 
are  present  in  a  fair  proportion  of  the  cases. 

Treatment. — The  solitary  phlycten  of  the  conjunctiva  is  best 
treated  with  a  2  per  cent,  yellow  oxide  of  mercury  ointment,  of 
which  a  portion  of  the  size  of  a  hemp-seed  should  be  put  into  the 


CHAP.  IV.]  PHLYCTENULAR    CONJUNCTIVITIS.  107 

eye  with  a  small  glass  rod,  once  a  day.  To  obtain  the  best  result 
with  this  ointment,  its  base  should  consist  of  10  parts  of  pure  white 
vaseline,  and  one  part  each  of  anhydrous  lanoline  and  water.  The 
yellow  oxide  is  to  be  freshly  precipitated  and  in  very  fine  powder, 
and  when  it  has  been  well  rubbed  up  with  the  water,  the  anhydrous 
lanoline  and  vaseline  are  added.  This  ointment  contains  no  fatty  sub- 
stance, and  consequently  mixes  with  the  tears  and  comes  thoroughly 
in  contact  with  the  surface  of  the  eye.  Ordinary  lanoline  contains 
olive  oil.  The  ointment  should  not  be  unnecessarily  exposed  to  light 
or  air.  A  little  pure  calomel  insufflated  into  the  eye  once  a  day  will 
also  cure  ;  but  this  remedy  should  not  be  employed  if  iodide  of 
potassium  is  being  taken  internally,  for  then  iodide  of  mercury  is 
liable  to  be  formed  in  the  conjunctiva. 

Miliary  phlyctenular  conjunctivitis,  when  accompanied  with  a 
muco-purulent  discharge,  may  be  treated  by  the  application  of  Sol. 
argent,  nitr.  (gr.  v  ad  §j)  to  the  everted  conjunctiva,  or  one  of 
the  organic  silver  salts  may  be  used  instead;  if  the  phlyctenular 
appearance  predominate  over  the  catarrhal,  the  yellow  oxide  of 
mercury  ointment  or  insufflations  of  calomel  may  be  preferred. 
Indeed,  practically,  the  two  latter  remedies  are  applicable  in  all 
these  cases. 

When  the  cornea  is  slightly  affected  near  the  margin,  warm 
fomentations  should  be  used  in  addition. 

Where  a  large  pustule  on  the  margin  of  the  cornea  has  resulted 
in  a  deep  ulcer,  with  tendency  to  perforate,  and  is  accompanied  by 
much  pain,  paracentesis  of  the  anterior  chamber  through  the  floor 
of  the  ulcer,  the  pupil  having  first  been  brought  well  under  the 
influence  of  eserine  to  prevent  prolapse  of  the  iris,  cannot  be  too 
strongly  advocated.  The  good  effect  of  this  will  be  very  soon 
apparent :  the  pain  disappears,  the  patient  sleeps,  the  ulcer  becomes 
vascularised,  and  healing  sets  in.  Cauterisation  of  the  ulcer  in 
an  early  stage  with  the  galvano-cautery  is  also  good  practice  ; 
but  in  these  cases  paracentesis  is  preferable.  Many  surgeons 
trust  too  much  to  eserine,  warm  fomentations,  and  a  pressure 
bandage. 

For  the  fascicular  keratitis  the  yellow  oxide  of  mercury  oint- 
ment is  again  in  its  place.  When  the  crescentic  infiltration  is  very 
intense  it  is  well  to  touch  it  with  the  galvano-cautery. 

For  the  ring  ulcer  a  pressure  bandage,  under  which  an  anti- 


108  DISEASES   OF   THE   EYE.  [chap.  iv. 

septic  dressing  (boric  or  salicylic  acid,  or  perchloride  of  mercury) 
has  been  placed,  is,  perhaps,  the  best  method  of  treatment.  Warm 
fomentations  promote  vascular  reaction,  and  may  be  used  with 
benefit  at  each  change  of  bandage. 

For  primary  phlyctens  of  the  cornea,  in  the  form  of  the  minute 
grey  superficial  infiltration  or  ulcer,  nothing  beyond  atropine,  with 
warm  fomentations  and  a  protective  bandage  to  keep  the  eyelids 
quiet,  should  be  used.  When  reparation  of  the  ulcer  has  com- 
menced, insufflations  of  calomel  or  weak  yellow  oxide  of  mercury 
ointment  may  be  employed. 

For  the  large  infected  phlycten,  resulting  in -a  large  and  deep 
ulcer,  often  situated  at  the  centre  of  the  cornea,  with  hypopyon 
and  iritis,  warm  fomentations  (camomile,  or  poppy-head,  at  90° 
Fahr.,  for  twenty  minutes  three  times  a  day),  atropine,  boric  acid, 
xeroform  or  iodoform  as  ointment  or  powder,  and  a  protection  band- 
age form  the  treatment  in  the  early  stages.  Here,  also,  the  ulcer 
may  be  punctured  with  the  very  best  results  in  respect  of  hastening 
the  cure,  or  the  galvano-cautery  may  be  used  with  advantage.  In 
the  stage  of  reparation  the  yellow  oxide  of  mercury  ointment  or 
insufflations  of  calomel  are  very  useful. 

In  nearly  all  cases  of  phlyctenular  keratitis  dionine  (5  per  cent, 
solution)  aids  the  cure. 

In  all  forms  of  phlyctenular  ophthalmia  those  favourite  remedies, 
blisters,  setons,  and  leeching,  should  be  avoided.  The  first  two 
worry  the  patient,  give  rise  to  eczema  of  the  skin,  and  are  not  to 
be  compared  in  their  power  of  cure  with  the  measures  above  recom- 
mended ;  while  leeching  gives,  at  best,  but  temporary  relief,  and 
deprives  the  patient  of  blood  which  he  much  requires. 

If  the  blepharospasm  be  obstinate  in  spite  of  the  use  of  atropine, 
plunging  the  child's  face  into  a  basin  of  cold  water  is  most  efficacious. 
The  face  is  kept  under  the  water  until  the  patient  struggles  for 
breath,  and  this  immersion  is  repeated  two  or  three  times  in  rapid 
succession,  and  used  every  day  if  necessary.  The  beneficial  effect 
is  often  most  remarkable. 

The  general  treatment,  notwithstanding  the  so-called  photo- 
phobia, should  consist  in  open-air  exercise,  unless,  indeed,  there  be 
an  ulcer  which  threatens  to  perforate.  It  is  not  well  to  keep  the 
eyes  (unless  there  be  a  corneal  ulcer),  or  patient's  face,  covered  with 
bandages  or  shades,  nor  to  confine  him  to  a  dark  room.     A  pair  of 


CHAP.  IV.]         PHLYCTENULAR   CONJUNCTIVITIS.  100 


smoked  glasses  are  the  best  protection  from  strong  glare  of  light ; 
and  shady  places  can  be  selected  when  the  patient  is  out  of  doors. 
Cold  or  sea  baths,  followed  by  brisk  dry  rubbing.  Easily  assimilated 
food  at  regular  meal  hours,  but  no  feeding  between  meals.  Regula- 
tion of  the  bowels.  Internally  :  cod-liver  oil,  maltine,  iron,  arsenic, 
syrup  of  the  phosphate  of  lime,  and  such-like  remedies  are  indicated. 

The  great  tendency  to  recurrence  is  one  of  the  most  trouble- 
some peculiarities  of  all  kinds  of  phlyctenular  ophthalmia  ;  and 
in  order  to  prevent  this,  so  far  as  possible,  it  is  important,  not  only 
to  improve  the  general  health,  but  also  to  continue  local  treatment 
until  the  eye  is  perfectly  white  on  the  child's  awaking  in  the  morning, 
and  even  for  fourteen  days  longer.  This  prolongation  of  the  treat- 
ment will  also  assist  in  clearing  up  opacities,  as  best  they  may  be. 
For  this  after-course  of  treatment  calomel  insufflations  may  be  used. 
In  cases  which  do  not  readily  yield  to  ordinary  treatment  tuberculin 
or  a  staphylococcic  vaccine  should  be  tried. 

Nothing  can  be  done  for  the  opaque  scars  left  on  the  cornea 
by  ulcers  when  all  inflammatory  symptoms  have  subsided.  If 
the  ulcer  have  been  very  superficial  the  resulting  scar  in  young 
children  may  disappear  in  course  of  time.  Deep  ulcers  cause  more 
opaque  and  permanent  scars,  and  ulcers  which  have  perforated 
produce  the  greatest  opacity.  Some  of  the  very  disfiguring  scars 
may  be  tattooed  (chap.  v.). 

The  degree  of  the  defect  of  vision  to  which  an  opacity  of  the 
cornea  may  give  rise  depends,  in  the  first  instance,  on  the  position 
of  the  opacity.  If  it  be  peripheral,  the  vision  may  be  perfect ;  but 
if  it  be  in  the  centre  of  the  cornea,  sight  may  be  seriously  damaged. 
Even  a  slight  nebula,  barely  visible  to  the  observer,  will  cause  serious 
disturbance  of  vision  if  situated  in  the  centre  of  the  cornea  ;  while 
in  the  same  situation  the  very  opaque  scar  of  a  deep  ulcer  will  pro- 
duce a  proportionately  greater  defect.  If  a  central,  but  not  deep, 
ulcer  should  not  become  completely  filled  up  in  healing,  and  a  facet 
remain,  vision  will  also  suffer  much  in  consequence  of  irregular 
refraction  of  the  light  which  passes  through  the  facet,  even  though 
there  may  be  but  little  opacity. 


CHAPTER    V. 

DISEASES   OF  THE    CORNEA. 

The  cornea  is  a  clear  membrane  having  a  regular  curvature  and  a 
smooth  surface  which  reflects  objects  without  distortion,  as  long  as 
the  epithelium  and  curvature  are  normal.  It  is  non-vascular  and 
derives  its  nourishment  by  transudation  from  the  vascular  loops  at 
the  limbus.  Owing  to  its  being  overlapped  by  the  conjunctiva  to  a 
greater  degree  above  and  below  than  at  the  sides,  it  is  usually  oval 
horizontally;  measuring  about  11  "5  mm.  by  10"5  mm.  Its  thick- 
ness at  the  circumference  is  only  1  mm.  and  less  than  that  in  the 
centre.  For  clinical  purposes  it  may  be  considered  as  consisting  of 
three  layers — the  surface  epithelium,  the  proper  substance  of  the 
cornea,  and  Descemet's  membrane,  lining  the  posterior  surface. 
In  examining  the  cornea  the  following  points  may  require  to  be  noted  : 
the  size,  shape  (outline),  degree  of  transparency,  condition  of 
surface  and  sensibility. 

Clinical  Methods  of  Examining  the  Cornea. 

1.  By  Diffuse  Daylight.  The  patient  is  placed  with  his  face 
towards  the  window,  and  the  cornea  is  carefully  inspected  while 
he  keeps  both  eyes  open.  His  upper  lid  is  then  gently  raised  with 
the  surgeon's  thumb,  and  he  is  called  on  to  direct  his  eyes  upwards, 
downwards,  to  the  right,  and  to  the  left,  so  that  every  part  of  the 
affected  cornea  may  be  seen  under  the  most  favourable  and  varied 
incidence  of  the  light.  Should  there  be  much  reflex  blepharospasm, 
the  instillation  of  cocaine  may  be  necessary.  With  small  children 
it  is  often  necessary  to  adopt  the  plan  illustrated  by  Figs.  34  and  35. 

2,  By  Focal,  or  Oblique,  Illumination.  In  the  dark  room  the 
light  of  the  ophthalmoscope  lamp  is  focussed  with  a  +  14'0  D  lens 
on  the  cornea,  which  is  thus  seen  brilliantly  lighted  up.  The  lamp 
must  be  placed  in  front  of,  and  slightly  to  the  left-hand  side,  of  the 
patient,  and  about  two  feet  from  his  eye.     The  lens  is  placed  with  its 

110 


CHAP,  v.]  THE    CORNEA.  Ill 


principal  axis  in  the  direct  line  between  the  lamp  and  the  eye,  so 
that  the  light  may  be  concentrated  on  the  cornea.  By  withdrawing 
or  approaching  the  lens  a  little,  one  can  focus  the  light  on  the  surface, 
or  in  the  substance  of  the  cornea. 

3.  By  the  Combined  Focal  Method — that  is  focal  illumination 
as  above,  combined  with  the  use,  as  a  magnifying-glass,  of  a  second 
-f  14"0  lens.  The  second  lens  is  held  between  the  finger  and  thumb 
of  the  left  hand  some  inches  from  the  patient's  eye,  while  the  surgeon 
places  his  eye  at  the  focus  of  this  glass,  the  cornea  being  at  the 
same  time  illuminated  by  the  light  focussed  on  it  with  the  other 
lens  held  between  the  finger  and  thumb  of  the  right  hand,  or,  better 
still,  a  binocular  loupe  may  be  used  to  magnify  the  cornea.  Changes 
in  the  cornea  are  then  seen  magnified,  and  at  the  same  time  highly 
illuminated. 

4.  By  the  Ophthalmoscope  with  a  +  18*0  or  +  20*0  lens  behind 
the  sight-hole  of  the  mirror.  The  surgeon  proceeds  as  though  he 
were  about  to  examine  the  fundus  in  the  erect  image  (p.  30).  The 
cornea  is  illuminated  from  the  mirror,  and  changes  in  it  are  magnified 
by  the  +  lens  through  which  it  is  inspected.  Minute  irregularities 
of  the  surface  or  fine-dust-like  deposits  on  Descemet's  membrane 
may  be  made  out  by  this  method. 

5.  By  Fluorescine.  In  cases  of  ulcer,  or  any  abrasion  of  the 
corneal  epithelium,  when  it  is  desired  to  ascertain  accurately  the 
whole  extent  of  the  loss  of  substance,  or  if  there  be  some  doubt 
as  to  the  presence  of  such  a  lesion,  an  instillation  of  a  drop  of  fluor- 
escine solution  (Fluorescin,  gr.  ij,  Sodii  Carb.  gr.  j,  Aq.  destill.  3  ij) 
is  used.  About  half  a  minute  after  the  instillation  the  excess  should 
be  washed  away,  when  the  whole  region  which  is  denuded  of  epithe- 
lium will  be  seen  stained  of  a  greenish  yellow  colour.  In  some  instances 
where  there  is  no  true  loss  of  substance,  staining  takes  place  if 
the  epithelium  be  not  sound.  An  ulcer,  which  in  the  process  of 
healing  has  become  covered  with  sound  epithelium,  will  not  stain, 
although  there  may  still  remain  some  loss  of  substance  to  be  filled 
up.  Fluorescine  does  not  harm  the  cornea,  nor  interfere  with  healing 
of  any  diseased  process  in  it,  and  the  staining  disappears  after  a  short 
time.  A  pretty,  and  in  some  cases  practically  useful,  method  is  v. 
Keuss's  double  staining.  After  the  lesion  has  been  stained,  as 
above,  with  fluorescine,  a  drop  of  a  1  per  cent,  solution  of  methylene 
blue  (medicinal)  is  instilled,  with  the  result  that  the  general  floor  of 


112  DISEASES  OF   THE  EYE.  [chap.  v. 

the  lesion — i.e.  the  denuded  corneal  tissue — becomes  blue,  while  the 
margin — i.e.  the  loosened  epithelium — remains  of  the  greenish- 
yellow  colour. 

The  foregoing  methods  are  in  everyday  use. 

6.  By  the  Corneal  Microscope.  This  is  an  elaborate  optical 
instrument,  which  forms  the  outfit  of  a  well-equipped  ophthalmic 
hospital,  and  is  adapted  for  the  minute  study  of  diseased  states 
of  the  cornea  and  iris.  It  is  not  needed  for  ordinary  clinical  work, 
and  therefore  a  description  of  it  will  not  be  given  here. 

Inflammations  of  the  Cornea. 

From  a  clinical  standpoint  these  inflammations  will  be  most 
conveniently  considered  under  the  headings — {a)  Ulcerative  In- 
flammations, and  (6)  Non-ulcerative  Inflammations. 

(a)  Ulcerative  Inflammations  of  the  Cornea. — Ulceration 
of  the  cornea  is  preceded  by  a  cellular  infiltration ,  usually  near  the 
anterior  surface  ;  this  keratitis  is  brought  about,  in  most  instances, 
if  not  in  all,  by  the  entrance  into  the  cornea — through  the  blood,  or 
through  a  traumatic  loss  of  substance  of  the  surface  of  the  cornea — 
— of  certain  micro-organisms  : — pneumococci,  diplobacilli  of  Morax, 
staphylococci,  streptococci,  bacillus  subtilis,  etc.  One  recognises 
the  existence  of  an  infiltration  by  seeing  an  opaque  spot  in  the  cornea, 
with  a  dullness  of  the  layers  over  it,  and  often  also  of  the  correspond- 
ing part  of  the  epithelium.  Before  long  the  epithelium  covering  the 
infiltration  undergoes  necrosis  and  comes  aw^ay,  and  soon  the  inter- 
vening layers  of  the  true  cornea  also  break  down,  and  in  this  way  an 
ulcer  becomes  established. 

But  although  all  ulcers  of  the  cornea  originate  in  an  infiltration, 
yet,  once  established,  they  assume  great  varieties  of  type,  in  con- 
sequence, probably,  of  varieties  in  the  nature  of  the  originating 
micro-organisms.  Some  ulcers  are  purulent,  others  non-purulent ; 
some  tend  to  spread  over  the  surface  of  the  cornea,  others  tend  to 
go  deep  into  it ;  the  progress  of  some  is  very  rapid,  and  of  others 
exceedingly  chronic  ;  some  attack  by  preference  the  central  region 
of  the  cornea,  while  others  are  confined  to  its  margin  ;  some  readily 
give  way  to  treatment,  and  others  are  very  obstinate  or  even  in- 
curable. Again,  some  ulcerative  corneal  processes  are  attended 
by  much  irritation  :    that  is  to  say,  circumcorneal  injection,  severe 


CHAP,  v.]  THE   CORNEA.  11.1 

pain  in  and  about  the  eye,  great  reflex  blepharospasm,  and  lacrima- 
tion  ;  whilst  others,  which  may  really  be  more  severe  processes  in 
so  far  as  the  integrity  of  the  eye  is  concerned,  can  run  their  course 
with  hardly  any  injection  of  the  eyeball,  and  with  little  or  no  distress 
to  the  patient. 

Etiologicalhj,  corneal  ulcers  are  primary  or  secondary.  The 
primary  ulcers  are  those  in  which  the  diseased  process  originates 
in  the  cornea,  most  commonly  as  the  result  of  traumata,  but  also 
in  phlyctenular  keratitis,  or  as  the  result  of  corneal  abscess,  or 
w^here  the  nutrition  of  the  cornea  is  interfered  with,  etc.  Secondary 
ulcers  are  those  which  are  the  result  of  disease  elsewhere,  usually 
in  the  conjunctiva,  as  in  acute  blennorrhoea  and  in  conjunctival 
diphtheritis. 

Corneal  ulcers  are  more  common  in  advanced  than  in  early  life. 
Indeed,  in  early  life,  unless  in  cases  of  infantile  ulceration  with 
conjunctival  xerosis,  of  blennorrhoea  neonatorum,  and  of  phlyc- 
tenular disease,  corneal  ulcers  are  almost  unknown.  The  greater 
liability  to  these  affections  in  advanced  life  is  due,  it  may  be  assumed, 
to  a  less  active  nutrition  at  that  period  in  this  already  lowly  organised 
part.  Hence  slight  traumata,  or  the  presence  of  a  slight  conjunctival 
catarrh,  which  would  have  no  ill  effect  in  a  young  person,  may  form 
the  starting-point  of  a  corneal  ulcer  in  an  old  person,  or  even  in  one 
of  middle  age.  For  the  same  reasons,  corneal  ulcers  are  much  more 
common  in  the  poorer  classes  than  amongst  the  well-to-do  ;  for 
their  general  nutrition  is  often  defective,  while  they  are  more  exposed 
to  traumata  than  are  the  better  classes. 

The  Diagnosis  of  the  presence  of  a  large  corneal  ulcer  is  simple. 
Inspection  of  the  cornea  in  ordinary  daylight  at  once  reveals  the 
loss  of  substance,  more  or  less  extensive,  deep,  or  infiltrated.  If 
the  ulcer  be  very  small  and  shallow  the  difficulty  is  greater,  especially 
if  there  be  much  blepharospasm.  An  instillation  of  cocaine  may  be 
necessary  to  facilitate  the  examination. 

It  is  obviously  important  to  decide  at  the  outset,  for  the  purposes 
of  prognosis  and  of  treatment,  whether  a  grey  spot  in  the  cornea 
be  a  keratitis  (a  cellular  infiltration  which  may  shortly  break  down 
and  become  an  ulcer),  an  ulcer,  or  a  scar  (the  result  of  an  ulcer, 
or  other  loss  of  substance).  The  surface  covering  an  infiltration, 
although  flush  with  the  general  surface  of  the  cornea,  has  usually 
a  steamy  appearance,  due  to  disorganisation  of  the  corneal  epithe- 
8 


14  DISEASES   OF    THE   EYE.  [chap,  v 


lium,  and  has  no  lustre.  With  an  ulcer  the  appearances  already 
described  will  be  found.  The  surface  of  a  scar  is  usually,  although 
not  always,  flush  with  the  general  surface  of  the  cornea,  and  it  has 
a  bright  surface — i.e.  covered  with  normal  epithelium,  not  rough, 
irregular,  nor  even  steamy.  A  scar,  moreover,  is  generally  more 
defined  at  its  edges,  and  is  either  pure  white  if  opaque,  or  bluish 
white  if  translucent.  In  cases  of  corneal  infiltration,  or  ulceration, 
there  usually  will  be  more  or  less  pericorneal  injection,  pain,  and 
photophobia,  while  with  a  mere  corneal  scar  there  will  be  no  irrita- 
tion of  the  eye.  Fluorescine  stains  an  ulcer,  and  sometimes  an 
infiltration  if  it  be  near  the  surface,  but  not  a  cicatrix. 

The  presence  of  Hijfopyon  {vtto,  under  ;  ttvoi',  pus)  is  the  rule 
with  several  types  of  corneal  ulcer,  notably  the  deep  ulcer,  and  the 
serpiginous  ulcer.  The  term  '  hypopyon  ulcer,'  Avhich  is  so  much 
used,  should  certainly  be  discarded,  as  hypopyon  is  not  the  charac- 
teristic of  one  type  of  ulcer.  Hypopyon  is  a  deposit  of  pus  in  the 
anterior  chamber,  and  as  the  patient  sits  or  stands  it  lies  in  the 
lowest  part  of  the  chamber,  to  which  place  it  has  gravitated.  If  the 
patient  lie  in  bed,  say  on  the  side  of  the  affected  eye,  the  hypopyon 
will  of  course  change  its  position,  and  gravitate  towards  the  temporal 
side  of  the  chamber.  Sometimes  the  hypopyon  is  so  small  as  to 
be  detected  with  difficulty  ;  and  again  it  may  fill  the  whole  anterior 
chamber,  completely  obscuring  the  iiis  and  rendering  a  diagnosis 
of  the  condition  of  the  cornea  difficult.  The  pus  cells  in  hypopyon 
do  not  come  from  the  ulcer,  but  are  due  to  the  presence  of  toxin  in 
the  anterior  chamber,  which  causes  an  exudation  of  polymorpho- 
nuclear leucocytes  from  the  vessels  of  the  iris  and  ciliary  body.  These 
cells  are  unable  to  make  their  way  to  the  cornea  owing  to  the  mem- 
brane of  Descemet,  and  fall  to  the  bottom  of  the  anterior  chamber. 
The  pus  forming  a  hypopyon  is  sterile',  unless,  in  the  later  stages, 
the  cornea  be  perforated. 

The  Dangers  attendant  upon  Corneal  Ulcers  are,  first  of  all,  the 
opacities,  the  scars,  which  even  the  slightest  of  them  are  apt  to 
leave  behind. 

Fig.  52  represents  a  section  made  through  a  deep  ulcer  in  its 
progressive  stage.  At  the  margin  of  the  ulcer  the  epithelium  (e) 
and  Bowman's  membrane  (b)  cease.  The  floor  of  the  ulcer  is  seen 
covered  with  pus,  which  also  infiltrates  the  corneal  tissue  beneath 
the  floor  and  around  the  margin.     As  soon  as  cure  commences  the 


CHAP.    V.J 


THE    CORNEA. 


115 


floor  of  the  ulcer  begins  to  clear,  i.e.  it  becomes  gradually  less  covered 
with  pus,  until  it  is  finally  quite  free  from  it,  and  'pari  passu  the  sur- 
rounding infiltration  of  the  cornea  is  absorbed.  Then  the  epithe- 
lium, growing  in  from  the  margin  {m  m,  Fig.  53)  all  around,  gradually 


Fig.  52.   {Fuchs.) 

carpets  over  the  floor  of  the  ulcer,  and  underneath  this  newly  formed 
epithelium  the  new  tissue,  which  is  to  close  in  the  loss  of  substance,  is 
laid  down.  This  new  tissue,  however,  is  not  normal  corneal  tissue, 
but  is  ordinary  connective  tissue,  and  is  therefore  opaque.  Hence 
the  deeper  the  ulcer,  the  more  intense  will  be  the  resulting 
opacity.  Bowman's  membrane  never  becomes  restored  over  the 
cicatrix. 


Fig.   53.   (Fuchs.) 

The  ulcers  which  are  situated  at  the  centre  of  the  cornea,  in 
the  pupillary  area,  are  more  serious  for  sight  than  those  situated 
peripherally,  as  can  be  readily  understood.  The  opacity  left  by 
a  very  superficial  ulcer  is  slight,  and  is  called  a  nebula  ;   a  somewhat 


16  DISEASES    OF    THE   EYE.  [ohap.  v. 


more  intense  opacity  is  called  a  macula  ;  and  a  very  marked  white 
scar  is  called  a  leucoma. 

But  a  more  serious  danger  connected  with  ulcers  of  the  cornea 
than  the  opacities  they  leave  behind  is  that  of  perforation  of  the 
cornea,  to  which  some  ulcers  are  very  prone.  The  consequences 
of  perforation  are  :  prolapse  of  iris  resulting  in  anterior  synechia^, 
adherent  leucoma,  or  staphyloma  of  the  cornea,  and  fistula  of  the 
cornea. 

Treatment. — In  the  treatment  of  primary  corneal  ulcers  the 
student  will  soon  observe  that  a  bandage,  atropine,  and  warm 
fomentations  play  prominent  parts  ;  and  these  routine  measures 
alone  are  sufficient  to  produce  cure  in  the  less  severe  cases. 

The  bandage  should  be  put  on  w4th  firm  pressure — but  should 
not  be  made  uncomfortably  tight — the  eye  having  been  previously 
padded  out,  especially  at  the  inner  canthus,  so  that  equal  pressure 
may  be  exercised  all  over  the  globe.  The  support  thus  given  to 
the  cornea  and  front  of  the  eye  promotes  the  healing  process,  and 
the  bandage  is  also  useful  by  preventing  the  eyelids  from  rubbing 
over  the  ulcer,  and  by  protecting  it  from  foreign  bodies.  In  those 
secondary  ulcers,  which  are  due  to  conjunctival  processes,  such  as 
catarrhal  conjunctivitis  or  blennorrhoea,  a  bandage  is  contra- 
indicated,  because  it  retains  the  secretion,  and  would  therefore  do 
harm  rather  than  good. 

Atropine  in  sufficient  quantities  to  keep  the  pupil  dilated  should 
be  employed.  Iritis  very  often  attends  severe  corneal  ulcers,  and 
here  the  indication  for  atropine  is  obvious.  But  rest  of  the  affected 
part  is,  we  know,  an  important  element  in  preventing  or  in  curing 
any  inflammation  ;  and  in  the  affections  we  are  now  treating  of, 
even  if  there  be  no  iritis,  atropine  acts  by  procuring  rest  of  the 
iris  and  of  the  ciliary  muscle. 

Miotics  are  preferred  by  some  to  mydriatics  in  the  treatment 
of  corneal  ulcers,  on  the  ground  that  the  action  of  miotics  in  reducing 
the  intra-ocular  tension  promotes  healing,  and  that  the  more  ex- 
tended surface  of  iris — more  extended  absorbing  surface — facilitates 
absorption  of  hypopyon.  It  is  not  certain  that  miotics  do  reduce 
the  normal  tension,  and  in  these  cases  they  undoubtedly  increase 
the  tendency  to  iritis.  As  to  absorption  of  the  hypopyon,  it  will 
come  about  in  due  course  when  the  cornea  begins  to  recover.  Yet 
a  clear  indication  for  miotics  is  given  by  the  presence  of  an  ulcer 


CHAP,  v.l  THE    CORNEA. 


near  the  corneal  margin,  which  has  a  tendency  to  perforate,  for 
here  the  miosis  would  assist  in  preventing  prolapse  of  the  iris, 
should  perforation  take  place. 

Dionine  is  useful  in  the  treatment  of  many  cases  of  primary 
corneal  ulceration  and  other  primary  corneal  diseases.  Its  physio- 
logical action  is  to  cause  dilatation  of  the  blood  vessels  of  the  con- 
junctiva with  great  chemosis — although  it  does  not  act  equally 
well  in  every  eye — and  its  therapeutic  effect  is  held  to  depend  on 
this  lymphatic  flooding  of  the  front  of  the  eye.  It  is  used  in  a 
5  per  cent,  solution  dropped  into  the  eye  once  a  day,  but  stronger 
solutions  or  even  the  powder  itself  may  be  applied  by  the  surgeon 
if  necessary.  If  employed  frequently  it  ceases  to  produce  any 
reaction,  and  for  this  reason  it  may  be  desirable  in  some  cases  to 
use  it  once  only  on  alternate  days.  It  causes  slight  ansethesia  of 
the  cornea. 

Warm  fomentations  promote  the  healing  process  by  stimulating 
tissue-changes  in  the  cornea.  One  usually  orders  them  to  be  made 
with  poppy-head  water  or  camomile  tea,  although  no  doubt  warm 
sterilised  water  would  be  equally  efficacious.  Hot  solutions  of 
4  per  cent,  boric  aid,  or  1  in  5000  corrosive  sublimate,  may  be  used 
with  advantage.  A  compress  of  cotton  wool  which  has  been  dipped 
in  the  stupe  at  about  120°  Fahr.  is  laid  upon  the  eye,  and  frequently 
replaced  by  fresh  compresses  out  of  the  stupe,  so  that  the  compress 
on  the  eye  may  always  be  hot.  This  is  continued  for  half  an  hour 
at  a  time,  and  repeated  every  two  or  three  hours.  Or,  the  Japanese 
muff-warmer,  or  a  special  electric  warmer,  may  be  applied. 

In  an  ulcer  of  a  purulent  or  sloughing  nature,  the  insuffiation 
on  its  floor  of  very  finely  divided  xeroform  or  iodoform  powder  is 
useful.  A  purulent  ulcer  may  be  cleansed  with  hydrogen  peroxide, 
or  touched  with  pure  carbolic  acid,  tincture  of  iodine,  or  20  per  cent, 
sulphate  of  zinc.  A  quinine  derivate,  ethyl  hydrocuprein  (optochin) 
in  1  per  cent,  solution  is  especially  useful  in  pneumococcus  ulcers. 
Scarlet-red  ointment  (1  in  20)  we  have  also  seen  do  good. 

When  more  active  measures  than  the  foregoing  are  called  for, 
the  actual  cautery,  curetting,  paracentesis,  and  subconjunctival 
injections  of  oxycyanide  of  mercury  (5  min.  of  a  1  in  5000  solution) 
have  to  be  resorted  to. 

The  actual  cautery  is  much  in  use  in  the  treatment  of  serpiginous 
and  other  infected  corneal  ulcers.     It  acts  by  destroying  the  micro- 


DISEASES    OF   THE   EYE. 


[chap.  v. 


\ 


t.^ 


II 


organisms,  which  keep  the  process  going.  Either  a  thermo-cautere, 
in  the  form  of  a  very  fine  point,  or  the  galvano-cautery  (Fig.  54), 
the  platinum  wire  being  at  a  red-heat,  may  be  employed.  The  eye 
having  been  cocainised,  the  red-hot  point  is 
brought  into  contact  with  the  whole  surface  of 
the  ulcer,  so  as  to  thoroughly  destroy  its  super- 
ficial layer,  and  special  attention  is  given  to  any 
part  of  the  margin  of  the  ulcer  where  there  is  a 
tendency  to  spread  to  as  yet  healthy  tissue. 
Fluorescine  may  be  used  to  show  the  exact  ex- 
tent of  the  ulcerated  surface.  The  cauterisation 
can  be  repeated  as  often  as  the  state  of  the  ulcer 
may  make  it  desirable.  It  is  sometimes  well  to 
perforate  the  cornea  with  the  cautery,  and  to 
evacuate  the  aqueous  humour  and  hypopyon  ;  or 
this  may  be  done  with  an  ordinary  paracentesis 
needle,  after  the  cauterisation  is  completed.  The 
cautery  gives  a  good  percentage  of  cures  with  the 
least  amount  of  opacity. 

Thorough  curetting  of  the  floor  of  the  ulcer 
with  a  small  sharp  spoon  is  a  valuable  method, 
either  alone  or  prior  to  cauterisation. 

Paracentesis  of  the  anterior  chamber  through 
the  floor  of  the  ulcer  is  another  most  valuable 
therapeutic  measure  for  some  corneal  ulcers,  and 
deserves  a  more  routine  application  in  these  cases 
than  is  accorded  to  it ;  the  more  so  as  the  little 
operation  is  simple  and  dangerless.  But  there  are 
two  indications  for  its  use  which  should  be  re- 
garded as  imperative — namely,  (1)  If  there  be 
great  pain.  8oon  after  the  operation,  which  for  a 
short  time  increases  the  neuralgia,  the  patient  ex- 
periences great  relief,  and  passes  the  first  good 
night  after  many  wakeful  ones.     (2)  If  perforation 

Fig.  54. — The  bolt  B  being  pushed  forwards,  the 

circuit  is  completed.     By  pressure  on  the  button  A  the 

current  can  be  momentarily  intercepted  during  use  of 

the   instrument.      There    are   other   good  patterns  of 

Fig.  54.  galvano-cautery. 


I 


CHAP,  v.]  THE   CORNEA.  119 

seem  to  be  imminent.  This  may  often  be  recognised  by  a  bulging 
forwards  of  the  thin  floor  of  the  ulcer  ;  but  sometimes  it  is  not 
easily  foreseen,  and  if  there  be  any  doubt  on  the  point,  paracentesis 
should  be  performed.  It  is  important  to  forestall  spontaneous 
perforation  of  the  ulcer  by  this  proceeding,  because  the  opening 
that  is  made,  being  linear,  heals  easily,  and  leaves  but  a  slight  scar 
without  anterior  synechioe ;  while  the  natural  opening 
would  be  a  complete  loss  of  substance,  and  would,  there- 
fore, the  more  readily  involve  adhesion  of  the  iris  in  the 
resulting,  and  comparatively  extensive,  cicatrix.  Other 
indications  for  the  operation  are  increased  tension,  and 
the  presence  of  a  large  hypopyon. 

Paracentesis  of  the  anterior  chamber  is  best  performed 
by  means  of  a  paracentesis  needle  (Fig.  55),  which  is  a 
small  somewhat  shovel-shaped  blade.  If  this  be  not  at 
hand,  a  small  keratome,  or  a  broad  needle,  or  a  Grsefe's 
cataract  knife  will  answer  the  purpose.  The  eye  having 
been  cocainised,  a  spring  lid-speculum  is  inserted,  the 
conjunctiva  near  the  cornea  is  grasped  with  a  fixation 
forceps,^  if  necessary,  and  the  point  of  the  paracentesis 
needle  applied  to  the  floor  of  the  ulcer,  in  such  a  way  that 
the  plane  of  the  little  blade  may  be  at  an  angle  of  about 
45°  with  that  of  the  floor  of  the  ulcer.  The  point  is  pushed 
gently  through  the  floor,  and  the  plane  of  the  blade  is  then 
immediately  changed,  so  that,  as  the  instrument  is  being 
advanced  up  to  the  hilt,  it  may  be  almost  in  contact  with 
the  posterior  surface  of  the  cornea.  The  instrument  should 
be  withdrawn  very  slowly,  in  order  that  the  aqueous 
humour  may  flow  oii  gradually,  and  not  with  a  rush.  If 
these  precautions  be  taken,  there  need  be  no  danger  of 
injury  to  the  crystalline  lens,  or  of  prolapse  of  the  iris  into  ^^^^ 
the  incision.  Should  prolapse  occur,  it  can  usually  be  re- 
posed with  the  spatula.  It  may  happen  that  when  the  needle  has 
been  withdrawn  a  considerable  portion  of  the  aqueous  humour  may 
remain  in  the  anterior  chamber,  unable  to  escape  owing  to  the 
valve-like  closure  of  the  wound.     It  should  be  evacuated  by  making 

1  If  the  eye  be  much  congested  and  very  painful,  a  few  ch-ops  of  cocaine 
can  be  injected  subconjunctivally  at  the  point  where  it  is  intended  to 
apply  the  fixation  forceps. 


120  DISEASES    OF    THE   EYE.  [chap.  v. 

the  wound  gape  by  gentle  pressure  with  a  spatula  on  its  posterior 
lip.  If  it  be  desirable  to  tap  the  anterior  chamber  on  the 
next  day,  this  can  be  done  by  simply  opening  up  the  wound 
with  a  spatula,  or  with  the  probe-like  instrument  at  the  other 
end  of  the  handle  (Fig.  55),  without  the  aid  of  any  cutting  in- 
strument. 

Subconjunctival  injections  of  solution  of  oxycyanate  of  mercury 
(1  in  5000)  or  of  solution  of  chloride  of  sodium  (4  per  cent.)  enter 
largely  into  the  therapeutics  of  corneal  disease,  and  of  disease  in 
the  uveal  tract.  It  makes  the  little  operation  much  less  disagreeable 
for  the  patient  if  a  speculum  and  forceps  be  dispensed  with.  With  a 
sharp  needle  there  is  no  difficulty  in  thrusting  the  point  under  the 
conjunctiva.  It  should  be  entered  near  the  fornix,  certainly  not 
close  to  the  cornea.  It  is  not  necessary  that  the  injections  should  be 
made  under  the  capsule  of  Tenon  as  was  at  first  supposed.  The 
mode  of  action  of  these  injections  is  not  clearly  understood.  It  is 
not  due  to  the  entrance  of  the  preparations  into  the  tissue  of  the 
cornea  or  interior  of  the  eye,  for  only  minimal  quantities  of  even 
mercurial  salts  have  been  found  in  the  vitreous  humour.  It  was 
at  first  believed  that  they  acted  as  lymphagogues,  but  their  curative 
power  is  now  held  to  depend  on  the  vascular  reaction  to  which  they 
give  rise.  Of  the  oxycyanate  of  mercury  solution  5  to  10  minims 
according  as  it  can  be  borne,  or  of  the  saline  solution  10  to  20 
minims,  are  injected  under  the  bulbar  conjunctiva  in  the  direction 
away  from  the  cornea.  Other  solutions  (sublimate,  hetol,  cyanate 
of  mercury,  iodipin,  iodide  of  potash,  etc.)  have  been  employed, 
but  these  two  are  as  efficacious  as  any.  From  2  to  5  minims  of  a 
1  per  cent,  solution  of  acoine  may  be  taken  up  in  the  syringe  with 
the  main  solution,  just  before  the  injection  is  made,  in  order  to 
diminish  the  severe  pain  and  irritation  which  come  on  afterwards, 
and  last  often  for  several  hours.  This  pain  may  be  much  relieved 
by  hot  fomentations,  but  if  it  be  very  intense  a  hypodermic  injection 
of  morphia  may  be  necessary.  Or,  if  one  or  two  drops  of  a  4  per 
cent,  solution  of  dionine  be  instilled  into  the  eye,  followed  a  few 
minutes  later  by  an  instillation  of  a  4  per  cent,  solution  of  cocaine, 
a  subconjunctival  saline  injection  may  be  made  almost  painlessly. 
Considerable  vascular  injection  and  chemosis  may  be  present  next 
day,  and  the  eyelids  may  be  swollen  and  oedematous.  The  injection 
should  not  be  repeated  until  the  redness  and  oedema  have  almost 


THE    CORNEA.  121 


subsided.  Few  eyes  require,  or  can  tolerate,  more  than  two  in- 
jections in  the  week.     (See  also  chap,  xi.) 

If  the  case  do  not  come  under  the  care  of  the  surgeon  until 
perforation  of  the  ulcer  with  prolapse  of  the  iris  has  taken  place, 
the  important  question  as  to  the  best  method  of  dealing  with  the 
condition  is  presented.  If  the  loss  of  substance  should  occupy  one 
third  or  more  of  the  cornea  with  correspondingly  large  prolapse 
of  iris,  the  development  of  a  staphyloma  is  almost  inevitable. 
Eserine  is  to  be  used  to  reduce  the  intra-ocular  pressure,  and  a  firm 
bandage  is  to  be  kept  applied  to  the  eye.  And  here  transplantation 
of  conjunctiva  over  the  ulcer  and  prolapsed  iris,  to  strengthen  the 
cicatrix  (see  below),  is  indicated.  But  if  the  ulcer  and  prolapse  be 
small,  an  attempt  may  be  made  to  free  the  iris,  so  that  no  anterior 
synechia  may  form,  and  in  order  that  the  cicatrix  may  be  flat, 
and  not  raised  over  the  surface  of  the  cornea,  and,  consequently, 
exposed  to  injury.  The  importance  of  such  an  attempt  lies  in  the 
fact  that  a  corneal  cicatrix  with  iris  entangled  in  it — not  merely 
adherent  to  its  posterior  surface — affords  a  constant  source  of 
danger,  especially  if  situated  near  the  margin  of  the  cornea  ;  for 
in  such  eyes,  it  may  be  years  later,  sudden  and  uncontrollable 
purulent  inflammation  of  the  iris  and  chorioid  may  come  on  from 
septic  infection,  after  an  apparently  slight  trauma  of  the  cicatrix, 
and  may  rapidly  end  in  total  destruction  of  the  eye.  The  surgeon's 
attention  should  therefore  be  directed  to  obtain  at  least  as  flat  a 
cicatrix  as  possible,  or,  still  better,  a  non-adherent  cicatrix.  The 
practice  which  is  commonly  follow^ed,  is  to  draw  the  freshly  pro- 
lapsed portion  of  iris  slightly  forwards  with  a  forceps,  and  to  snip 
it  ofi  level  with  the  surface  of  the  cornea  ;  and  then  with  a  spatula 
to  endeavour  to  free  the  iris  from  any  adhesions  it  may  have  formed 
with  the  margin  of  the  ulcer.  Atropine  or  eserine,  according  to  the 
position  of  the  ulcer,  is  then  instilled,  and  a  bandage  carefully 
applied.  This  proceeding  is  only  of  use  when  a  fresh  prolapse 
can  be  dealt  with,  before  cicatrisation  sets  in  ;  and  the  result  is 
often  satisfactory  in  so  far  as  the  securing  of  a  flat  cicatrix  is  con- 
cerned, but  an  anterior  synechia  can  rarely  be  avoided. 

Kuhnt's  method  for  strengthening  the  cicatrix,  where  an  exten- 
sive ulceration  with  prolapse  is  present,  by  means  of  a  conjunctival 
flap,  with  single  or  double  pedicle,  which  is  drawn  over  the  ulcer, 
is  aValuable_one.     If,  for  example,  the  ulcer  and  prolapse  be  at  a 


122 


DISEASES   OF    THE   EYE. 


[chap.  v. 


(Fig.  56),  an  incision  6  c  is  made  through  the  conjunctiva  along 
the  margin  of  the  cornea,  and  an  incision  d  e  more  peripherally, 
or  it  is  perhaps  better  to  make  the  peripheral  incision  first.  The 
flap  so  outlined  is  dissected  up,  drawn  over  the  cornea,  ulcer,  and 
prolapse  of  iris,  and  then  secured  in  its  new  position  by  means  of 
a  suture  (/,  Fig.  57).  In  forming  the  conjunctival  flap,  care  should 
be  taken  to  obtain  it  with  as  little  subconjunctival  tissue  adherent 
to  it  as  possible.  In  a  few  days  the  flap  becomes  adherent  to  the 
ulcer  and  prolapse,  and  its  upper  and  lower  positions  can  then  be 
released  with  the  scissors.  By  this  means  a  stronger  covering 
for  the  ulcer  and  prolapse  is  provided,  and  the  dangers  of  late 
infection  and  of  staphyloma  are  minimised.     A  flap  with  a  single 


d 


Fig.   50. 


Fig.   57. 


pedicle  may  also  be  used,  or  the  conjunctiva  may  be  loosened  at  the 
limbus  and  drawn  over  the  ulcer  by  sutures  above  and  below,  or 
even  made  to  cover  the  whole  cornea  by  a  purse- string  suture. 

Different  types  of  corneal  ulcers  are  recognised  and  described. 
Of  these  the  following  are  the  chief  :— 

Simple  Ulcer. — This  may  result  from  a  slight  trauma,  or  it  may 
originate  in  a  phlyctenula.  It  presents  the  appearance  on  the 
surface  of  the  cornea  of  a  minute  and  shallow^  depression  w^ith  a 
grey  floor.  There  is  circumcorneal  vascularity,  especially  at  that 
part  of  the  corneal  margin  nearest  to  which  the  ulcer  is  situated  ; 
the  pupil  is  apt  to  be  contracted,  although  iritis  is  not  present, 
and  there  is  often  a  good  deal  of  pain,  lacrimation,  and  photophobia. 

Treatment  and  Prognosis. — The  eye  is  to  be  bandaged,  warm 
fomentations  applied  several  times  a  day,  and  a  drop  of  solution 


CHAP,  v.]  THE   CORNEA.  123 

of  atropine  instilled  night  and  morning.  When  of  phlyctenular 
origin,  stimulation  with  the  yellow  oxide  ointment  is  indicated. 
Dionine  may  be  used.  Cure,  with  slight  opacity  remaining,  comes 
about  in  a  week  or  ten  days.  But,  if  it  become  infected,  this  form 
of  ulcer  may  pass  over  to  the  deep  ulcer. 

Deep  Ulcer. — This  is  a  septic  or  infected  ulcer,  and  commences 
in  a  septic  infiltration  of  the  cornea.  It  forms  a  tolerably  deep  pit 
in  the  cornea  towards  its  centre,  the  floor  of  the  ulcer  being  covered 
with  purulent  deposit  and  detritus,  and  the  corneal  tissue  imme- 
diately surrounding  it  being  somewhat  infiltrated  with  pus.  The 
ulcer  is  generally  round,  but  it  may  assume  any  shape.  Hypopyon 
is  often  present,  and  a  marked  tendency  to  iritis  exists.  The  pain 
is  usually  very  severe,  violent  frontal  neuralgia  being  a  common 
symptom. 

This  ulcer  has  no  great  tendency  to  spread  over  the  surface  of 
the  cornea,  but  has  a  very  decided  tendency  to  perforate  through 
it.  As  it  does  not  generally  attain  w^ide  dimensions,  the  perforation 
it  may  produce  is  small,  and  gives  rise  to  a  small  adherent  leucoma 
rather  than  to  a  staphyloma.  It  seldom  causes  complete  loss  of 
the  eye. 

Causes. — This  form  of  ulcer  is  a  frequent  one  in  gonorrhoeal 
ophthalmia  and  in  blennorrhoea  neonatorum  ;  and  it  may  be  caused 
by  the  lodgment  of  foreign  bodies,  and  other  injuries  of  the  cornea. 

Treatment. — If  the  ulcer  be  due  to  a  conjunctival  process,  the 
latter  should  be  actively  treated,  and  the  only  attention  needed  for 
the  ulcer  is  to  anticipate  by  paracentesis  a  spontaneous  perforation. 

If  the  cause  be  other  than  conjunctival,  a  pressure  bandage 
to  give  support  to  the  ulcer  is  important,  and  periodical  w^arm 
fomentations  are  most  beneficial ;  but  where  the  cause  is  con- 
junctival (purulent  conjunctivitis),  neither  a  bandage  nor  warm 
fomentations  can  be  used.  Atropine  should  be  instilled  in  all  cases 
several  times  daily,  and  antiseptic  applications,  especially  xeroform, 
are  useful. 

Paracentesis  through  the  floor  of  the  ulcer  is  always  followed  by 
improvement,  and  is  important  as  a  preventive  of  natural  perforation. 
The  actual  cautery  may  be  necessary. 

Fistula  of  the  Cornea. — The  deep  ulcer  when  it  perforates  is 
the  most  common  cause  of  fistula  of  the  cornea.  A  fistula  presents 
the  appearance  of  a  very  small  black  spot  near  the  centre  of  a 


124  DISEASES    OF    THE   EYE.  [chap.  v. 

leucoma,  and  is  liable  to  form  when  the  perforating  ulcer  is  in  the 
pupillary  area  of  the  cornea,  so  that  it  cannot  be  perfectly  closed 
by  the  prolapse  of  iris  into  it.  In  this  position  the  ulcer  closes 
by  the  slow  growth  of  connective  tissue  from  its  margins,  and 
sometimes  this  process  does  not  go  on  to  completion,  and  a  small 
central  fistula  is  left.  Or,  the  perforation  is  so  situated,  that  just 
a  small  tag  of  the  pupillary  margin  of  the  iris  is  incarcerated  in  the 
cicatrix  ;  and  the  pulling  of  the  iris  on  this,  as  the  pupil  dilates, 
prevents  complete  closure  of  the  orifice.  Or,  if  the  perforation  be 
of  wide  area,  with  extensive  iris-prolapse,  the  pressure  of  aqueous 
humour  may  cause  a  small  rupture  in  the  prolapse  which  may 
not  heal  again.  Through  the  fistula,  however,  it  may  occur,  aqueous 
humour  constantly  trickles  away,  the  anterior  chamber  remains  very 
shallow  or  quite  empty,  the  globe  is  soft,  and  gradually  becomes 
softer  ;  or,  the  fistula  closes  for  a  time,  the  eye  then  becoming  of 
glaucomatous  hardness,  and  the  high  tension  luptures  the  cicatrix, 
which  again  closes,  and  is  again  ruptured  by  high  tension.  Finally, 
sight  is  lost  through  secondary  glaucoma,  detachment  of  the  retina, 
or  severe  uveitis  or  haemorrhage. 

Fistula  of  the  cornea  is  very  difficult  of  cure.  The  treatment 
consists  in  the  use  of  a  myotic  to  keep  the  intra-ocular  tension  low. 
With  the  same  object  an  iridectomy  is  indicated,  but  is  difficult 
of  performance  owing  to  the  shallow  anterior  chamber.  An  iri- 
dectomy may  also  be  indicated  to  withdraw  a  tag  of  the  margin 
of  the  pupil,  which  may  be  engaged  in  the  fistula.  The  margins  of 
the  fistula  may  be  curetted,  or  cut  away,  or  cauterised,  but  the 
close  proximity  of  the  lens  must  be  borne  in  mind,  lest  its  capsule 
be  mjured  by  these  proceedings.  After  curetting,  a  conjunctival 
flap  with  pedicle  may  be  transplanted  over  the  opening  (p.  122) ; 
the  flap  by  healing  to  the  curetted  margin  aids  in  the  closure  of 
the  fistula.  Or,  into  the  opening,  the  margins  of  which  have  been 
previously  curetted,  a  small'  flap  of  conjunctiva  without  pedicle 
may  be  pushed,  which,  healing  in  it,  closes  the  opening. 

Serpiginous  Ulcer  (Pneumococcus  Ulcer,  Ssemisch's  Ulcer). — 
This  is  a  purulent  ulcer,  with  a  characteristic  tendency  to  creep 
over  the  surface  of  the  cornea,  especially  in  some  one  direction, 
rather  than  to  strike  deep  into  its  tissue.  It  originates  in  a  superficial 
infiltration  or  abscess,  wliich  rapidly  ulcerates.  Its  position  is  chiefly 
central,  and  it  presents  a  greyish  floor,   which  is  more  intensely 


CH.\p.  v.]  THE   CORNEA.  125 

opaque  at  some  places.  One  part  of  the  margin  takes  the  form  of  a 
curve,  or  of  several  closely  placed  curves,  and  becomes  there  yellow- 
ish white  in  colour  and  somewhat  raised,  and  the  floor  of  the  ulcer 
seems  deeper  in  its  neighbourhood.  Immediately  around  the  ulcer 
the  cornea  is  slightly  opaque,  but  farther  out  it  is  normal. 

The  pain  and  irritation  vary  much  in  degree,  being  almost 
absent  in  some  cases,  while  in  others  they  are  intense.  Iritis  is 
apt  to  come  on  at  an  early  period,  and  may  pass  into  irido-cyclitis. 
Hypopyon  is  almost  always  present.  On  the  posterior  surface  of  the 
cornea,  from  the  region  corresponding  with  the  ulcer  on  the  anterior 
surface,  a  line  of  pus  is  sometimes  seen  extending  down  to  the 
hypopyon,  and  this  was  formerly  taken  as  a  proof  that  the  hypopyon 
was  formed  by  direct  transmission  of  the  pus  corpuscles  through 
the  cornea  from  the  ulcer.  The  ulcer  creeps  over  the  surface  of 
the  cornea  in  the  direction  of  the  curved  and  more  intensely  infil- 
trated portion  of  the  margin — the  progressive  margin — while  the 
opposite  side  of  the  margin  tends  to  become  cleaner.  At  a  still 
later  stage  the  whole  cornea  is  apt  to  become  infiltrated,  and  the 
entire  margin  of  the  ulcer  to  extend,  and  the  anterior  chamber 
becomes  quite  full  of  pus.  Perforation  now  takes  place,  or  may 
do  so  somewhat  earlier.  If  the  perforation  be  small,  an  adherent 
leucoma  results  ;  but  if  large,  a  staphyloma  of  the  cornea  gradually 
develops,  or  panophthalmitis  may  immediately  follow  on  the 
perforation. 

Causes. — Ulcus  Serpens  always  has  its  origin  in  a  trauma,  which 
has  produced,  it  may  be,  only  an  abrasion.  In  perhaps  50  per 
cent,  of  the  cases  chronic  dacryocystitis  is  present,  and  in  about  25 
per  cent,  more  there  is  ozoena,  and  a  considerable  proportion  of  them 
occur  in  the  warm  summer  months.  It  is  a  disease  of  the  poorer 
classes,  is  seldom  seen  in  children,  is  most  common  between  the 
ages  of  forty  and  seventy,  and  is  more  common  in  men  than  in 
women. 

In  most  instances  the  pneumococcus — which  is  usually  present 
in  the  discharge  in  chronic  dacryocystitis — is  the  excitant  of  the 
typical  ulcus  serpens,  but  occasionally  cases  have  been  observed  in 
which  the  pneumococcus  was  not  present,  and  the  diplobacillus 
liquefaciens,  the  streptococcus,  the  bacillus  subtilis,  or  some  rarer 
form  of  micro-organism,  was  the  excitant. 

Prognosis. — From  the  description  given,  it  will  be  seen  that  the 


126  DISEASES    OF    THE    EYE.  [chap.  v. 


process  is  a  severe  one  in  very  many  cases,  and  tlie  prognosis  for 
vision,  or  it  may  even  be  for  retention  of  the  eyeball,  very  serious. 
Yet  cases  of  a  mild  type  do  occur  which  soon  give  way  to  ordinary 
routine  treatment,  and  leave  only  a  relatively  small  and  not  very 
opaque,  but  centrally  situated,  corneal  cicatrix,  allowing  of  some 
useful  vision,  which  may  be  improved  by  an  optical  iridectomy. 
Again,  the  prognosis  depends  very  much  upon  the  stage  at  which 
the  case  comes  under  treatment.  The  process  can  frequently  be 
arrested  at  an  early  stage,  while  later  it  will  resist  every  treatment, 
and  will  lead  on  to  panophthalmitis,  or  extensive  leucoma. 

Treatment.— li  the  case  be  not  severe,  atropine,  with  protection 
of  the  eye,  may  cure  in  a  few  days,  but  it  is  not  wise  even  in  the 
apparently  mild  cases  to  trust  to  these  measures.  Warm  fomenta- 
tions should  not  be  used,  as  they  rather  promote  the  activity  of 
the  diseased  process  ;  and  the  eye  should  not  be  bandaged,  lest 
infective  discharge  be  retained  in  the  conjunctival  sac.  Antiseptic 
measures  should  always  be  employed  from  the  beginning,  a  very 
good  one  being  the  thorough,  but  localised,  application  of  pure 
carbolic  acid,  which  can  be  conveniently  applied  with  a  pointed  bit 
of  stick  such  as  a  w^ooden  match  trimmed  to  a  point.  Ethyl  hydro- 
cuprein  exerts  a  specific  action  in  pneumococcal  ulcers ;  it  may  be 
used  in  1  per  cent,  solution  dropped  in  frequently  during  the.  day, 
or  a  small  bit  of  lint  saturated  in  the  solution  may  be  applied  directly 
to  the  ulcerated  surface  for  a  few  minutes.  We  have  also  applied 
the  powder  itself.  The  floor  of  the  ulcer  may  be  washed  with  a 
solution  of  sublimate  1  in  5000,  or  with  hydrogen  peroxide,  or 
other  antiseptic  solutions. 

But  it  is  in  all  respects  wiser  to  deal  with  these  cases,  even  the 
apparently  mild  ones,  actively,  as  soon  as  the  case  comes  under 
observation,  and  in  anticipation  of  the  time,  which  approaches 
rapidly,  w^hen  treatment  cannot  be  of  any  practical  avail.  If,  as  is 
so  often  the  case,  chronic  dacryocystitis  be  present,  the  lacrimal  sac 
should  at  once  be  extirpated  {vide  chap.  xix.).  At  the  same  time 
one  or  other  of  the  following  local  measures  should  be  employed — 
the  first  is  suitable  to  cases  in  which  the  infiltration  is  still  confined 
to  the  superficial  layers,  where  the  products  of  disease  can  all  be 
reached  by  the  cautery ;  while  the  second  is  indicated  in  cases  in 
which  the  deep  parts  of  the  cornea  have  become  involved. 

1.  The  Actual  Cautery  at  a  red  heat  is  a  valuable  method  of 


OHAP.  v.]  THE    CORNEA 


treatment  for  this  ulcer  iji  the  early  stages.  It  is  the  infiltrated 
and  undermined  margin  of  the  ulcer  which  should  be  most  thoroughly 
cauterised  ;  but  its  floor,  if  much  infiltrated,  is  also  to  be  dealt 
with.  The  application  of  fluorescine  just  before  the  use  of  the 
cautery  is  valuable,  as  it  enables  the  operator  to  discern  clearly  the 
whole  of  the  diseased  part  requiring  cauterisation.  Even  the 
cautery  is  often  ineffectual  to  arrest  the  progress  of  the  ulceration. 

At  the  thinnest  part  of  the  floor  of  an  extensive  serpiginous 
ulcer  it  is  desirable  to  make  a  perforation  through  the  cornea  with 
the  point  of  the  cautery  ;  or,  when  the  cauterisation  is  finished, 
the  cornea  may  be  paracentesed  with  a  broad  needle  in  a  sound 
region  beyond  the  ulcer.  The  object  is  to  reduce  the  intra-ocular 
tension,  and  thus  promote  the  nutrition  of  the  cornea.  Of  late 
some  surgeons  have  used  with  advantage,  instead  of  the  cautery, 
hot  air  projected  in  a  stream  on  the  ulcer,  say  with  a  rubber  balloon 
as  used  by  dentists ;  or  the  ulcer  is  touched  with  a  metallic  pointed 
tube  heated  by  hot  air  or  alcohol  vapour  (Wessely). 

Subconjunctival  injections  of  a  1  in  5000  solution  of  cyanide 
of  mercury,  or  of  a  4  per  cent,  saline  solution  assist  the  cure  (p.  120). 

2.  Ssemisch's  Method  consists  in  division  (Keratotomy)  of  the 
ulcer  with  a  Grsefe's  cataract  knife.  Cocaine  having  been  applied, 
the  point  of  the  instrument  is  entered  about  2  mm.  from  the  margin 
of  the  ulcer  in  the  healthy  corneal  tissue,  and,  having  been  passed 
through  the  anterior  chamber  behind  the  ulcer,  the  counter-puncture 
is  made  in  the  healthy  cornea  some  2  mm.  from  the  opposite  margin 
of  the  ulcer.  The  edge  of  the  knife  being  then  turned  forwards, 
the  section  is  slowdy  completed.  The  incision  should  divide  the 
intensely  infiltrated  part  of  the  margin  in  halves.  The  aqueous 
humour  and  hypopyon  are  evacuated,  atropine  is  instilled,  a  bandage 
is  applied,  and  the  patient  soon  gets  relief  from  pain.  Every  day, 
until  healing  of  the  ulcer  is  well  established,  the  wound  must  be 
opened  up  from  end  to  end  with  the  point  of  a  fine  probe  or  spatula, 
the  contents  of  the  anterior  chamber  being  thoroughly  evacuated 
on  each  occasion,  and  atropine  instilled.  The  result  is  that,  in 
many  cases,  the  progress  of  the  ulcer  is  arrested,  and  healing  sets 
in.  The  operation  may  be  employed  with  advantage  even  in  late 
stages  of  the  process. 

Komer  has  proposed,  and  both  he  and  some  others  have  carried 
out  treatment  of  the  serpiginous  ulcer  with  an  anti-pneumococcus 


128  DISEASES   OF    THE   EYE.  [cHAr.  v. 


serum.  The  treatment  is  rational,  but  it  should  be  employed 
early  ;  and  alone  it  is  hardly  sufficiently  rapid  in  its  action  to 
be  relied  upon  in  these  quickly  destructive  cases. 

*  Marginal  Ring  Ulcer  appears  as  a  clean-cut,  or  but  slightly 
infiltrated,  yet  rather  deep,  ulcer  just  inside  the  limbus  of  the  cornea. 
Its  tendency  is  to  extend  along  the  margin  of  the  cornea  ;  and  in 
some  instances  healing  takes  place  in  the  older  parts  of  the  ulcer, 
while  it  is  still  progressive  at  the  newer  parts.  It  may  extend  all 
round  the  cornea,  and  finally  give  rise  to  complete  sloughing  of  the 
latter  by  cutting  off  its  nutrition.  This  ulcer  may  result  in  children 
from  a  marginal  phlyctenular  infiltration,  but  is  more  common  in 
adults,  or  in  aged  people,  whose  nutrition  has  fallen  very  low. 

Treatment. — The  actual  cautery,  silver  nitrate.  If  necessary, 
paracentesis  through  the  ulcer,  eserine  having  been  first  instilled. 
Insufflation  of  xeroform.  Warm  fomentations.  A  dressing  and  ban- 
dage.    Quinine,  iron,  and  strychnine  internally,  with  nutritious  diet. 

Diplobacillus  Ulcer. — This  ulcer,  which  is  not  very  common,  bears 
some  clinical  resemblance  to  the  ulcus  serpens,  and  may  be  mistaken  for 
it ;  but  it  is  associated  with  very  little  pain  or  irritation,  is  less  destructive, 
slower  in  its  progress,  and  more  amenable  to  treatment.  Catarrhal  con- 
junctivitis (p.  55)  is  often  present,  while  dacryocystitis  is  absent.  The 
history  of  a  trauma  is  commonly  to  be  obtained.  The  definite  diagnosis 
can  only  be  made  by  a  bacteriological  examination  of  the  secretion  taken 
from  the  floor  of  the  ulcer,  in  which  the  diplobacillus  (Moiax-Axenfeld) 
(p.  51)  or  the  diplobacillus  liquefaciens  (Petit)  should  be  found.  In  the 
initial  stage,  a  central,  or  almost  central,  grey  infiltration,  often  of  very 
small  size,  appears  near  the  surface  of  the  cornea,  surrounded  by  a  delicate 
halo  of  less  intense  infiltration,  and  there  is  marked  pericorneal  injection. 
After  a  few  days  the  ulcer  becomes  developed.  It  is  2  to  4  mm.  wide, 
shallow,  and  covered  with  a  greyish  membranous  exudation,  which  can  be 
lifted  off.  Occasionally  the  floor  is  greyish-yellow,  and  deep.  The  margin 
is  often  slightly  raised,  and  sometimes  undermined.  The  superficial  layers 
of  the  cornea  around  the  ulcer  are  somewhat  opaque,  with  stippling  of  the 
epithelium  overlying  them  ;  and,  deeper  in  the  cornea,  radiating  grey 
striae  reach  into  the  healthy  cornea,  of.  en  nearly  to  its  margin.  Hypopyon 
is  usually  present.  The  severity  of  the  corneal  process  in  the  later  stages 
often  alters  the  character  of  the  conjunctivitis,  when  any  is  present,  so 
that  it  can  no  longer  be  recognised  as  catarrhal.  Occasionally  small  out- 
lying infiltrations  form  in  the  cornea.  The  ulcer  increases  in  size  by  exten- 
sion of  its  margin  in  all  directions,  although  in  some  cases  this  process, 
as  in  ulcus  serpens,  is  mainly  in  some  one  direction.  Only  in  the  severest 
cases  do  infiltrations  form  in  the  deep  layers  of  the  cornea.  A  neglected 
case  may  lead  to  destruction  of  the  eye  through  panophthalmitis,  but 
careful  treatment  will  save  most  of  these  eyes. 


CHAP,  v.]  THE   CORNEA.  129 

Treatment. — Sulphate  of  zinc  is  practically  a  specific  for  the  ciu-e 
of  these  ulcers.  To  effect  a  satisfactory  result  in  a  severe  case  it  is  neces- 
sary that  the  applications  should  be  made  with  frequency,  regularity,  and 
thoroughness.  A  solution  of  sulphate  of  zinc  of  1  per  cent,  should  be 
dropped  into  the  eye  once  every  hour,  or  even  more  frequently  ;  and  in  the 
intervals  an  ointment  consisting  of  ichthyol  TS  per  cent.,  and  zinc  sulphate 
\  per  cent.,  is  inserted  into  the  conjunctival  sac.  The  ulcer  may  be 
touched  with  a  cotton  wool  pencil  soaked  in  the  solution,  and  compresses 
saturated  with  the  solution  may  be  laid  on  the  eye  at  intervals  for  twenty 
minutes.  The  treatment  is  often  required  to  be  continued  for  two  or  three 
weeks,  or  more.  In  rare  cases  the  galvano-cautery,  or  Ssemisch's  operation 
may  be  needed.  Curetting  is  not  advisable.  The  zinc  treatment  is  in 
no  way  injurious  to  the  eye,  although  temporarily  deposits  of  the  salt  on 
the  ulcer  do  sometimes  occur.  The  opacities  left  by  a  diplobacillus  ulcer 
of  the  cornea  are,  in  time,  capable  of  much  clearing. 

Rodent  Ulcer  (Mooren's  Ulcer). — This  is  a  rare  and  extremely  dangerous 
form  of  ulcer  of  the  cornea,  and  must  not  be  confounded  with  the 
serpiginous  ulcer.     It  is  not  a  purulent  ulcer. 

The  disease  commences  as  a  small — sometimes  even  pinhead  sized — 
grey  infiltration  near  the  corneal  margin,  not  differing  in  appearance  from 
many  a  harmless  catarrhal  infiltration.  This  rapidly  ulcerates.  Other 
similar  infiltrations  appear  in  the  neighbourhood  and  at  other  parts  of  the 
margin,  and  ulcerate,  and  the  ulcers  coalesce  into  one,  of  which  the  advanc- 
ing margin  nearest  the  centre  of  the  cornea  is  undermined.  The  under- 
mined margin,  under  which  a  fuie  probe  can  be  inserted,  consists  of  partially 
necrosed  corneal  tissue,  and  presents  the  appearance  of  a  narrow  whitish 
line  overhanging  the  line  of  active  disease.  The  cornea  beyond  the 
margin  of  the  ulcer  is  normal.  The  eyeball  is  injected.  The  ulcer  does 
not  go  deeper  than  about  one-fourth  of  the  thickness  of  the  cornea,  and 
perforation  seldom  occurs.  Occasionally  a  very  small  hypopyon  is 
present,  and  occasionally  too  there  is  iritis.  There  is  very  great  pain  and 
photophobia  in  some  cases,  and  in  others  hardly  any. 

Before  long  the  ulcer  in  its  oldest  portion  begins  to  be  vascularised 
and  to  heal,  and  finally  leaves  an  intense  cicatrix  behind.  Gradually 
the  ulceration  creeps  round  the  cornea,  and  at  the  same  time  advances 
towards  its  centre,  by  small  infiltrations  appearing  just  inside  the  opaque 
margin,  which  coalesce  and  soon  break  down,  while  healing  is  taking  place 
in  the  oldest  portions  of  the  ulcer.  This  process  goes  on  until,  finally,  the 
whole  siirface  of  the  cornea  has  been  eaten  away,  and  cicatricial  tissue 
substituted  for  it,  its  centre  being  the  last  place  affected,  and  then  vision 
will  have  become  reduced  to  finger-counting  or  \  o  perception  of  light. 

The  progress  of  the  disease  is  very  slow,  many  weeks  or  even  some 
months  often  elapsing  before  the  surface  of  the  whole  cornea  has  been 
destroyed,  and  the  ulceration  may  become  stationary  for  a  time,  only  to 
start  afresh  without  any  apparent  reason.  Some  clearing  up  of  the  cor- 
neal opacity  may  subsequently  take  place,  but  cannot  be  reckoned  upon. 
Yet  in  a  few  cases,  by  gradual  clearing  of  the  cornea,  fairly  good  vision 
has  been  regained  in  the  course  of  a  year  or  two.  The  disease  attacks 
both  eyes  in  about  one-fourth  of  the  cases,  although  there  may  be  an 


130  DISEASES   OF    THE   EYE.  [chap.  v. 


interval  between  the  onset  in  each,  of  weeks,  or  months,  or  more.  It 
attacks  decrepit  people  of  over  middle  life,  but  occurs  also  in  young  persons 
and  in  those  of  apparently  robust  health.  Its  etiology  is  obscure.  No 
specific  micro-organism  has  as  yet  been  discovered  as  the  immediate  cause. 

The  onset  at  the  edge  of  the  cornea  in  the  form  of  small  grey  infiltra- 
tions, the  grey  and  shallow  floor  of  the  ulcer,  its  pale  grey  or  almost  white 
margin,  the  undermining  of  this  margin  (which  may  readily  be  ascertained 
by  passing  the  point  of  a  probe  under  it),  and  the  steady  advance  of  the 
ulceration  towards  the  centre  and  around  the  edge  of  the  cornea,  are  the 
characteristics  of  this  disease. 

Treatment. — Rodent  ulcer  is  usually  a  most  intractable  disease,  no 
reliable  method  of  treatment,  to  which  the  majority  of  cases  will  respond, 
having  been  as  yet  put  forward. 

The  general  nutrition  of  the  individual  is  to  be  improved,  but  reliance 
is  mainly  to  be  placed  on  local  treatment,  which  should  especially  be 
directed  to  the  undermined  margin,  or  rather  to  the  surface  immediately 
underlying  this,  after  the  overhanging  lip  has  l:een  cut  away  with  fine 
sharp  scissors. 

The  galvano-cautery  is  much  in  use  here,  and  it  is  important  that 
the  burning  should  be  rather  deep.  Pure  liquid  carbolic  acid  applied 
with  a  fine  bit  of  wood,  the  excess  being  taken  up  with  a  bit  of  blotting 
paper,  is  also  useful.  In  a  case  under  our  care  absolute  alcohol 
applied  to  the  ulcer  (p.  134)  produced  a  remarkable  and  rapid  ciire,  so 
that  a  small  central  area  of  sound  cornea  was  preserved  ;  and  a  second 
case  has  been  similarly  cured.  Curetting,  tinctiare  of  iodine  applied  with 
a  camel's-hair  pencil,  sublimate  lotion,  with  a  bandage  and  the  usual  warm 
fomentations,  may  help  in  the  treatment.  The  covering  of  the  diseased 
part — after  it  has  been  well  cauterised — or  of  the  entire  cornea,  with  a 
conjunctival  flap,  is  worth  the  trial. 

Keratomalacia  (Infantile  Ulceration  of  ths  Cornea  with  Xe  osis  of  the 
Conjunctiva)  is  a  very  rare  affection.  It  attacks  some  poorly  nourished 
children  early  in  the  first  year  of  life,  making  its  appearance  at  or  near 
the  centre  of  the  cornea.  Iritis  always  supervenes  in  severe  cases.  That 
portion  of  the  bulbar  conjunctiva  which  is  exposed  in  the  palpebral  aper- 
ture at  either  side  of  the  cornea  undergoes  slight  epithelial  xerosis,  similar 
to  that  in  functional  night  blindness,  due  to  retinal  exhaustion.  Some- 
times the  xerosis  of  the  conjunctiva  is  absent.  Ulceration  of  the  cornea 
soon  comes  on,  tlirough  necrosis  of  the  layers  lying  over  an  interstitial 
infiltration  ;  and  this  ulceration  spreads  until  it  involves  the  whole  of  the 
cornea,  except  a  very  narrow  margin.  Finally,  perforation,  with  prolapse 
of  the  iris,  and  panophthalmitis  may  supervene.  The  accompanying 
symptoms,  ciliary  congestion,  photophobia,  etc.,  are,  strange  to  say,  very 
slightly  marked. 

Both  eyes  become  affected  as  a  rule,  altliough  the  disease  usually 
attacks  one  eye  some  time  before  its  fellow.  The  patients  almost  always 
die  of  diarrhoea,  pneumonia,  etc. 

Cause. — Streptococci  have  been  found  in  the  corneal  ulcer  and  in  the 
conjunctiva,  while  a  general  streptococcus  invasion  of  the  vascular  system 
of  the  whole  body  is  also  present.     To  the  latter  circumstance  are  referred 


CHAP,  v.]  THE   CORNEA.  131 


the  conditions  which  lead  to  a  fatal  termination  ;  but  in  some  cases  the 
pneumococcus  alone  was  found.  Many  of  the  infants  attacked  are  syphi- 
litic, and  spirochaete  have  been  found  in  the  cornea  (Stephenson),  but 
whether,  as  is  held  by  some,  the  corneal  process  is  a  specific  one,  and  not 
merely  part  of  the  general  cachexia,  is  an  open  question. 

Treatment  is  generally  of  little  avail ;  but  warm  fomentations,  the 
use  of  non-irritating  antiseptic  lotions,  and  the  usual  treatment  for  puru- 
lent affections  of  the  cornea  should  be  tried.  Such  means  as  may  possibly 
promote  improvement  of  the  general  system  are  obviously  called  for,  and 
in  cases  of  congenital  syphilis,  calomel  internally  or  mercurial  inunctions. 

Neuro-ParalytiC  Keratitis. — In  paralysis  of  the  Ophthalmic  Division  of 
the  Fifth  Nerve  purulent  infiltration  and  ulceration  of  the  cornea  with 
hypopyon  are  occasionally  observed,  or  the  process  inay  be  very  superficial 
and  aseptic.  It  was  formerly  believed  that  the  fifth  nerve  had  an  influence 
over  the  nutrition  of  the  cornea,  and  hence  that  neuro-paralytic  keratitis 
is  a  trophic  process  ;  but  an  analysis  of  the  recorded  cases  shows  that  the 
keratitis  occurs  only  in' irritative  lesions  of  the  fifth  nerve,  and  that  the 
development  of  the  affection  is  assisted  by  the  diminished  reflex  lid-action 
and  secretion  of  tears,  and  consequent  drying  and  disorganisation  of  the 
corneal  epithelium,  which  renders  it  possible  even  for  septic  infection  of 
the  cornea  to  take  place.  This  disease,  therefore,  cannot  be  regarded  as 
of  neuropathic  origin  in  the  strict  sense  of  the  term. 

That  keratitis  is  not  very  common  with  paralysis  of  the  fifth  nerve  is 
doubtless  due  to  the  moisture  of  the  surface  of  the  cornea  being  sufficiently 
maintained  through  the  consensual  action  of  the  eyelids  of  the  affected  eye 
with  those  of  the  opposite  eye  ;  and,  also,  that  reflex  lacrimation  of  the 
affected  eye,  although  in  diminished  degree,  results  from  stimulation  of 
the  opposite  cornea.  Yet  under  certain  conditions — e.g.  if  the  nictitation 
be  incomplete  (partial  paralysis  of  the  facial  nerve),  or  if  there  be  some 
proptosis — the  cornea  may  become  dry,  and  keratitis  may  appear.  In  all 
the  cases  published  of  paralysis  of  both  fifth  nerves,  keratitis  appeared, 
for  here  the  protection  of  the  reflexes  originating  on  the  other  side  was  not 
present.  The  absence  of  any  ill-result  to  the  cornea  from  the  operation  of 
extirpation  of  the  gasserian  ganglion  on  one  side  only  for  severe  neuralgia 
is  explained  by  what  has  just  been  stated. 

The  surface  of  the  anaesthetic  cornea  becomes  dull  over  a  central  cloudy 
area,  and  this  is  soon  followed  by  a  superficial  erosion.  The  ulcer  may 
become  purulent,  and  may  end  in  panophthalmitis,  or  it  may  heal  up, 
leaving  a  central  opacity.  In  some  cases  the  eye  becomes  soft  and  more 
or  less  shrunken. 

The  commonest  causes  of  neuro-paralytic  keratitis  are  intra-cranial 
tumours  and  fractures  of  the  skull. 

Treatment  consists,  in  the  milder  cases,  in  protection  of  the  cornea  by 
keeping  the  eyelids  closed  with  a  bandage,  or  by  fastening  them  together 
with  a  dermic  suture.  The  severer  cases  of  purulent  infiltration  or  ulcera- 
tion must,  in  addition,  be  dealt  with  on  the  lines  laid  down  in  previous 
pages  for  the  treatment  of  those  conditions. 

Herpes  Corneae  Febrilis.— Not  only  in  herpes  zoster  ophthalmicus 


132  DISEASES   OF    THE   EYE.  [chap.  V. 


(chap,  xviii.),  but  also  in  herpes  febrilis  (or  catarrhalis)  is  a  vesicular 
eruption  liable  to  occur  on  the  cornea.  It  is  met  with  in  any  of  the 
inflammatory  affections  of  the  respiratory  tract,  from  a  common  cold 
to  severe  pneumonia,  and  may  be  associated  with  herpetic  eruptions 
on  the  lips.  It  also  occurs  with  whooping  cough,  and  with  inter- 
mittent and  typhoid  fever  ;  but  it  may  be  a  primary  affection. 
It  is  probably  more  common  than  ophthalmic  practice  would  lead  us 
to  think,  for  it  is  the  resulting  ulceration  which  usually  comes  under 
our  notice.  The  patient  complains  of  the  sensation  of  a  foreign 
body  in  the  eye,  with  lacrimation  and  photophobia,  and  these 
symptoms  disappear  w^hen  the  vesicles  rupture. 

On  the  surface  of  the  cornea  of  one  eye  is  formed  a  grouj)  of 
clear  vesicles,  each  from  0*5  to  1*0  mm.  in  diameter.  They  usually 
form  in  a  line,  which  runs  obliquely  across  the  cornea,  or  sometimes 
in  a  vertical  direction.  Now  and  then  they  are  arranged  in  trefoil 
shape  or  in  a  circle.  The  covering  of  the  vesicles  is  short-lived, 
and,  as  already  remarked,  the  resulting  ulcer  is  that  which  the 
surgeon  usually  first  sees.  Even  it,  however,  is  thoroughly 
characteristic.  On  the  surface  of  the  clear  cornea  is  an  irregular 
loss  of  epithelium,  along  the  margins  of  which  may  still  sometimes 
be  seen  the  shreds  of  the  late  covering  of  the  vesicle.  The  margin 
of  the  region  which  is  bared  of  its  epithelium  is  dentated,  and  can 
only  be  mistaken  for  a  traumatic  loss  of  epithelium.  But  the  latter 
would  not  present  the  peculiar  '  string-of-beads '  appearance. 
The  floor  of  the  loss  of  substance  is  formed  by  the  superficial  layers 
of  the  cornea,  and  ansesthesia  of  the  cornea  is  confined  to  this  place, 
and  does  not,  as  in  herpes  zoster,  extend  to  the  rest  of  the  cornea. 
The  tension  of  the  eye  is  generally  reduced.  Under  favourable 
circumstances  this  loss  of  epithelium  may  be  rapidly  repaired  ; 
although  even  then  more  slowly  than  one  of  equal  dimensions,  but 
of  traumatic  origin.  Usually  the  healing  process  is  slow.  >Some- 
times  more  or  less  intense  opacities  form  in  the  area  and  at  the 
margin  of  the  ulcer,  with  hypopyon,  iritis,  etc.,  and  the  loss  of 
substance  becomes  deep,  with  a  dentated  margin.  This  unfavourable 
course  is  the  result  of  secondary  infection  of  the  ulcer. 

Treatment  at  an  early  stage,  before  the  vesicles  have  burst  or 
the  loss  of  substance  has  become  infiltrated,  consists  in  protection 
of  the  eye,  and,  when  infiltration  has  set  in,  in  disinfection,  with 
protection.     In  obstinate  cases  4  per  cent,  saline  subconjunctival 


CHAP.    V. 


THE   CORNEA.  133 


injections  are  often  of  use.  If  the  vesicles  give  great  pain  they  may 
be  ruptured  by  dusting  a  little  calomel  into  the  eye,  or  by  brushing 
it  with  a  camel' s-hair  pencil  wet  with  sterile  saline  solution  after 
which  a  well-fitting  antiseptic  dressing  is  applied.  Cocaine  should 
be  used  as  sparingly  as  possible,  ow4ng  to  its  ill-effect  on  the  epithe- 
lium when  used  in  excess.  Atropine  and  warm  fomentations  are 
indicated,  and  a  weak  yellow  oxide  ointment  is  of  use  in  some  cases. 
Where  the  nostrils  are  affected,  weak  sublimate  or  other  antiseptic 
and  alkaline  washes  should  be  applied. 

Dendriform  (SeVSpov,  a  tree)  Keratitis. — This  is  not  a  very  un- 
common affection.  It  takes  the  form  of  a  superficial  and  chronic 
ulceration,  with  but  little  infiltration  of  its  margins  or  floor,  and 
presents  the  appearance  of  a  fine  groove,  or  grooves,  on  the  cornea. 
It  spreads  chiefly  over  the  central  region  of  the  cornea  by  throwing 
out  branches  on  either  side,  while  on  the  end  of  each  branch  there 
is  usually  a  minute  grey  infiltration,  and  its  true  nature  may  easily 
be  overlooked  unless  the  cornea  be  examined  by  the  combined  focal 
method.  Pain  and  irritation  are  sometimes  severe,  and  again  but 
slight  or  absent.  Some  slight  permanent  opacity  may  remain 
when  cure  has  been  effected. 

Fig.  58  represents  three  of  the  most  common  forms  of  the  disease. 
At  a,  in  the  drawing  on  the  left,  there  is  a  nebula  where  healing  has 
set  in,  while  in  another  part  of  the  same  cornea  the  process  is  in  an 


^- 


Fig.  58. 

active  stage.  In  the  central  drawing,  near  the  upper  corneal 
margin,  there  is  a  fine  herpetic-like  eruption,  and  a  long  groove 
passing  down  from  it.  And,  in  the  drawing  on  the  right,  the 
tendency  to  branch  is  well  shown. 

In  cases  which  have  been  long  neglected,   and  in   which  the 


34  DISEASES   OF    THE   EYE.  [chap,  v. 


disease  has  run  riot  over  the  cornea,  no  healing  process  having  set 
in,  the  surface  becomes  dull  grey  and  irregular,  as  though  ploughed 
up,  the  primary  characteristic  appearances  being  lost  by  reason  of 
the  amount  of  disease  present.  The  ulceration  rarely  becomes 
septic.  Some  patients  never  have  more  than  a  single  attack,  while 
in  others  several  recurrences,  sometimes  at  intervals  of  one  or  more 
years,  may  take  place,  aud  in  such  cases  iritis  is  liable  to  occur. 

The  Cause  has  not  been  definitely  ascertained.  The  opinion  is 
strongly  held  by  some,  that  these  ulcers  result  from  a  herpetic 
eruption  on  the  cornea,  and  they  certainly  occur  under  the  same 
conditions  as  herpes. 

Treatment. — Curetting  with  a  sharp  spoon,  with  the  subsequent 
application  of  1  in  1000  solution  of  corrosive  sublimate  to  the 
cornea,  is  recommended  by  some,  also  the  application  of  pure  car- 
bolic acid  to  the  ulcer  with  a  finely  pointed  wooden  match,  care 
being  taken  to  confine  it  to  the  ulcer.  The  actual  cautery  is  some- 
times useful.     But  these  remedies  often  fail  to  produce  a  cure. 

Absolute  alcohol  has  proved  in  our  hands  an  almost  certain, 
as  well  as  a  rapid,  cure.  A  bit  of  matchwood  is  sharpened  to  a  fairly 
fine  point,  and  around  the  latter  a  little  cotton  wool  is  rolled  not  very 
thickly.  This  is  moistened  with  absolute  alcohol,  and  the  ulcer  is 
then  rubbed  with  the  point  with  such  pressure  as  to  take  away  the 
epithelium,  and,  so  far  as  possible,  the  rest  of  the  corneal  surface  is 
avoided.  Immediately  afterwards  the  conjunctival  sac  is  freely 
washed  out  with  sterilised  salt  solution,  to  remove  all  surplus 
alcohol,  which  would  increase  the  subsequent  pain.  The  application 
is  painful  even  with  cocaine.  As  a  rule  there  is  pain  for  some  hours 
afterwards,  and  for  this  hot  fomentations  afford  the  best  relief  ; 
cocaine  is  of  little  use.  Usually  one  application  is  sufficient  to  pro- 
duce cure,  but  some  cases  require  it  to  be  repeated  after  four  or  five 
days.  It  is  not  desirable  to  repeat  the  application  more  than  once  or 
at  most  twice,  as  the  corneal  epithelium  is  then  liable  to  become  de- 
ranged, and  filamentary  and  bullous  keratitis  may  be  produced.  Pure 
carbolic  acid  acts  as  well,  and  has  the  advantage  over  alcohol,  in  that 
its  action  can  be  more  easily  limited  and  that  it  is  much  less  painful. 

The  application  of  a  fine  point  of  sulphate  of  copper  to  the 
ulceration  also  produces  some  good  cures.  It  is  less  painful  than 
the  alcohol,  because  its  action  is  easily  confined  to  the  ulcerated 
part,  but  it  is  not  so  certain  in  its  action. 


CHAP,  v.]  THE    CORNEA.  135 

Bullous  Keratitis. — Bullae  very  rarely  form  on  the  cornea.  They  are 
seldom  the  primary  condition,  but  usually  depend  on  a  diseased  process 
in  the  true  cornea.  This  process  may  itself  be  a  primary  disease  ;  but 
more  commonly  it,  too,  is  secondary  to  deep  changes  in  the  eye,  such  as 
absolute  glaucoma,  iridocyclitis,  etc.  Very  rarely  bullae  are  seen  on  the 
cornea  of  an  otherwise  sound  eye,  in  a  person  whose  health  is  in  a  debili- 
tated state.  Bullae  on  the  cornea  are  sometimes  caused  by  blows  on  the 
eye,  or  by  direct  traumata  of  the  cornea.  The  formation  of  a  bulla  is 
attended  by  much  pain  and  photophobia,  which  disappear  as  soon  as  the 
bulla  ruptures.  One,  or  more  than  one,  bulla  may  form  at  a  time.  After 
a  day  or  two  the  bulla  rviptures,  and  its  walls  hang  in  shreds  from  the 
surface  of  the  cornea,  and  may  produce  the  appearance  of  filamentary 
keratitis,  and  the  seat  of  the  bulla  presents  shallow  depressions.  These 
losses  of  substance  heal  without  leaving  any  permanent  opacity.  After 
an  interval  of  days  or  weeks  another  crop  of  bullae  appears,  and  runs  the 
same  course. 

Treatment. — The  bulla?  should  be  opened,  and  their  walls  snipj)ed 
away  with  a  scissors,  and  a  bandage  applied.  The  recurrent  attacks 
may  cease  after  a  length  of  time  ;  but,  if  it  be  a  secondary  affection,  treat- 
ment can  influence  it  only  by  relieving  the  process  in  the  cornea  which 
gives  rise  to  it.  If  it  be  a  primary  process,  w^arm  fomentations,  atropine, 
and  a  bandage,  with  remedies  directed  to  the  correction  of  any  fault  in 
the  general  state  of  the  health  which  may  exist,  are  suitable. 

Filamentary  Keratitis. — This  is  very  rare.  Its  name  is  due  to  the 
fine  threads,  like  twisted  spun-glass,  several  of  which  hang  from  the  sur- 
face of  the  cornea,  and  give  the  condition  its  characteristic  appearance. 
These  threads  never  reach  a  length  of  more  than  3  or  4  mm.,  and  are 
composed  of  twisted  proliferating  epithelial  cells,  each  thread  ending  in 
a  bulbous  enlargement  caused  by  degeneration  of  the  epithelium.  The 
condition  may  result  from  a  superficial  trauma  of  the  cornea,  or  from  a 
bullous  or  herpetic  keratitis,  also  after  several  applications  of  absolute 
alcohol,  when  used  for  dendritic  keratitis. 

Treattnent. — The  instillation  of  a  3  per  cent,  solution  of  chloride  of 
ammonium  into  the  eye  every  two  hours,  by  which  the  exfoliation  of  the 
epithelial  growth  is  promoted  and  hastened,  produces  a  rapid  cure.  Pro- 
tection of  the  eye  with  a  dressing  and  bandage  is  important. 

Keratitis  Aspergillina. — This  rare  disease  was  described  by  Leber.  The 
appearance  presented  is  that  of  an  ulcer  from  3  to  5  mm.  in  diameter, 
occupying  a  rather  central  position  in  the  cornea.  The  surface  of  the 
ulcer  is  of  a  greyish  or  whitish  yellow,  and  is  very  irregular.  A  striking 
and  characteristic  appearance  is  the  dryness  of  this  surface,  the  copious 
discharge  of  tears  flowing  over  it  without  seeming  to  wet  it.  The  rest 
of  the  cornea  is  slightly  opaque  and  dull,  and  there  is  a  small  hypopyon 
present.  The  conjunctiva  is  injected  and  swollen,  and  is  covered  with 
some  mucovis  secretion.  The  eyelids  are  rather  swollen.  There  is  photo- 
phobia and  often  severe  pain.  Masses  removed  from  the  surface  of  the 
ulcer  and  examined  with  the  microscope  are  found  to  be  full  of  the 
aspergillus  fumigatus.  It  may  usually  be  ascertained  that  an  injury  has 
preceded  the  appearance  of  the  ulcer. 


13G  DISEASES    OF    THE   EYE.  [chap. 


Treatment. — The  membranous  mass  which  forms  the  floor  of  the 
ulcer  should  be  peeled  off,  and  the  underlying  surface  cauterised  and 
dressed  with  xeroform,  after  which  a  good  and  rapid  cure  takes  place. 
Hot  fomentations  should  not  be  used,  as  they  promote  the  growth  of  the 
fungus. 

Tubercular  Ulceration  of  the  Cornea.    See  p.  143. 


{h)  Non-Ulceeative  Inflammations  of  the  Cornea. 

Abscess. — This  affection  is  on  the  borderland  between  the 
ulcerative  and  non-ulcerative.  inflammations  of  the  cornea  ;  for  in 
one  case  it  results  in  an  ulcer — usually  the  ulcus  serpens — while 
again  it  runs  its  course  "without  ulceration.  The  abscesses  which 
are  seated  in  the  more  superficial  layers  are  those  which  go  on  to 
ulceration  ;    those  in  the  deeper  layers  are  less  likely  to  do  so. 

Abscess  differs  from  infiltration  in  that  the  pus  which  forms  it 
destroys  the  true  corneal  tissue — the  fibrillae  and  fixed  corpuscles — 
and  does  not  merely  lie  between  them. 

Signs  and  Symptoms. — The  appearance  presented  is  that  of  a 
yellowish  circumscribed  opacity,  more  intense  at  its  margin  than 
at  its  centre,  seated  at  or  near  the  middle  of  the  cornea, 
and  surrounded  by  a  light  grey  zone.  It  is  usually  round  in  shape, 
but  when  situated  near  the  edge  of  the  cornea  it  is  apt  to  be 
crescentic.  The  surface  of  the  cornea  just  over  the  abscess  is  at 
first  a  little  elevated  over  the  general  surface,  but  later  on  becomes 
flattened,  owing  to  a  falling-in  of  the  normal  layers  anterior  to 
the  abscess  ;  and  the  epithelium  of  the  flattened  part  has  a  dull, 
breathed-on  look.  The  rest  of  the  cornea  may  also  lose  its  brilliancy, 
although  in  a  much  less  degree.  Hypopyon  and  iritis  are  constant 
attendants  upon  corneal  abscess.  There  is  much  injection  of  the 
conjunctival  and  ciliary  blood-vessels.  Severe  pain  in  and  about 
the  eye,  and  blepharospasm,  are  common ;  yet  occasionally  a 
corneal  abscess  is  attended  by  but  little  pain  or  other  irritation. 

Progress. — The  abscess  spreads  through  the  cornea,  usually 
advancing  at  the  side  where  the  opacity  is  most  intense.  Before 
long,  if  the  abscess  be  superficial,  it  may  become  converted  into  an 
ulcer,  and  may  result  in  an  ulcus  serpens,  already  described  (p.  124). 
The  deeper  abscesses  spread  through  the  cornea  more  or  less  widely, 
and  ultimately  become  absorbed,  without  having  caused  ulceration. 


CHAP,  v.]  THE    CORNEA.  137 

But  even  these  abscesses  leave  considerable  opacity  behind.  The 
process  which  ends  in  ulceration  is  the  more  common  of  the  two. 

Etiology. — Abscess  is  the  result  of  infection  of  the  cornea  with 
pyogenic  organisms,  which  reach  it  either  from  without,  through 
some  traumatic  loss  of  substance  of  the  corneal  epithelium,  or 
from  within,  by  the  agency  of  the  blood.  The  micro-organisms, 
which  are  introduced  through  a  superficial  loss  of  substance,  may 
either  have  been  on  the  foreign  body  which  produced  the  injury, 
or  they  may  have  been  present  in  the  conjunctival  sac,  or  in  the 
lacrimal  sac.  Infection  through  the  blood  is  occasionally  seen  in 
some  acute  exanthematous  diseases,  such  as  scarlatina,  measles, 
and  smallpox  ;  more  especially  in  the  latter  in  its  convalescent 
stage. 

Treatment. — Atropine,  warm  fomentations,  and  a  dressing.  But 
if  these  mild  measures  do  not  in  a  day  or  so  arrest  the  progress  of 
the  abscess,  the  same  treatment  must  be  adopted  as  for  purulent 
ulcers,  and  resort  must  be  had  either  to  the  actual  cautery  or  to 
Ssemisch's  operation   (p.   127). 

Ring  Abscess. — This  is  a  purulent  circular  infiltration  of  the  cornea 
lying  a  few  inillimetres  inside  the  actual  margin,  and  it  usually  becomes 
converted  into  a  ring  ulcer.  The  conjunctiva  is  chemotic,  and  from  it 
there  is  a  greenish  yellow  discharge.  It  is  not  a  common  affection,  and  is 
caused  by  metastasis  and  perforating  wounds,  including  operation  wounds, 
at  any  part  of  the  cornea,  and  sometimes  follows  on  perforating  wounds  of 
the  sclerotic.  It  may  also  occur  after  spontaneous  perforation  of  a  corneal 
ulcer,  or  from  the  infection  of  an  old  incarcerated  iris  prolapse.  Its  pro- 
gress is  extremely  rapid,  leading  to  complete  necrosis  of  the  cornea  and 
to  panophthalmitis  within  a  few  days  after  the  perforating  injury  is  sus- 
tained, and  often  rendering  excision  or  evisceration  necessary  almost  as 
soon  as  the  case  comes  under  observation.  In  some  cases,  especially  in 
those  of  metastatic  origin,  the  infiltration  inay  disappear  without  loss  of 
substance,  while  in  others  it  may  be  possible  to  save  some  sight,  or  at 
least  the  shape  of  the  eyeball.  The  micro-organism  concerned  is  the 
bacillus  pyocyaneus,  which  produces  virulent  toxine  in  large  quantity. 

Treatment. — Ssemisch's  operation.  Atropine,  and  careful  cleansing 
of  the  floor  of  the  ulcer  and  conjunctival  sac  with  perchloride  of  mercury 
solution  1  in  2500.  Subconjunctival  injections  of  mercury  oxycyanate 
(1—5000). 

Syphilitic  Diseases  of  the  Cornea.  Disuse  Interstitial  or  Paren- 
chymatous Keratitis. — This  is  by  far  the  most  common,  and  best 
known,  of  the  syphilitic  affections  of  the  cornea.  A  very  similar 
disease  is  caused  by  tubercle  (p.  143).     The  syphilitic  form  is  most 


138  DISEASES   OF   THE   EYE.  [chap.  v. 

frequently  met  with  between  the  ages  of  five  and  fifteen.  It  usually 
commences  at  one  part  of  the  margin  as  a  light  greyish  opacity, 
accompanied  by  slight  injection  of  the  ciliary  vessels.  The  rest 
of  the  corneal  margin  soon  becomes  similarly  affected  ;  and  the 
opacity  then  gradually  extends  concentrically  into  the  cornea. 
In  this  way  the  whole  cornea  becomes  affected  by  degrees  ;  and 
its  epithelium  acquires  a  breathed-on  or  ground-glass  appearance. 
Occasionally  the  opacity  commences  at  the  centre,  and  not  at  the 
margin  of  the  cornea,  often  in  the  form  of  small  grey  spots,  and 
extends  towards  the  margin,  which  it  may  not  reach  before  clearing 
commences. 

The  opacity  lies  in  the  deep  layers  of  the  true  cornea,  and  is 
slightly  more  intense  here  and  there.  It  may  be  only  a  very  light 
cloud,  or  the  cornea  may  be  so  opaque  as  to  render  the  iris  quite 
invisible.  Along  with  the  opacity,  vessels  form  in  the  deeper  layers 
of  the  cornea,  but  the  degree  of  vascularisation  varies  much  in 
different  cases.  In  some  the  presence  of  vessels  can  only  be  ascer- 
tained by  careful  examination  with  a  high  convex  glass  (+  16-0) 
behind  the  ophthalmoscope,  or  with  the  corneal  microscope  ;  while 
in  others  the  new  vessels  are  present  in  great  numbers,  and  can 
be  readily  seen  with  the  naked  eye.  In  other  cases  close  leashes 
of  vessels  near  the  anterior  surface  of  the  cornea  follow  the  opacity, 
giving  rise  to  the  appearance  known  as  the  '  salmon  patch.'  The 
infinite  variety  in  the  degree  of  opacity  and  in  the  amount  and 
arrangement  of  the  vascularisation,  results  in  great  variation  in 
the  appearances  in  different  cases. 

When  the  whole  cornea  has  become  opaque,  it  begins  to  clear 
at  the  margin,  and  the  central  portion  becomes  even  more  opaque 
than  the  margin  had  ever  been.  The  clear  margin  gradually  in- 
creases in  width,  until  only  a  rather  intense  central  opacity  is  left. 
This  central  opacity  slowly  breaks  up,  and  becomes  absorbed,  but 
not  always  completely  ;  and  then  considerable  and  permanent  im- 
pairment of  vision  may  remain.  Even  in  the  more  peripheral  por- 
tions of  the  cornea,  in  some  cases,  a  faint  maculated  cloudiness  may 
be  found  on  careful  examination,  years  after  the  active  process  has 
ceased. 

In  severe  cases,  iritis  and  chorioiditis  are  nearly  always  present, 
although  the  latter  is  not  observable  until  the  cornea  has  become 
clear  enough  to  admit  of  an  ophthalmoscopic  examination.     Strictly 


CHAP,  v.]  THE    COBNEA.  139 

speaking,  indeed,  it  should  be  regarded  as  a  disease  of  the  uveal 
tract,  to  which  the  posterior  layers  of  the  cornea  belong. 

The  two  forms  above  described,  one  commencing  at  the  margin, 
the  other  at  the  centre  of  the  cornea,  and  more  or  less  vascularised, 
but  for  the  most  part  ultimately  occupying  the  entire  cornea,  are 
those  we  are  wont  to  find  in  children  and  young  adults.  But  in 
older  persons,  up  to  thirty  or  thirty-five,  milder  forms  of  interstitial 
keratitis  are  met  with.  These  rarely  occupy  more  than  a  small 
region  of  the  cornea,  generally  towards  its  centre,  either  as  a  patch 
or  as  a  ring  of  opacity,  and  with  little  or  no  vascularisation. 

The  affection  is  often  accompanied  by  a  good  deal  of  pain  and 
blepharospasm,  especially  in  the  severe  vascular  forms,  and  there, 
too,  the  tension  of  the  eye  is  apt  to  be  temporarily  reduced  ;  but 
again  attacks  of  increased  tension  may  occur,  which  in  a  few  cases 
may  lead  to  Buphthalmos. 

The  acute  stage  of  the  disease  lasts  from  six  to  eight  weeks,  or 
longer.  But  the  entire  process  may  not  be  completed  for  many 
months,  or  even  a  year.     Relapses  sometimes  occur. 

In  children  both  eyes  invariably  become  affected,  although  not 
always  at  the  same  time,  the  onset  in  the  second  eye  beginning 
often  when  the  inflammation  in  the  first  eye  has  made  some 
progress,  or,  perhaps,  when  the  first  eye  has  undergone  cure. 
It  is  important,  in  the  very  commencement  of  treatment,  to  ac- 
quaint the  patient  or  his  parents  with  the  likelihood  of  this  course 
of  events. 

In  adults  usually  one  eye  alone  is  attacked,  iritis  is  rare,  the 
duration  of  the  process  is  comparatively  short,  and  complete  clearing 
up  is  relatively  frequent.  The  opacity  is  due  to  a  round-celled  in- 
filtration of  the  deeper  layers  of  the  cornea,  associated  sometimes 
with  epithelioid  and  giant  cells. 

Causes. — The  affection  is  more  common  in  girls  than  in  boys, 
and  most  frequently  appears  during  second  dentition,  when  the 
upper  incisors  are  being  cut,  or  at  puberty. 

It  depends  upon  some  serious  derangement  of  the  general 
nutrition  ;  and  this,  in  about  70  per  cent,  of  the  cases,  is  inherited 
syphilis — a  fact  which  was  first  pointed  out  by  8ir  Jonathan  Hutchin- 
son. The  children  are  often  thin,  anaemic,  and  of  stunted  growth, 
with  flat  nose,  cicatrices  at  the  angles  of  the  mouth,  and  are  fre- 
quently  more   or   less   deaf  ;     and   the   peculiarities   of  the   incisor 


140  DISEASES   OF    THE   EYE.  [chap.  v. 

teeth,  so  well  known  from  Hutchinson's  description,  are  present  in 
about  one-half  of  the  cases.  The  presence  of  the  spirochsete  pallida 
in  the  cornea  has  been  demonstrated  microscopically. 

Occurring  in  adults,  the  affection  is  rarely  due  to  inherited 
syphilis,  although  acquired  lues  may  sometimes  be  taken  as  its 
cause  ;  while,  again,  it  will  often  be  impossible  to  assign  any  origin 
for  it  other  than  the  universal  one  of  exposure  to  cold,  etc.  Some 
cases  are  due  to  tubercular  disease  (p.  143).  While  in  some  syphilis 
and  tubercle  are  combined  and  the  cases  react  both  to  Wassermann's 
and  to  the  tuberculin  tests. 

Prognosis. — In  children — in  view  of  the  possibility  of  an  incom- 
plete clearing  of  the  cornea,  as  well  as  of  the  serious  uveal  com- 
plications liable  to  supervene,  and  which  may  completely  annihilate 
vision — the  prognosis  must  be  guarded,  although  by  no  means 
hopeless,  in  those  cases  where  the  opacity  is  very  intense,  or  where 
there  is  much  vascularity.  Yet,  in  the  milder  cases,  a  favourable 
prognosis  may  be  given.     The  affection  recurs  but  very  rarely. 

In  adults,  as  stated,  the  prognosis  is  much  more  favourable. 

Treatment. — In  the  early  stages  no  irritants  should  be  applied 
locally.  Atropine  is  important  for  the  prevention  of  iritis  or  of 
posterior  synechiae  ;  and  the  use  of  radiant  heat,  in  the  form  of 
hot  poultices  or  fomentations,  or  the  Japanese  warmer,  pr-omotes 
the  nutrition  of  the  cornea  and  hastens  the  cure  by  absorption  of 
the  cellular  elements  which  form  the  opacity.  Dionine  is  often  very 
useful.  A  dressing  and  bandage  should  be  worn.  Subconjunctival 
injections  of  the  oxycyanide  of  mercury  1  in  5000,  are  often  useful. 
When  the  acute  stage  is  ended,  dionine  and  the  yellow  oxide  ointment 
may  be  employed  with  benefit  for  stimulating  the  absorbents  to 
carry  of!  what  remains  of  the  opacity.  Massage  may  be  used  with 
advantage  in  both  stages  to  disperse  the  infiltration.  In  severe 
cases  a  course  of  mercurial  inunctions,  continued  for  several  weeks, 
is  very  advisable  ;  care  being  taken  not  to  allow  stomatitis  to 
exceed  moderate  bounds.  Salvarsan  does  not  seem  to  act  more 
rapidly  in  the  cure  of  interstitial  keratitis  due  to  congenital  syphilis 
than  does  an  active  mercurial  treatment,  but  a  few  very  good  results 
have  been  obtained  by  it.  In  mild  cases  a  tonic  plan  of  treatment, 
with  iodide  of  iron  and  cod-liver  oil,  is  the  most  suitable. 

Counter-irritation,  in  the  form  of  blisters  to  the  temple  or  a 
seton   in   the   scalp,    is   extensively   employed   by   some   surgeons. 


cHAt.  V.I  THE   CORNEA.  141 


We  do  not  use  this  treatment,  as  we  doubt  its  value,  and  are  loth 
to  add  to  the  worries  inseparable  from  so  wearisome  a  disease. 

The  following  much  rarer  forms  of  syphilitic  disease  of  the 
cornea  are  described  : — 

Sfecific  Punctiform  Interstitial  Keratitis. — Circumscribed,  pin- 
head-sized,  .greyish  infiltrations  form  at  various  levels  in  the 
otherwise  clear  stroma  of  the  true  cornea.  They  do  not  grow 
larger,  nor  suppurate.  They  form  rapidly,  and  disappear  rapidly 
when  cure  commences,  leaving  little  or  no  opacity  behind.  The 
affection  is  not  associated  with  iritis,  but  there  is  usually  some 
ciliary  injection.  In  somewhat  similar  cases  the  punctiform  opacities 
are  not  so  defined,  but  are  surrounded  by  a  halo  of  lighter  opacity, 
and  iritis  is  present.  This  affection  is  a  manifestation  of  tertiary 
syphilis,  and  the  punctiform  opacities  have  been  regarded  as  the 
products  of  a  gummatous  inflammation.  The  treatment  would  be 
iodide  of  potash  internally,  and  locally  atropine,  warm  fomentations, 
and  a  bandage. 

Gumma  of  the  Cornea. — Some  cases  of  true  gumma  of  the  cornea  have 
been  recorded.  The  growth  appears  as  a  pale  grey  or  whitish  elevation, 
more  or  less  vascularised,  on  the  cornea.  The  diagnosis  depends  very 
much  on  the  patient  being  the  subject  of  tertiary  syphilis.  The  treatment 
is  iodide  of  potash,  salvarsan,  or  mercury. 

Keratomalacia  is  also  reckoned  by  some  to  be  a  syphilitic  affection 
(p.   13C). 


Fig.  59. — Xodular  Keratitis.     Mr.  W.  J.  Hancock's  case.      Trs.  0.  S.  xxv. 

Guttata  or  Nodular  Keratitis,  and  Grating-like  or  Reticular  Keratitis  (Fig. 
59). — Nodular  or  reticular  keratitis — a  satisfactory  title  is  wanting — is  a 
rare  disease.  Its  presence  is  apt  to  be  overlooked  in  the  early  stages  ; 
for  by  focal  illumination  the  cornea  may  seem  perfectly  normal,  and  the 
rest  of  the  eye,  excejDt  perhaps  for  some  slight  distension  of  the  anterior 
ciliary  and  larger  conjunctival  vessels,  is  healthy,  and  the  eye  is  free  from 
irritation.  Ophthalmoscopic  examination  shows  a  number  of  small  opaque 
patches  of  all  shapes,  occupying  the  most  central  portion  of  the  cornea, 
while    between    them,    and    sometimes   reaching    out   more   towards   the 


142  DISEASES   OF    THE   EYE.  [cHAr.  V. 


periphery,  innumerable  very  fine  dots  are  present — nodular  keratitis.  In 
some  cases  the  opaque  patches  are  absent,  while  a  number  of  fine  forked 
lines  are  seen  in  the  early  stage  outside  the  central  region,  which  at  first  is 
occupied  by  fine  dots  alone.  At  a  later  period,  the  arrangement  of  the 
radiating  forked  lines  assumes  a  somewhat  reticulated  appearance,  like 
that  of  a  grating,  and  Ihey  extend  to  the  centre  of  the  cornea — reticular 
or  grating-like  keratitis.  The  corneal  microscope  shows  that  these  dots, 
patches,  and  lines  are  greyish,  and  situated  close  under  the  epithelium. 
The  surface  of  the  latter  is,  in  the  early  period,  in  no  way  altered. 

Gradually  the  diseased  appearances  increase  in  amount,  the  anterior 
ciliary  vessels  become  more  distended,  vision  sinks  lower,  and  the  patient 
may  sometimes  complain  of  slight  pain,  with  lacrimation,  and  swelling 
of  the  eyelids  ;  but  more  commonly  there  is  no  irritation.  The  lines,  dots, 
and  iDatches  now  begin  to  show  slight  elevations  on  the  cornea,  although 
covered  by  epithelium.  At  a  still  later  period  the  opacity  in  the  centre  of 
the  cornea  becomes  more  intense,  a  marginal  zone  of  the  cornea  remaining 
fairly  clear.  At  this  stage  the  diagnosis  may  again  become  doubtful,  owing 
to  the  amount  of  the  disease  which  obscures  the  characteristic  appearance 

Both  eyes  are  always  affected,  either  simultaneously,  or  with  a  short 
interval.  The  disease  is  exceedingly  intractable  and  chronic,  lasting  inany 
years,  and  finally  causing  much  loss  of  sight.  Most  of  the  cases  observed 
have  been  in  young  adult  males,  and  it  often  attacks  more  than  one  member 
of  a  family,  in  one  or  in  succeeding  generations — it  is,  in  fact,  one  of  the 
family  diseases.  It  begins  between  the  tenth  and  thirteenth  year.  No 
relation  to  syphilis  or  other  constitutional  disease  has  been  made  out. 
It  seems  to  be  a  degenerative  affection. 

Treatment. — Treatment,  so  far,  has  proved  of  little,  if  any,  benefit. 
Yellow  oxide  of  mercury  ointment,  warm  fomentations,  galvanism,  and 
chloral  hydrate  eye-drops  have  been  used.  Dionine  and  subconjunctival 
injections  should  also  be  given  a  trial. 


Fig.  60. — Forms  of  Discoid  Keratitis.     (After  Schirmer.) 

Discoid,  or  Annular,  Keratitis  (Keratitis  Disciformis  of  Fuchs)  (Fig.  60). 
— This  disease  occurs  for  the  inost  part  in  persons  of  middle  age,  and  fre- 
quently commences  with  slight  defects  of  the  epithelium  caused  by  traumata 
or  by  herpes.  It  has  also  been  seen  by  Schirmer  in  coiuiection  with  vaccine 
vesicles  on  the  eyelids  or  conjunctiva.  It  is  characterised  by  a  delicate 
grey  disc,  which  is  situated  deeply  in  the  true  cornea,  at  or  near  its  central 
region,  and  which  is  marked  off  sharply  all  round  from  the  normal  peripheral 
portion  of  the  cornea  by  a  more  intensely  narrow  grey  margin  or  ring  ;  or, 
outside  this  ring,  there  may  be  another  or  even  two  more  peripheral  rings, 
concentric  with  each  other.     Witli  the  corneal  microscope  grey  striae  can 


CHAr.  v.]  THE   CORNEA.  143 

sometimes  be  seen  in  the  opacity  which  may  radiate  out  into  the  clear 
cornea,  parallel  with  each  other  or  crossing  at  various  angles,  similar  to 
those  which  occur  in  some  other  keratitidos.  The  surface  of  the  affected 
region  is  dull  and  its  sensation  diminished.  In  the  course  of  the  malady, 
wliich  may  run  over  several  months,  slight  superficial  ulcerations  occur, 
and  finally  a  rather  intense  opacity  is  left  at  the  seat  of  the  disease.  The 
uveal  tract  is  not  usually  imphcated,  but  in  rare  instances  the  presence  of 
some  punctate  deposits  may  be  detected.  Occasionally  glaucoma  sets  in. 
Treatment  is  of  little  avail.  It  should  consist  in  atropine,  bandage, 
hot  fomentations,  sub-conjunctival  saline  injections,  and  dionine. 

Tubercular  Keratitis. — Tubercular  disease  of  the  cornea  presents 
itself  in  several  forms  : — 

1.  Pale  yellow  nodules  which  appear  at  the  corneal  margin, 
extend  to  its  deep,  but  not  to  its  deepest,  layers,  and  protrude, 
slightly  over  its  surface,  accompanied  by  ciliary  injection.  These 
nodules  advance  towards  the  centre  of  the  cornea,  become  confluent, 
and  finally  undergo  absorption,  leaving  an  intense  opacity  behind  ; 
or  they  may  break  down  into  ulceration,  which  may  occupy  the 
greater  part  of  the  corneal  surface.  The  ulcer  never  perforates, 
and  after  a  time  healing  takes  place  with  cicatricial  opacity,  which 
may  clear  up  to  a  great  extent.  This  is  the  only  truly  primary 
form  of  tubercular  disease  of  the  cornea,  no  other  part  of  the  eye 
being  affected,  and  it  is  rare.  In  the  other  forms  of  tubercular  cor- 
neal disease  the  process  is  propagated  to  it  from  neighbouring  parts. 

2.  Diffuse  interstitial  (or  parenchymatous)  keratitis.  In  about 
70  per  cent,  of  the  cases  of  this  affection,  syphilis,  congenital  or 
accjuired,  is  recognised  as  its  cause  (p.  137).  It  is  held  that  of  the 
30  per  cent,  wdiich  remain  most,  if  not  all,  of  the  caries  depend  on 
tubercle,  but  without  the  presence  in  the  cornea  of  tubercular 
nodules.  Tubercular  disease  of  the  anterior  uveal  tract  (chap,  vii.) 
co-exists  ;  and,  presumably,  the  corneal  affection  is  the  effect  of 
toxines  diffused  in  the  cornea  from  the  angle  of  the  anterior  chamber. 
This  form  is  capable  of  complete  retrocession. 

3.  Greyish  sclerotising  opacities  caused  by  tubercular  nodules, 
which  grow  into  the  corneal  margin  in  its  deepest  layers  from  the 
ligamentum  pectinatum.  These  opacities  occur  at  several  parts 
of  the  periphery  of  the  cornea  ;  and,  by  throwing  forward  tongues, 
they  slowly  spread  into  the  cornea.  Although  the  process  may 
cease  at  any  point,  the  cornea  remains  very  opaque  at  the  parts 
attacked,  with  resulting  disfigurement  or  loss  of  sight. 


144  DISEASES   OF   THE   EYE.  [chap.  v. 


4.  Miliary  tubercular  nodules  may  form  in  the  cornea  in  con- 
nection with  tubercular  episcleritis  at  the  corresponding  portion 
of  the  corneal  margin,  and  may  spread  further  into  the  cornea. 
These  nodules  do  not  ulcerate,  and  ultimately  they  disappear,  leav- 
ing opacity  behind. 

Secondary  pannus,  ulcers,  and  granulations,  may  follow  tubercle 
of  the  conjunctiva.  The  ulcers  sometimes  perforate.  In  the  scrap- 
ings from  tubercular  ulcers  the  tubercle  bacillus  may  be  found. 

Treatment. — For  tubercular  ulceration,  curetting,  with  the 
insufflation  of  xeroform,  or,  should  these  fail,  the  cautery.  For 
the  other  forms  a  course  of  tuberculin  is  indicated  (chap.  vii.). 

Keratitis  Punctata. — The  term  keratitis  punctata  was  originally 
used  to  denote  the  condition  associated  with  irido-cyclitis  and 
sympathetic  ophthalmia,  which  consists  in  the  deposit  of  lymph 
in  the  form  of  fine  dots  on  the  back  of  the  cornea,  derived  from 
inflamed  portions  of  the  uveal  tract,  mainly  from  the  ciliary  pro- 
cesses. But  for  this  condition  the  term  'punctate  deposits'  is  to 
be  preferred  to  keratitis  punctata.     (Chap,  vii.) 

Fuchs  has  described  a  form  of  keratitis  which  he  terms  Keratitis 
punctata  super ficialis ,  and  which  has  a  good  claim  to  that  name.  It 
begins  with  the  symptoms  of  an  acute  conjunctivitis,  but  there  is  decided 
pericorneal  injection,  while  the  conjunctiva  is  not  much  injected,  nor  is  the 
discharge  mucous  or  purulent,  but  is  rather  an  abundant  lacrimal  secretion. 
There  is  j)hotophobia  and  pain.  Either  at  the  same  tiine,  or  some  days 
or  weeks  afterwards,  minute  grey  spots  may  be  seen  in  the  most  superficial 
layers  of  the  cornea,  the  epithelium  over  the  spots  being  somewhat  raised 
up,  giving  a  dull  appearance  to  the  corneal  smface.  The  spots  are  often 
arranged  in  groups  or  rows,  and  may  be  scattered  over  nearly  the  entire 
cornea,  or  else  confined  to  its  central  region.  There  may  be  but  a  few  of 
them,  or  there  may  be  a  hundred  or  more,  and  one  or  both  eyes  may  be 
affected.  The  initial  irritative  symptoms  soon  disappear  ;  but  the  spots 
themselves  remain  for  many  weeks,  or  even  months,  and  finally  fade  away 
completely.  The  disease  is  more  common  in  young  people  than  in  later 
life,  and  occurs  usually  in  connection  with  a  catarrh  of  the  air  passages  ; 
but  it  must  not,  by  reason  of  this,  be  confounded  with  herpes  of  the  cornea. 
The  spots  are  often  very  faint,  and  hence  can  easily  be  overlooked,  unless 
searched  for  with  the  combined  focal  method.  In  this  country  the  affec- 
tion is  rather  rare,  but  several  cases  of  it  have  come  under  our  notice. 

The  Treatment  should  consist  in  atropine,  dressing  and  bandage,  yellow 
oxide  of  mercury  ointment,  massage,  and  warm  fomentations.  To  hasten 
the  cure,  in  some  long-drawn-out  cases,  removal  of  the  corneal  epithelium, 
which  is  to  a  great  extent  the  seat  of  the  disease,  has  been  recommended. 

Sclerotising   Opacity    of    the    cornea    sometimes    complicates 


CHAP,  v.l  THE   CORNEA.  14i 


scleritis,  or  disease  of  the  ciliary  body  (Syphilis,  Tubercle).  It 
affects  the  margin  of  the  cornea  in  the  neighbourhood  of  the  scleral 
affection,  but  not  extending  more  than  2  to  3  mm.  into  the  cornea, 
except  in  very  severe  cases.  It  is  an  intense  white  opacity  situated 
in  the  true  cornea  (Plate  II.  Fig.  5),  and  is  apt  to  remain  as  a  per- 
manent opacity,  even  when  the  scleritis  undergoes  cure.  In  such 
cases  of  sclero-keratitis  iritis  is  often  present. 

Treatment. — If  the  inflammation  has  subsided  the  opacity  can 
no  longer  be  cured.  For  the  acute  stage  see  treatment  of 
scleritis. 

Ribandlike  Keratitis  (Transverse  Calcareous  Film  of  the  Cornea  ; 
Calcareous  Film  of  the  Cornea). — This  is  a  degenerative  alteration 
of  the  cornea  w^hich  occurs  chiefly  in  eyes  destroyed  by  severe  intra- 
ocular processes,  such  as  irido-cyclitis,  sympathetic  ophthalmitis, 
glaucoma,  etc. 

It  also  occasionally  occurs  as  a  primary  disease  in  some  persons 
of  advanced  life.  In  these  latter  instances  glaucoma  often  comes 
on  at  a  later  period,  or  the  corneal  disease  may  be  followed  by 
irido-cyclitis,  or  central  chorioiditis.  It  seems  probable  that, 
in  these  primary  cases,  the  cause  of  the  degeneration  is  simply  a 
loss  of  vital  energy  in  the  corneal  tissue,  due,  it  may  be,  to  vascular 
changes. 

The  disease  occupies  that  transverse  strip  of  the  cornea  which 
is  uncovered  in  the  commissure  of  the  eyelids  during  waking.  It 
usually  commences  on  the  inner  margin  of  the  cornea,  but  soon 
appears  at  the  outer  margin,  and  advances  from  each  direction 
towards  the  centre,  where  the  two  sections  join.  It  presents  the 
appearance  of  a  greyish  opacity,  sometimes  with  a  brownish  tinge. 
In  most  cases,  white  calcareous  deposits  are  present  in  and  under  the 
epithelium.  In  blind  eyes  which  are  constantly  rolled  upwards,  the 
opacity  is  found,  not  in  the  central  transverse  section  of  the  cornea, 
but  in  the  exposed  lower  third.  The  opaque  masses  consist  of  car- 
bonate and  phosphate  of  lime.  Leber  puts  forward  the  view  that 
an  abnormally  abundant  supply  of  phosphate  of  lime  in  the  blood, 
and  nutritive  fluid  of  the  cornea,  is  the  cause  of  this  condition,  the 
rapid  evaporation  on  the  exposed  part  of  the  cornea  being  the  reason 
why  the  deposit  takes  place  there.  The  deposit  is  at  first  in  Bow- 
man's membrane,  but  later  on  it  may  appear  in  the  anterior  layer  of 
the  true  cornea,  and  in  the  epithelium. 
10 


146 


DISEASES    OF    THE   EYE. 


[chap.  v. 


Treatment. — Some  improvement  may  be  effected  by  scraping 
away  the  chalky  deposit. 

Superficial  Epithelial  Dystrophy  of  the  Cornea. — This  is  a  degenerative 
affection  of  the  cornea  which  occurs  in  old  people,  especially  in  women. 
It  is  characterised  by  a  superficial  central  cloudiness  over  which  the 
epithelium  is  dull  and  uneven.  Small  vesicles  appear,  and  also  clear  spots 
or  pits,  in  the  opaque  area.  The  cornea  becomes  insensitive.  The  disease 
sjDreads  as  years  go  on,  and  treatment  is  of  no  avail.  A  somewhat  similar 
appearance  occurs  after  removal  of  the  thyroid  gland,  in  myxoedema,  and 
at  times  also  in  old  cases  of  glaucoma. 


ECTASIES    OF   THE    CoRXEA. 

Staphyloma  of  the  Cornea,  except  in  the  very  rare  cases  in 
which  it  is  congenital,  is  the  result  of  a  perforating  ulcer  of  the  cornea, 
and  the  methods  for  obviating  its  occurrence  have  been  set  forth 
at  p.  121. 

The  ulcer,  having  healed,  may  present  a  w^eak  cicatrix,  which 
becomes  bulged  forwards  by  even  the  normal  intra-ocular  tension. 

If  the  iris  be  not  incarcerated  in 
this  cicatrix  the  anterior  chamber 
will  be  made  deeper.  But  staphy- 
loma cornese,  in  which  the  iris  is 
incarcerated,  is  the  more  common 
condition.  When  a  corneal  ulcer 
is  large,  a  correspondingly  large 
portion  of  iris  is  liable  to  become 
prolapsed  into  it,  and  to  form  a 
bulging  mass.  This  may  burst  and 
collapse,  and  a  flat  cicatrix  may  be 
formed  ;  or,  if  it  do  not  rupture, 
it  may  form  what  is  termed  a 
partial  staphyloma  of  the  cornea 
and  iris,  the  latter  becoming  con- 
solidated by  the  formation  of  a  layer  of  connective  tissue  over 
it  (Fig.  61). 

If  the  whole,  or  a  very  large  part,  of  the  cornea  be  destroyed 
by  an  ulcer,  the  iris  is  completely  exposed.  It  soon  begins  to  be 
covered  with  a  layer  of  lymph,  which  gradually  becomes  converted 
into  an  opaque  cicatricial  membrane.  Should  this  not  be  strong, 
the  normal  intra-ocular  tension  is  sufficient  after  a  time  to  make  it 


Fig.  61. — Almost  total  staphy- 
loma of  cornea,  with  great  thick- 
ening of  its  cicatricial  tissue. 


CHAP,  v.]  THE    CORNEA.  147 

bulge  ;  or,  increased  iiitra-ocular  tension  may  arise  in  consequence  of 
further  changes  within  the  eye,  and  then  bulging  of  the  pseudo- 
cornea  all  the  more  surely  comes  on,  and  the  condition  is  termed 
total  staphyloma  of  the  cornea,  although  obviously  the  term  is 
somewhat  strained,  as  in  fact  there  is  no  cornea.  Such  a  staphy- 
lomatous  cornea  is  intensely  white,  and  would  correctly  be  called 
a  leucomatous  staphyloma.  Sometimes  a  total  staphyloma  has  a 
lobulated  appearance,  owing  to  the  pseudo-cornea  having  some  of 
its  fibres  stronger  than  others  ;  and  hence  the  name  given  to  the 
condition  (from  o-ra^vXt],  a  hunch  of  grapes),  and  which  has  in  time 
become  applicable  to  almost  any  bulging  of  the  cornea  or  sclerotic. 
Such  staphylomata  are  apt  to  increase  gradually  to  a  very  large  size. 

Treatment. — In  cases  of  partial  staphyloma,  where  a  clear  portion 
of  the  cornea  remains,  an  iridectomy  is  frequently  indicated  for 
the  reduction  of  the  tension — so  that  further  bulging  may  be  arrested 
— as  well  as  for  the  sake  of  the  artificial  pupil,  which  may  improve 
sight,  in  cases  where  the  normal  pupil  is  obliterated  by  corneal 
opacity.  If  the  tension  becomes  raised  again  after  iridectomy,  a 
trephine  operation  may  be  done  (see  chap.  ix.). 

When,  sight  having  been  lost,  the  staphyloma  is  very  pro- 
minent, or  when  total  staphyloma  is  present,  enucleation  of 
the  eye-ball,  or  one  of  the  following  operative  measures,  must  be 
adoped. 

Abscission. — A  cataract  knife  being  passed  through  the  base 
of  the  staphyloma,  with  its  edge  directed  upwards,  the  upper  two- 
thirds  of  the  staphyloma  are  separated  off,  while  the  remaining 
third  is  detached  by  means  of  scissors.  If  the  lens  be  present  it 
must  now  be  removed.  The  wide  opening  becomes  filled  up  with 
granulations,  and  becomes  cicatrised,  or  the  opening  is  closed  with 
conjunctival  sutures. 

The  foregoing  and  other  methods  of  abscission  are  only  applicable 
where  the  tension  is  either  low  or  normal.  If  it  be  high,  the  liability 
to  intra-ocular  haemorrhage  during  the  operation  makes  enucleation, 
evisceration,  or  Mules'  operation  more  suitable  proceedings.  Indeed, 
probably  most  surgeons  would  now  employ  one  of  the  two  latter 
operations  in  all  these  cases. 

Evisceration  was  proposed  to  obviate  meningitis  after  the  removal 
of  suppurating  globes,  and  also  to  take  the  place  of  enucleation  in 
cases   of   sympathetic   ophthalmitis.     Practically   all   surgeons   are 


[48  DISEASES   OF   THE  EYE.  [chap.  v. 


now  opposed  to  its  employment  in  the  latter  cases,  but  for  staphy- 
loma of  the  cornea  it  is  not  open  to  objection. 

The  cornea  is  removed  by  making  an  incision  with  a  Gra3fe's 
knife,  so  as  to  include  one  half  of  the  corneo-scleral  margin,  and  by 
completing  the  circumcision  with  scissors.  All  the  contents  of  the 
globe  are  then  evacuated  by  means  of  Mules'  scoop,  care  being  taken 
to  remove  the  chorioid  unbroken  by  carefully  peeling  it  from  the 
sclerotic  margin  backwards,  until  it  is  only  held  at  the  lamina  cribrosa. 
The  scoop  is  then  used  to  lift  out  the  separated  unbroken  chorioid 
and  the  other  contents  of  the  globe. 

Finally,  the  margins  of  the  sclero-conjunctival  wound  are  drawn 
together  with  a  few  points  of  suture.  The  whole  proceeding  should 
be  done  with  strict  aseptic  precautions,  chief  among  which  is  the 
free  use  of  irrigation  with  a  1  in  5000  solution  of  corrosive  sublimate 
before,  during,  and  after  the  operation,  the  interior  of  the  globe 
being  most  carefully  washed  out  w^ith  the  solution  in  a  full  stream. 
The  result  is  a  fairly  good  and  freely  movable  stump  for  the  applica-* 
tion  of  an  artificial  eve. 


Mules'  Operation. — This  proceeding — a  modification  of  the  foregoing — 
was  also  proposed  by  Mules  for  cases  of  threatened  sympathetic  ophthal- 
mitis, and,  like  simple  evisceration,  has  not  met  with  universal  accejatance 
in  those  cases,  because  it  is  held  not  to  afford  sufficient  protection  against 
sympathetic  ophthalmitis.  In  cases  of  staphyloma,  however,  and  in  some 
other  conditions  where  the  questions  of  sympathetic  ophthalmitis,  or  of 
a  new  growth  in  the  eye  to  be  operated  on,  do  not  enter  into  consideration, 
no  proceeding  is  more  satisfactory,  at  least  in  young  persons,  than  this 
beautifvil  one  of  Mules'.  Its  object  is  to  provide  a  still  better  stump  for 
the  artificial  eye  by  the  insertion  into  the  scleral  cavity  of  a  hollow  glass 
sphere,  and  the  prothesis  it  provides  is  almost  perfect.  It  is  performed  as 
follows  : — 

The  cornea  is  removed — the  conjunctiva  having  first  been  freed  from 
the  scleral  edge  towards  the  equator  of  the  eyeball — and  the  contents  of 
the  eyeball  evacuated,  as  in  simple  evisceration.  The  opening  is  now 
enlarged  vertically,  to  admit  of  the  introduction  of  one  of  the  glass  spheres. 
This  introduction  is  best  effected  by  means  of  a  special  instrument  designed 
for  the  purpose  by  Mules.  The  spheres  are  made  in  several  sizes  to  suit 
different  cases,  and  it  is  not  desirable  to  use  the  largest  which  will  fit  into 
any  given  eye.  The  sphere  having  been  inserted,  the  margins  of  the  sclerotic 
opening  are  united  vertically  by  some  points  of  interrupted  suture,  for 
which  purpose  silk  or  hemp  is  preferable  to  catgut,  as  the  latter  is  apt  to 
undergo  absorption  before  complete  union  has  taken  place.  The  conjunc- 
tival opening  is  then  closed  by  another  set  of  sutiues  placed  at  right  angles 
to  the  sclerotic  line  of  closure.      Similar  aseptic  precautions  ai'e  requu'ed, 


CHAP,    v.] 


THE   CORNEA. 


49 


as  in  simple  evisceration,  and  all  bleeding  should  have  ceased  in  the  cavity 
before  the  glass  sphere  is  inserted.  Before  the  lids  are  closed  the  anterior 
surface  of  the  globe  is  well  covered  with  boric  acid  or  xeroform.  A  firm 
bandage  is  applied.  The  eye  is  not  dressed  for  forty-eight  hours,  and 
subsequently  once  every  twenty-four  hours,  using  the  sublimate  solu- 
tion freely.  There  is  generally  some  reaction,  consisting  of  chemosis, 
swelling  of  the  eyelids,  and  pain,  and  sometimes  these  symptoms  are 
very  marked,  especially  if  too  large  a  sphere  have  been  employed.  In  the 
course  of  a  week  or  so  this  all  passes  off,  and  a  very  perfect  stump  is 
obtained. 

We  have  only  once  seen  a  glass  sphere  broken  by  a  blow  after  a  Mules' 
operation.  Various  substances  have  been  utilised  to  replace  the  glass 
ball,  gold,  silver,  bone,  etc.,  and  they  have  also  been  introduced  into  the 
Capsule  of  Tenon  after  enucleation. 

With  a  well-fitting  glass  eye,  the  cosmetic  result  of  the  Mules'  operation 
is  infmitely  better  than  that  produced  either  by  excision  or  by  evisceration 
of  the  eyeball.  It  is  more  uniformly  successful  in  young  people  than  at 
more  advanced  ages,  and  therefore  it  is  better  not  to  use  it  in  persons  over 
twenty-five.  To  ensure  success  it  is  an  important  point  that  the  glass 
globe  be  not  too  large — it  should  be  an  easy  fit  for  the  cavity  of  the  sclerotic. 
In  case  the  sutures  give  way,  and  the  sclerotic  opening  gapes,  an  attempt 
may  be  made  to  reclose  it  with  new  sutures,  but  this  is  not  often  successful. 
As  a  rule  the  glass  globe  must  in  that  event  be  removed,  and  the  case  then 
becomes  one  of  simple  evisceration. 

Komoto's  operation  is  a  very  good  and  simple  one,  for  large  and  especially 
thin  staphylomata.  The  cornea  is  transfixed  horizontally,  with  the  edge 
of  the  knife  forwards  and  the  wounds  at  the  points  of  transfixion  enlarged. 
The  knife  is  then  withdrawn,  the  staphyloma  is  seized  on  each  side  with 
forceps  by  an  assistant,  and  the  section  completed  with  scissors  (Fig.  62  A,). 
A  suture  (c)  is  then  introduced  at  the  apex  of  the  triangular  incision   the 


a. 


a\ 

\ 

V 

1 

^^^~~~~.^Jy>^. 

\ 

A 

C. 

^^J 

h. 

/\ 

A 

% 

V 

B 

Fig.  62. 

Fig. 

63. 

Fig.  64. 


two  lateral  portions  of  the  staphyloma  are  trimmed,  and  two  other  sutures 
applied  at  a  and  h  (Fig.  63  B). 

Another  useful  method  (Attias')  is  shown  in  Fig.  64.     The  staphyloma 
is  transfixed  and  divided  horizontally  (D  to  E).     Sutures  are  now  passed, 


[50  DISEASES    OF    THE   EYE.  [chap.  v. 


before  any  further  incision  is  made,  from  a  to  a  and  6  to  6  ;  with  a  fine 
scissors,  one  blade  being  introduced  into  the  first  incision,  triangular  flaps 
are  cut  out,  avoiding  of  course  the  sutures.  The  effect  may  be  diminished 
by  removing  only  three  triangular  flaps. 

We  have  been  doing  this  operation  for  some  years,  but  without  sutures, 
and  it  is  astonishing  how  the  flaps  come  together  after  a  time,  even  though 
they  may  not  lie  in  apposition  when  made. 

In  most  cases  it  is  as  well  to  remove  the  lens,  and  if  necessary  some  of 
the  iris.  When  introducing  sutures  into  the  cornea  it  is  better  when 
possible  not  to  pass  them  through  the  whole  thickness,  but  only  through 
the  anterior  layers. 


Conical  Cornea,  or  Keratoconus,  is  a  cone-shaped  protrusion  of 
the  cornea  occurring  in  an  otherwise  healthy  eye  (Fig.  65),  The 
cornea  remains  clear,  except  sometimes  just 
at  the  apex  of  the  cone,  where  a  slight 
nebula  may  be  present.  The  position  of 
the  apex  is  usually  not  quite  central,  and  is 
then  most  commonly  either  in  the  lower 
outer,  or  lower  inner  quadrant  of  the  pupil. 
If  the  apex  be  touched  with  a  probe  its 
extreme  thinness  may  be  ascertained.  The  condition  is  easy  of 
diagnosis  in  its  advanced  stages  by  mere  inspection  of  the  cornea, 
especially  in  profile.  When  seen  from  the  front  it  gives  the  e5^es 
of  the  patient  a  peculiar  glistening  appearance. 

In  the  early  stages,  when  the  light  is  thrown  on  the  cornea  from 
the  ophthalmoscope  mirror,  the  corneal  reflex  will  be  noticed  to  be 
smaller  at  the  centre,  owing  to  the  greater  curvature  there,  and 
a  dark  shadow,  circular  or  crescentic  in  shape  according  to  the 
incidence  of  the  light,  appears  between  the  margin  and  the  centre 
of  the  cornea.  The  ophthalmoscopic  image  of  the  fundus  and  the 
corneal  images  as  seen  with  the  astigmometer  appear  distorted. 

In  some  extreme  cases  the  patient  observes  a  pulsating  altera- 
tion in  the  size  of  the  objects  looked  at.  This  is  due  to  the  pulsation 
of  the  apex  of  the  cone,  imparted  to  it  by  the  intra-ocular  circulation, 
and  is  comparable  to  the  pulsation  of  an  unclosed  fontanelle  of  the 
skull.  Objectively  the  pulsation  can  be  seen  M^th  the  corneal 
microscope  and  with  Schiotz's  tonometer  (see  chap.  ix.).  Sensation 
at  the  apex  of  the  cone  is  often  diminished.  A  brownish  ring  (due 
to  the  deposit  of  haemosiderin)  has  been  observed  in  the  cornea  in 
some  cases. 


CHAP,  v.]  THE    CORNEA.  151 


On  examination  with  the  keratoscope  the  corneal  reflex,  instead 
of  being  normal,   as  at  A  (Fig.  66),  is  altered  as  at  B   or  C. 

With  the  astigmometer,  the  portions  of  the  images  on  the  apex 
are  smaller  and  overlap,  while  the  more  peripheral  portions  may 
only  touch,  or  may  even  not  come  into  contact. 

The  process  begins  in  early  adult  life,  progresses  slowly,  never 
leads  to  rupture  or  ulceration  of  the  cornea,  and,  finally,  after  many 
years,  ceases  to  progress,  but  does  not  undergo  cure.  Both  eyes  are 
apt  to  become  attacked,  one  after  the  other.  The  disturbance  of 
vision  is  very  great,  owing  to  the  extreme  irregular  astigmatism 
produced. 

Etiology. — There  is  very  little  doubt  that  this  disease  is  due  to 


^p         ^» 


ABC 

Fig.  66. — A,  reflected  image  of  Keratoscope  on  normal  cornea.  B,  reflected 
image  at  apex  of  cone  in  conical  cornea.  C,  Reflected  image  slightly 
eccentric  in  conical  cornea. 

some  form  of  malnutrition.  The  individuals  affected  are  generally 
delicate,  and  almost  always  both  eyes  are  affected.  In  some  cases 
the  thyroid  has  been  found  enlarged  and,  associated  with  it,  a 
trophic  disturbance  of  the  skin  and  nails.  Increased  lympho- 
cytosis has  also  been  noted  by  some,  but  others  deny  that  it  is  a 
frequent  occurrence  in  cases  of  conical  cornea  and  believe  that  it  has 
no  direct  connection  with  this  disease. 

Treatment. — Optical. — {a)  Correction  of  the  refraction  in  the  early 
stages  or  in  slight  cases.  A  moderate  improvement  in  vision  may 
be  obtained  by  high  concave  or  even  convex  cylinders,  alone  or  com- 
bined with  concave  sphericals.  (b)  Temporary  removal  of  the 
irregular  refraction  by  the  use  of  '  contact '  glasses.  But  these 
are  not  very  practical. 

Reduction  of  tension. — Treatment  by  pilocarpine  or  eserine  and 
bandaging  do  not  produce  much  effect,  neither  do  iridectomy  or 
trephining  alone  effect  a  cure  in  most  cases. 

Excision  of  a  portion  of  corneal  tissue  by  means  of  a  trephine 
(Bowman)  or  with  a  Grsefe  knife  (Morton)  has  sometimes  given  good 


152  DISEASES   OF    THE   EYE.  [chap.  v. 

results,  but  they  have  the  disadvantage  of  leaving  the  cornea  as 
weak  as  before. 

Cautery. — This  is  the  method  which  is  almost  universally  relied 
upon  at  present.  The  object  of  it  is  to  remove  the  conical  distension 
by  the  contraction  which  follows  the  burn,  and  at  the  same  time 
to  strengthen  the  cornea  by  the  formation  of  a  firm  cicatrix. 

The  electro-  or  thermo-cautery  is  applied  to  the  apex  of  the  cone, 
or  to  one  side  of  it,  and  a  small  circular  area  burnt  deeply  ;  some 
surgeons  perforate  the  cornea,  others  do  not,  being  afraid  of  the 
possible  dangers  attendant  on  the  presence  of  a  fistula  of  the  cornea 
which  may  remain  open  for  several  weeks.  Glaucoma  has  occurred 
in  some  cases.  We  have  frequently  perforated  the  cornea  and 
have  never  had  any  bad  result,  and  the  effect  is  certainly  greater 
than  in  the  cases  in  which  the  anterior  chamber  has  not  been  opened. 

Sir  Anderson  Crichett  lays  much  stress  on  the  graduated  appli- 
cation of  the  cautery.  He  first  applies  the  cautery  at  a  black  heat 
to  the  whole  area  intended  to  be  cicatrised ;  within  this  area  a  little 
more  is  destroyed  at  a  slightly  increased  heat,  while  the  very  apex 
is  touched  with  a  cautery  at  a  dull  red  heat.     One  sitting  is  sufficient. 

Cauterisation  without  perforation  may  also  be  combined  with 
paracentesis  of  the  cornea,  and  the  anterior  chamber  can  be  evacu- 
ated daily  for  a  week  ;  or  the  effect  of  the  cautery  may  be  increased 
by  trephining  at  the  sclero-corneal  margin  (chap.  ix.). 

With  the  object  of  increasing  the  solidity  of  the  scar  it  has  been 
recommended  to  cauterise  not  only  the  apex  of  the  cone,  but  also  to 
extend  the  area  of  cauterisation  over  a  triangular  portion  of  the 
cornea  with  its  base  at  the  limbus  in  order  to  encourage  the  growth 
of  vessels  into  the  scar,  or  a  conjunctival  flap  can  be  drawn  over  the 
burnt  surface. 

After  the  cicatrisation  following  on  cauterisation  is  completed, 
the  scar  may  be  tattooed,  and  an  optical  iridectomy  will  usually  be 
required,  especially  if  the  cone  has  been  quite  central.  The  cases 
in  which  the  apex  of  the  cone  has  an  eccentric  position  are  those  most 
benefited  by  cauterisation,  because  the  resulting  scar  interferes  less 
with  vision  than  where  it  is  central. 

Atrophic  Degeneration  of  the  Margin  of  the  Cornea  (Marginal  Groove 
of  the  Cornea,  Marginal  Ectasy  of  the  Cornea). — This  rare  disease  occurs 
mostly  in  persons  of  advanced  life,  and  is  always  associated  with  an  arcus 
senilis.     It  is  at  first  a  shallow  groove  situated  either  immediately  outside 


CHAP,  v.]  THE   CORNEA.  153 

the  arcus — that  is,  between  it  and  the  margin  of  the  cornea — or  on  the 
arcus,  or  immediately  inside  the  latter.  The  inner  margin  of  the  groove 
is  steep,  while  its  outer,  or  peripheral  margin  passes  gradually  to  the  level 
of  the  cornea.  In  its  early  stages  the  floor  of  the  groove  is  slightly,  and  its 
inner  margin  more  markedly,  nebulous,  but  at  a  later  period  it  becomes 
quite  pellucid.  So  that,  if  it  occupy  the  arcus,  the  latter  may  disappear  ; 
and  at  no  time  is  there  any  disturbance  of  the  epithelium  covering  the 
groove.  Fine  vessels  often  extend  into  the  groove  from  the  conjunctiva. 
The  groove  usually  commences  in  the  upper  margin  of  the  cornea,  and 
sometimes  extends  around  the  whole  margin.  In  the  course  of  time — it 
may  be  some  years — the  thin  floor  of  the  groove  is  pressed  forwards  by 
the  normal  intra-ocular  tension,  and  a  pellucid  bulging,  or  ectasy,  takes 
the  place  of  the  groove.  Disturbance  of  vision  is  not  complained  of  until 
ectasy  comes  on,  and  it  is  caused  by  the  resulting  astigmatism,  which  is 
inverse,  or  against  the  rule,  and  is  sometimes  very  high.  Slight  irritation 
of  the  eye — epiphora  and  photophobia — is  present  in  some  cases.  The 
disease  is  held  to  be  a  localised  atrophy  of  the  cornea,  due  to  fatty 
degeneration. 

Treatment  is  not  indicated  until  vision  is  deranged  in  the  stage  of 
ectasy.  Cylindrical  glasses  may  then  prove  of  great  use.  In  many 
advanced  cases  the  galvano-cautery  may  be  applied  to  the  protruding 
part,  or  it  may  be  abscised  and  covered  with  a  conjunctival  flajD. 

Tumours  of  the  Cornea. 

Primary  tumours  of  the  cornea  are  extremely  rare.  Epithelioma 
and  sarcoma  have  their  origin  not  in  the  cornea,  but  in  the  limbus  of  the 
conjunctiva  (p.  100).  Dermoid  tumours  are  usually  seated  partly  on  the 
conjunctiva  and  partly  on  the  cornea.  Yet  a  very  few  cases  of  papilloma, 
epithelioma,  and  fibroma  are  recorded  as  taking  their  origin  in  the 
cornea.     Corneal  cysts  also  occur. 

Dermoid  Tumours. — These  are  of  a  pale  yellow  or  white  colour,  and 
in  size  are  from  that  of  a  split  pea  to  that  of  a  cherry.  They  are  smooth 
on  the  surface,  dry  looking,  and  sometimes  have  fine  hairs,  and  sit  usually 
at  the  outer  and  lower  margin  of  the  cornea.  In  structure  they  resemble 
that  of  the  skin. 

They  often  increase  in  size  at  puberty,  and  the  hairs  then  grow.  They 
are  congenital  tumours,  supposed  to  be  due  to  an  arrest  in  development, 
and  are  sometimes  accompanied  by  coloboma  of  the  upper  lid.  They  often 
have  a  tendency  to  extend  over  the  cornea.  If  this  tendency  be  present, 
the  tumour  must  be  removed  by  dissecting  it  off  the  cornea,  care  being 
taken  not  to  go  into  the  deep  layers  of  the  latter. 

Injuries  of  the  Cornea. 

Foreign  Bodies  in  the  Cornea,  such  as  particles  of  iron,  stone, 
coal,  etc.,  are  amongst  the  most  common  of  all  accidents  to  the  body. 
The  pain  caused  by  these  foreign  bodies  is  very  considerable.  The 
dangers  which  may  follow  on  their  presence  in  the  cornea  depend 


154 


DISEASES   OF    THE   EYE. 


[chap.  v. 


partly  upon  whether  or  not  they  carry  infection,  and  partly  upon 
the  depth  at  which  they  lie  buried  in  the  cornea.  The  deeper  a 
foreign  body  lies,  the  more  difficult  will  be  its  removal,  and  the 
greater  must  be  the  laceration  of  the  cornea  caused  by  that  proceed- 
ing. A  foreign  body  which  carries  infection  will  be  more  likely  to 
set  up  serious  inflammatory  reaction  than  one  which  is  aseptic,  or 
nearly  so.  For  this  reason  it  is  important  to  ascertain,  if  possible, 
the  origin  of  the  foreign  body,  although  an  apparently  aseptic  origin 
must  not  set  at  rest  all  fear  on  this  point.  Chips  of  hot  metal  or 
glass  are,  from  their  temperature,  aseptic. 

Many  foreign  bodies  are  so  small  as  to  defy  detection,  until 
the  cornea  is  searched  with  the  oblique  illumination — an  aid  which 
should  always  be  made  use  of,  when  the  symptoms  or  history  in 
the  remotest  degree  suggest  the  presence  of  a  foreign  body. 

A  foreign  body  which  lies  quite  superficially  in  the  epithelium 
is  easily  removed  by  gentle  wiping  with  a  clean  camel' s-hair  pencil, 
or  soft  cloth.  Those  which  lie  deeper  require  instrumental  inter- 
ference, in  the  following  manner  : — 

The  eye  having  been  thoroughly  cocainised,  the  patient  is 
seated,  and  leans  his  head  €|ainst  the  chest  of  the  surgeon,  who 

stands  behind  him  (Fig.  67).  With 
the  index-finger  of  the  left  -hand 
the  surgeon  then  lifts  the  upper 
lid  of  the  injured  eye,  pressing 
the  margin  of  the  lid  upwards  and 
backwards,  while  with  the  second 
finger  he  depresses  the  lower  lid  in 
a  similar  manner.  By  this  means 
the  eyelids  are  held  open,  and  also, 
to  a  great  extent,  the  motions  of 
the  eyeball  are  controlled.  The 
foreign  body  is  now  pricked  out  of 
the  cornea  with  a  special  needle, 
with  as  little  injury  of  the  general 
surface  as  possible,  the  patient  all  the  while  directing  his  gaze  steadily 
at  some  given  point.  If  the  foreign  body  be  deep  in  the  layers  of 
the  cornea,  it  must  be  dug  out,  as  it  were  ;  and  a  minute  gouge  is 
made  for  this  purpose.  In  cases  where  a  chip  of  iron  or  steel  has 
lain  for  some  time  in  the  cornea,  after  its  removal  a  small  ring  of 


Fig.  G7. 


CHAP,  v.]  THE    CORNEA.  155 

rust  will  be  seen  surrounding  the  spot  previously  occupied  by  the 
foreign  body.  This  rust-ring  is  in  the  true  cornea,  and  must  be 
carefully  scraped  away,  or  the  recovery,  by  necrosis  of  the 
affected  part,  will  be  much  slower,  and  the  resulting  opacity  much 
greater. 

Care  must  be  taken  not  to  infect  the  cornea  in  the  removal 
of  a  foreign  body,  and  consequently  thorough  aseptic  precautions 
must  be  taken,  especially  as  regards  the  instrument  used.  A 
dressing  is  worn  until  the  epithelium  is  regenerated — i.e.  for  a 
day  or  two. 

The  magnet  is  of  no  use  for  the  removal  even  of  superficially 
seated  foreign  bodies  of  steel  or  iron  in  the  cornea. 

Sometimes  a  foreign  body  in  the  cornea  will  be  long  enough 
to  protrude  somewhat  into  the  anterior  chamber,  and  there  is 
danger  that,  in  the  attempts  at  removal,  it  may  be  pushed  into  it. 
In  such  cases  it  is  necessary  to  pass  a  keratome  through  the  cornea, 
and  behind  the  foreign  body,  so  as  to  provide  a  firm  base  against 
which  to  work,  or  the  keratome  may  be  made  to  push  the  foreign 
body  forwards. 

The  wing-cases  of  small  beetles  and  scales  of  seeds  may  get 
into  the  eye,  and  adhere  to  the  cornea,  usually  at  the  limbus,  by 
their  concave  surface,  where  they  may  remain  for  several  days,  or 
even  for  weeks. 

Simple  Traumatic  Losses  of  Substance,  or  Abrasions,  of  the 
surface  of  the  cornea,  involving  the  most  anterior  layers  of  the 
true  cornea,  or  perhaps  merely  the  epithelium,  are  very  common 
from  rubs  or  scratches  with  branches  of  trees,  finger-nails,  etc., 
etc.  Fluorescine  is  especially  useful  for  diagnosis  in  these  cases. 
There  is  much  pain,  photophobia,  and  lacrimation ;  the  most 
superficial  lesions  being  the  most  painful  owing  to  laceration  of 
the  nerve-endings  in  the  epithelium.  These  injuries  heal  readily 
if  the  eye  be  protected  with  a  dressing  ;  but  when  neglected,  or  if 
septic  matter  have  been  introduced  when  the  injury  occurred,  or 
if  it  be  present  in  the  conjunctiva  or  lacrimal  sac,  these  losses  of 
substance  are  capable  of  forming  the  startmg-point  ot  corneal 
abscess,  ulcus  serpens,  etc.  The  condition  of  the  lacrimal  apparatus 
and  of  the  conjunctiva  should  be  noted,  so  that,  if  necessary, 
suitable  measures  may  be  taken  to  obviate  infection  from  those 
regions.     In   addition   to  the  dressing  and  bandage,  atropine  and 


156  DISEASES   OF    THE   EYE.  [chap.  v. 

dionine  should  be  used,  along  with  a  weak  sublimate  ointment 
inserted  into  the  conjunctival  sac;  but  no  cocaine,  which  desiccates 
the  epithelium  and  interferes  with  repair.  The  bandage  should  be 
continued  for  some  days  after  the  loss  of  substance  has  been 
repaired. 

A  remarkable  condition  known  as  Recurrent  Abrasion,  or  Disjunction 
of  the  Cornea  (and  also  as  Traumatic  Keratalgia,  and  Recurrent  Traumatic 
Keratalgia),  is  sometimes  observed  to  follow  upon  abrasions  of  the  cornea. 
Healing  of  the  primary  lesion  having  taken  place  in  an  apparently  normal 
manner,  the  patient,  after  an  interval  of  days,  weeks,  or  even  months,  on 
awaking  in  the  morning,  is  seized  with  severe  pain,  similar  to  that  experi- 
enced on  the  occasion  of  the  injury.  On  examination  of  the  eye  a  loss  of 
the  epithelium,  which  may  be  greater  or  less  in  extent  than  was  the  primary 
loss,  is  found  at  the  seat  of  the  original  lesion,  or,  what  is  remarkable,  it 
may  have  taken  place  elsewhere  on  the  cornea.  Or,  more  rarely,  instead 
of  a  loss  of  epithelium,  the  latter  may  be  raised  up  like  a  vesicle,  or  bulla. 
Examination  of  such  cases  has  shown  that  the  epithelial  covering  of  a  great 
part  of,  or  of  the  whole  of,  the  cornea  may  be  easily  lifted  off  with  a  forceps  ; 
in  short,  that  the  cohesion  between  epithelium  and  Bowman's  membrane  far 
beyond  the  immediate  seat  of  the  original  lesion  has  become  imperfect. 
Care  of  the  eye  by  means  of  a  dressing  enables  the  renewed  loss  of  substance 
to  be  rapidly  repaired  ;  but,  after  a  period  of  quiescence,  another  attack 
takes  place  on  awaking  in  the  morning,  or  in  the  course  of  the  night,  and 
such  attacks  may  continue  to  recur,  even  for  several  years.  It  is  charac- 
teristic of  the  affection  that  the  attacks  always  take  place  on  awaking — 
a  circumstance  which  is  explained  by  the  slight  adhesion  between  palpebral 
conjunctiva  and  corneal  epithelium  formed  during  sleep,  so  that  on  the 
lifting  of  the  eyelid  the  loosened  epithelium  is  torn  away,  or  lifted  in  a 
bulla-like  shape.  There  is  some  loss  of  sensation  of  the  surface  of  the 
cornea.  After  one  of  these  attacks,  examination  of  the  corneal  surface  by 
the  usual  methods  may  fail  to  reveal  the  presence  of  a  loss  of  substance, 
and  then  it  may  be  discovered  by  means  of  transmitted  light  from  a  plane 
mirror,  which  will  display  the  defect  as  a  black  mark.  The  corneal  micro- 
scope, too,  is  useful  here. 

The  cause  of  disjunction  of  the  cornea  has  not  been  definitely  ascer- 
tained. The  view  has  been  put  forward,  and  there  is  good  evidence  in 
support  of  it,  that  the  affection  is  due  to  a  very  slight  degree  of  oedema 
of  the  cornea  of  neurogenic  origin,  a  derangement  of  the  peripheral  endings 
of  the  fifth  nerve  in  the  cornea  having  been  produced  by  the  original  injury. 

Treatment. — Cocaine,  owing  to  the  disorganising  effect  it  has  on  the 
corneal  epithelium,  is  not  to  be  used  at  all,  or  as  sparingly  as  possible.  A 
carefully  applied  dressing  is  important,  and  should  be  worn  for  long — 
it  may  be  weeks — after  the  recurrent  lesion  seems  to  be  quite  well.  An 
operative  measure — namely,  the  removal  with  the  forceps  of  the  entire 
corneal  ei^ithelium  or  as  much  of  it  as  easily  comes  away — is  very  effectual. 
The  denuded  region  is  soon  again  covered  over  with  epithelium,  and  this 
new  growth  adheres  in  a  healthy   manner  to  its  bed.      Some  surgeons 


CHAP,   v.]  THE    CORNEA.  157 

remove  the  loosened  epithelium  with  a  camel's-hair  pencil  moistened  with 
chlorine  water,  and  others  take  it  away  with  a  curette.  The  insertion  into 
the  conjunctival  sac  of  a  non-irritating  ointment  every  night  at  bed-time 
is  a  most  useful  adjunct  in  the  treatment  by  dressing  or  operation. 

Blows  on  the  eye,  amongst  other  lesions,  are  liable  to  cause  corneal 
bullae,  the  walls  of  which  consist  of  Bowman's  membrane  and  the  epithe- 
lium. In  some  cases  these  bullae  contain  blood,  derived  no  doubt  from 
the  ruptured  canal  of  Schlemm.  Such  bullae  may  also  form  after  burns 
with  lime,  etc. 

Hsemorrhagic  Discoloration  of  the  Cornea  is  another  condition  caused  by 
blows  on  the  eye.  It  produces  a  greenish  or  a  reddish-brown  colour  in 
the  cornea.  Haemorrhage  in  the  anterior  chamber  is  always  present  at 
first.  At  first,  too,  the  discoloration  occupies  the  whole  cornea,  and  after 
a  time  begins  to  clear  up  from  the  margin  towards  the  centre.  The 
l")rognosis  for  vision  is  good,  if  the  eye  be  otherwise  sound,  but  the 
absorption  of  the  colouring  matter  in  the  cornea  is  excessively  slow,  and 
as  much  as  two  or  three  years  or  more  may  elapse  before  the  process  is 
complete.  Treacher  Collins  has  ascertained  that  the  peculiar  discolora- 
tion in  these  cases  is  due  to  the  presence  of  haematoidin,  which  he 
believes  enters  the  cornea  from  the  haemorrhage  in  the  anterior  chamber 
tlirough  Descemet's  membrane  by  a  process  of  diffusion.  He  did  not 
find  any  red  blood-corpuscles  in  the  cornea. 

Injuries  of  the  Cornea  with  Caustic  Substances.— The  caustic 
substances  whicli  need  enter  into  consideration  liere  are  those  that 
most  commonly  come  in  contact  with  the  cornea  and  conjunctiva, 
either  accidentally  or  maliciously.  They  are  lime,  ammonia,  and 
caustic  potash  ;  also  nitric  acid,  sulphuric  acid,  and  acetic  acid. 
The  subjects  of  these  accidents  sufier  great  pain,  and  on  presenting 
themselves  soon  afterwards  the  eyelids,  even  if  not  injured,  are 
found  to  be  swollen  and  discoloured,  and  it  is  difficult  to  open 
them  in  order  to  examine  the  state  of  the  eye.  There  is  chemosis, 
and  great  irritation. 

Burns  of  the  cornea  from  lime  or  mortar,  or  whitewash  con- 
taining lime,  are  not  uncommon  amongst  those  engaged  about  lime- 
kilns, or  in  the  building  trade.  The  lime  destroys  the  cornea  more 
or  less  deeply,  with  resulting  more  or  less  intense  permanent  cicatricial 
opacity.  The  lime,  moreover,  enters  into  chemical  combination 
with  the  corneal  mucin  or  albumen,  which  causes  further  opacity. 

As  soon  as  possible  after  lime  has  entered  the  eye,  it  should 
be  removed  as  thoroughly  as  possible  by  means  of  forceps  and  free 
washing  out  "with  water ;  or,  better  still,  with  saturated  solution 
of  sugar,  ^Yhich  forms,  with  whatever  loose  lime  may  be  present, 
a  substance  that  can  be  more  readilv  removed. 


158  DISEASES    OF    THE   EYE.  [chap.  v. 

The  removal  of  such  albuminate  of  lime  as  remains  fastened 
deeply  in  the  cornea  is  difficult  to  effect  ;  but  when  the  immediate 
irritation  has  somewhat  subsided,  the  eye  having  been  cocainised, 
a  10  per  cent,  solution  of  neutral  ammonium  tartrate  may  be  used. 

The  treatment  of  injuries  with  ammonia,  caustic  potash,  and 
other  metallic  caustics,  is  the  same  as  that  of  injuries  with  lime. 

Burns  of  the  cornea  with  nitric,  sulphuric,  acetic,  and  other 
caustic  acids  are  treated  with  a  J  per  cent,  solution  of  caustic  potash 
as  a  bath,  or  poured  into  the  eye  as  above  described,  the  eye  having 
been  cocainised. 

It  is  hardly  necessary  to  state  that,  in  burns  with  such  chemical 
substances,  the  destruction  of  the  corneal  tissues  is  too  often  so 
rapid  and  extensive,  that  no  measure  avails  to  avert  a  degree  of 
opacity  of  the  cornea  that  must  be  seriously  detrimental  to  vision, 
particularly  in  view  of  the  interval  which  in  most  instances  elapses 
between  the  accident  and  the  treatment  of  the  injury.  And  not 
only  is  the  cornea  rendered  opaque,  but  the  inevitable  injuries 
caused  at  the  same  time  to  the  conjunctiva  by  the  caustic,  give 
rise  to  more  or  less  symblepharon  (chap,  xviii.).  In  the  severest 
cases,  suppuration  of  the  cornea  supervenes,  and  the  eye  is  lost 
through  panophthalmitis. 

Perforating  Injuries  of  the  Cornea.— In  these  cases  the  injury 
done  is  rarely  to  the  cornea  alone,  and  at  the  first  inspection  the 
attention  of  the  surgeon  is  occupied  less  with  the  state  of  the  cornea 
than  with  the  question  as  to  whether,  and  to  what  extent,  deeper 
parts  of  the  eye  (iris,  lens,  vitreous  humour,  etc.)  are  involved. 
Another  very  important  point,  which  has  often  to  be  decided,  is 
whether  or  not  the  foreign  body,  which  has  perforated  the  cornea, 
is  contained  in  the  eye.     But  these  matters  belong  to  future  chapters. 

A  perforating  wound  of  the  cornea,  which  does  not  involve 
any  other  part,  is  serious  in  proportion  to  its  extent,  and  to  the 
probability  of  its  being  infected.  Every  perforating  corneal  wound 
is  followed  by  loss  of  the  aqueous  humour,  which  flows  away  through 
the  opening,  and  by  consequent  collapse  of  the  anterior  chamber  ; 
but  this  in  itself  is  not  a  serious  event.  Short  wounds  close  almost 
at  once  (and  through  them  indeed  very  little  of  the  aqueous  humour 
may  flow  ofT),  the  aqueous  humour  is  rapidly  restored,  and  no  harm 
is  done  to  the  eye  beyond  a  slight  opacity,  which,  if  in  the  pupillary 
area,  may  cause  some  defect  of  vision  ;    or,  should  the  wound  be 


THE   CORNEA.  159 


situated  more  peripherally,  and  should  the  iris  have  lain  against  the 
cornea  for  a  while,  an  anterior  synechia  may  form. 

Long  wounds,  which  may  even  occupy  the  cornea  in  its  entire 
diameter  without  directly  involving  any  other  organ  of  the  eye,  are 
almost  certain  to  he  complicated  by  prolapse  of  the  iris  between  the 
lips  of  the  wound  ;  and,  w^hen  healing  takes  place,  the  prolapsed 
portion  becomes  permanently  incarcerated  in  the  cicatrix.  At  the 
least,  ^this  incarceration  causes  irregularity  in  the  curvature  of  the 
cornea,  and  consequent  irregular  astigmatism.  But  it  may  be 
the  starting-point  of  a  staphyloma  of  the  cornea,  it  may  become 
the  cause  of  glaucomatous  intra-ocular  tension,  or,  if  at  any  time  a 
slight  trauma  with  loss  of  substance  of  its  surface  should  occur,  it 
may  take  on  septic  inflammation,  wdiich  may  spread  rapidly  to  the 
deeper  uveal  structures,  leading  to  panophthalmitis  and  loss  of 
the  eye. 

Treatment. — In  small  uncomplicated  perforating  wounds,  without 
prolapse  of  iris,  where  the  aqueous  humour  has  not  yet  formed, 
atropine  should  be  freely  used  if  the  wound  be  towards  the  centre  of 
the  cornea,  or  eserine  if  it  lie  towards  the  periphery,  with  the  object 
of  preventing  adhesions  of  the  iris  to  the  posterior  aspect  of  the 
wound,  and  a  dressing  and  bandage  should  be  applied  to  the  eye. 

In  very  recent  injuries  of  this  kind,  in  which  there  is  a  prolapse  of 
the  iris,  the  prolapsed  portion,  if  not  very  large,  may  sometimes  be 
reposed  with  a  spatula  or  fine  probe,  aided  by  the  action  of  atropine 
or  eserine,  according  to  the  position  of  the  wound.  But  in  many 
instances  this  attempt  will  prove  futile,  while  in  those  in  which 
there  is  suspicion  of  septic  infection,  it  is  unwise  to  make  it.  In 
either  circumstance  the  prolapsed  portion  of  iris  should  be  snipped 
of!  at  its  base.  It  is  not  enough  to  abscise  a  portion  of  the  summit 
of  the  prolapse.  The  prolapsed  iris  must  be  seized  with  an  iris- 
forceps,  drawn  forward  so  as  to  loosen,  so  far  as  possible,  any  ad- 
hesions between  it  and  the  lips  of  the  wound  (or  the  adhesions  may 
previously  be  separated  by  a  probe  passed  round  the  edges  of  the 
wound),  and  cut  off  close  to  the  cornea.  This  affords  the  best  hope 
that  the  iris  may  recede  into  the  anterior  chamber,  without  any  of 
it  becoming  incarcerated  in  the  corneal  wound  while  healing.  In 
badly  lacerated  wounds  it  is  sometimes  desirable  to  transplant 
conjunctiva  over  them  in  order  to  promote  the  healing  process 
and  to  consolidate  the  cicatrix. 


160  DISEASES   OF   THE   EYE.  [chap.  v. 

In  cases  which  are  not  recent,  the  adhesions  between  cornea  and 
prolapsed  iris  will  have  become  so  firm,  that  it  will  not  be  possible 
to  separate  them  by  any  means,  and  the  prolapse  must  be  allowed 
to  become  cicatrised  over,  the  tension  of  the  eye  being  kept  low  by 
means  of  eserine,  and  transplantation  of  conjunctiva  being  per- 
formed, to  the  end  that  a  firm  and  flat  cicatrix  may  be  obtained. 

Opacities  of  the  Cornea. 

Nebula,  Macula,  Leucoma. — These  terms  are  applied  to  opacities 
of  varying  degrees  in  the  cornea,  resulting  from  disease  or  injury. 
They  are  really  scars  of  the  cornea,  due  to  the  formation  of  irregular 
fibrous  tissue,  and  as  such  are  not  accompanied,  as  keratitis  is, 
by  ciliary  congestion  or  photophobia.  Lesions  which  involve  the 
epithelium  of  the  cornea  alone,  undergo  repair  without  any  resulting 
opacity.  The  term  nebula  is  used  for  very  slight  opacities,  often 
discernible  by  oblique  illumination  alone.  Macula  indicates  a  more 
intense  opacity,  recognisable  by  daylight.  Leucoma  is  a  completely 
non-translucent  and  intensely  white  opacity,  the  result  almost  always 
of  an  ulcer,  which  has  destroyed  most  of  the  true  corneal  tissue  at 
the  affected  place  ;  indeed,  it  is  often  the  result  of  an  ulcer  which  has 
eaten  its  way  quite  through  the  cornea.  In  these  latter  cases  the 
iris  may  have  become  adherent  in  the  corneal  cicatrix,  and  then  the 
term  Adherent  Leucoma  is  employed. 

Eyes  with  an  old-standing  nebulous  condition  of  the  cornea  are 
often  irregularly  astigmatic  or  myopic,  and  cylindrical  or  concave 
glasses  sometimes  aid  the  vision.  It  is  probable  that  this  myopia 
is  caused  by  the  habitual  close  approximation  of  objects  to  the  eye, 
owing  to  the  diminished  acuteness  of  vision  from  the  opacity  of  the 
cornea.  In  children  opacities  of  the  cornea  may  be  the  cause  of 
strabismus  and  nystagmus. 

Treatment. — Little  or  nothing  can  be  done  to  reduce  these 
opacities.  In  slight  and  fresh  cases,  massage  with  the  yellow  oxide 
of  mercury  ointment,  or  instillations  of  5  per  cent,  dionine  may 
render  them  less  intense. 

In  the  case  of  a  dense  central  opacity  with  clear  cornea  at  the 
margin,  an  iridectomy  will  in  some  instances  improve  the  sight. 

The  Operation  of  Tattooing  is  a  valuable  proceeding  for  the  im- 
provement of  the  appearance  of  the  eye  in  cases  of  leucoma.     It  is 


CHAP,  v.]  TH^   CORNEA.  101 

also  useful  for  improvement  of  the  sight,  where  the  nebula  occupies 
only  part  of  the  pupillary  area  of  the  cornea.  In  these  cases,  much 
disturbance  of  vision  is  caused  by  the  dispersion  of  the  light  which 
make  its  way  through  the  nebula  ;  and  when,  by  tattooing  the  scar, 
all  light  is  prevented  from  getting  through  it,  more  distinct  vision 
is  enjoyed  w^th  that  part  of  the  cornea,  opposite  the  pupil,  which 
is  absolutely  clear. 

The  material  used  is  fine  Indian  ink  rubbed  into  a  very  thin  paste. 
The  eye  having  been  cocainised,  the  leucoma  is  spread  over  with  this 
paste,  and  then  covered  with  innumerable  punctures  by  means  of 
de  Wecker's  multiple  tattooing-needle,  or  with  an  ordinary  discission 
needle.  The  coloration  remains  sufficiently  intense  for  some  months, 
but  then  often  begins  to  get  pale,  owing  to  removal  of  the  pigment. 
The  pigmentation  lasts  longer,  if  a  single  grooved  needle  be  used. 
The  pigment  is  placed  in  the  groove  of  the  instrument,  which  is  then 
passed  into  the  leucoma,  in  a  plane  parallel  to  its  surface.  On  with- 
drawal of  the  needle  the  pigment  remains  behind.  A  large  number 
of  such  channels  must  be  made  in  close  proximity  to  each  other,  until 
the  desired  intensity  of  colour  is  obtained.  Some  operators  remove 
the  corneal  epithelium  over  the  part  to  be  tattooed,  in  order  to 
facilitate  the  entrance  of  the  colouring  matter  into  the  true  cornea. 

In  tattooing  the  cornea,  the  eye  must  not  be  fixed  with  a  toothed 
forceps,  or  else  the  conjunctiva  may  be  tattooed.  A  forceps  armed 
with  rubber  is  used,  or  the  eye  can  be  fixed  by  the  surgeon  with  his 
fingers,  which  at  the  same  time  take  the  place  of  a  speculum  (Fig.  67). 

Keratoplasty  or  Transplantation  of  a  Portion  of  Clear  Cornea  from  a 
freshly  enucleated  human  eye  has  been  performied  in  many  cases  of  leu- 
coma where  sight  could  not  be  restored  by  an  iridectomy.  Formerly  these 
operations,  although  perfectly  successful  in  a  surgical  sense — i.e.  in  so  far 
as  the  healing-in  of  the  transplanted  flap  was  concerned — with  few  excep- 
tions, ended  in  disappointment,  in  conse  j^uence  of  the  flap  not  retaining  its 
transparency.  But  of  late  several  successful  cas3s  have  been  recorded,  in 
which  the  flap  remained  clear. 

The  essential  points  to  be  attended  to  for  a  successful  issue  of  the 
operation  are  : — The  flap  must  be  taken  from  a  human  cornea.  There 
should  be  perfect  asepsis.  The  membrane  of  Descemet  must  not  be  per- 
forated, and  the  flap  must  be  treated  gently  and  not  bruised  by  handling 
with  instruments. 

The  method  of  proceeding  consists  in  removing,  with  a  von  Hippel 
trephine,  a  disc  of  at  least  5mm.  in  diameter,  from  the  centre  of  the  leucoma, 
and  inserting  in  its  place  a  similar  disc  taken  from  a  clear  cornea.      In 

11 


162  DISEASES   OF   THE   ETE.  [cha^.  v. 

order  to  avoid  perforation  of  Descemet's  membrane,  the  trephine  is  provided 
with  a  guard  by  which  the  depth  of  the  incision  can  be  regulated.  The 
disc  of  cornea  isolated  by  the  trephine  is  dissected  off  by  passing  a  Gra?fe's 
or  special  bent  knife  in  the  incision  and  dividing  the  base  of  the  flap  with 
the  blade  of  the  knife  held  parallel  to  tlie  corneal  surface.  The  flap  is  then 
carried  on  the  blade  to  the  defect  prepared  for  it  in  the  leucoma.  It  may 
be  very  gently  pressed  into  its  place  with  a  blunt  probe.  A  bandage  is 
applied  and  is  not  removed  for  forty-eight  hours. 

The  clear  flap  for  transplantation  may  be  obtained  from  a  still-born 
child,  or  sometimes  even  from  the  marginal  portion  of  the  cornea  of  the 
leucomatous  eye. 

Magitot  has  shown  that  the  tissues  of  an  eye  may  be  kept  alive  for 
eight  or  fourteen  days  by  preserving  it  at  a  constant  temperature  of  5°  to 
8°  Centigrade  (41°  to  40°  Falirenheit)  immersed  in  hsemolysed  serum  ;  the 
serum  must  be  human  in  the  case  of  a  human  eye.  He  has  also  succeeded 
in  transplanting  successfully  a  flap  from  a  cornea  preserved  in  this  way 
(Deferred  Keratoplasty). 

Lohlein  has  successfully  performed  the  following  operation  for  corneal 
transplantation  : — From  the  opaque  cornea  a  rectangular  flap  5  mm.  in 
width,  extending  from  the  upper  to  the  lower  margin,  is  removed.  The 
parallel  boundaries  of  the  flap  are  defmed  with  a  fork-like  instrument  at 
the  end  of  each  prong  of  which  is  a  small  circular  knife,  with  which  there 
is  but  little  danger  of  the  cornea  being  perforated.  At  the  upper  end  of 
the  double  incision  a  short  but  thick  conjunctival  flap  is  dissected  up. 
This  conjunctival  flap  is  then  seized  with  a  forceps,  which  is  of  about  its 
own  breadth,  a  Grsefe's  cataract  knife  is  passed  behind  it,  and  with  short 
strokes  is  made  to  enter  the  scleral  tissue  8.t  the  limbus  ;  so  that,  along 
with  the  conjunctival  flap  already  formed,  a  narrow  band  of  scleral  tissue 
is  obtained.  The  forceps  now  seizes  this  scleral  band,  and  the  edge 
of  the  knife  is  reversed,  and,  with  sawing  motions,  is  made  to  cut  through 
the  substance  of  the  cornea  at  the  required  depth,  taking  with  it  the  flap 
of  corneal  tissue  originally  delimitated.  At  the  lower  corneal  margin  a 
narrow  band  of  scleral  tissue,  and  a  short  thick  conjunctival  flap  are 
formed  by  the  knife  in  cutting  out.  The  corneal  flap  is  left  in  situ,  while, 
in  a  precisely  similar  manner,  a  similar  flap  is  taken  from  the  clear  cornea 
of  an  eye  which  is  about  to  be  excised.  This  second  flap  is  then  spread 
out  on  the  wounded  surf  ace  in  the  fu'st  ey»  ,  the  utmost  pains  being  taken 
that  during  the  transfer  the  flap  suffers  not  the  slightest  bruising  or  other 
injury.  The  flap  is  fastened  in  its  place  by  three  or  four  points  of  suture  at 
either  end,  the  needles  being  passed  through  the  narrow  bands  of  scleral 
tissue,  and  the  episcleral  tissue  of  the  eye.  The  conjunctival  flaps  are 
spread  over  the  sutures.  Only  warm  normal  sahne  solution  is  to  be  used 
for  douching  the  field  of  operation. 

Arcus  Senilis  (Gerontoxon). — This  is  a  change  which  is  developed 
in  the  cornea  without  previous  inflammation.  It  presents  the 
appearance  of  a  greyish  line  all  around  and  a  little  inside  the  margin 
of  the  cornea.     It  commences  and  is  always  most  marked  above  and 


CttAf.  v.]  THE   CORNEA.  163 

below,  never  advancing  farther  towards  its  centre.  It  is  more  com- 
mon in  elderly  people,  bnt  is  sometimes  seen  in  youth,  and  even  in 
childhood.  No  functional  changes  are  caused  by  it,  nor  does  it 
interfere  with  the  healing  of  a  wound  which  may  be  made  in  that 
part  of  the  cornea.  Arcus  senilis  is  caused  by  a  peculiar  fatty 
'degeneration  of  the  corneal  cells  and  fibrillae. 


CHAPTER    VI. 
DISEASES   OF   THE    SCLEROTIC. 

The  sclerotic  or  protective  coat  of  the  eye  is  continuous  with  the 
substantia  propria  of  the  cornea.  Its  thinnest  part  is  in  the  ciliary 
region,  hence  when  rupture  occurs  it  is  usually  here.  The  anterior 
ciliary  vessels  also  perforate  the  sclera  in  this  situation,  and  intra- 
ocular growths  make  their  way  out  along  them. 

Owing  to  its  simple  fibrous  structure  and  poor  vascular  supply, 
the  sclerotic  is  not  liable  to  many  diseases.  In  fact  it  usually  becomes 
affected  either  from  the  subconjunctival  tissue  overlying  it  or  from 
the  ciliary  portion  of  the  uveal  tract. 

In  scleritis,  as  in  conjunctivitis,  iritis  and  keratitis,  the  white  of 
the  eye  becomes  injected.  But  scleritis  differs  from  conjuncti- 
vitis, in  the  violet  colour  of  the  congestion,  which  is  also  ciliary 
(Plate  II.  Fig.  5),  in  its  restriction  to  certain  areas  of  the  circum- 
corneal  zone,  and  in  the  absence  of  secretion.  From  iritis,  the 
characteristic  appearances,  to  be  described  later  on,  will  readily 
distinguish  it. 

Scleritis  attacks  only  that  part  of  the  sclerotic  which  is  anterior 
to  the  equator  of  the  eyeball,  and  it  is  either  superficial  or  deep. 
The  superficial  form  is  known  as  episcleritis.  Yet  it  is  not  always 
possible  to  distinguish  between  these  two  forms  in  a  given  case,  as 
the  appearances  in  the  early  stages  are  very  similar.  They  are 
probably  only  different  degrees  of  the  same  disease.  But  the  neces- 
sity of  admitting  the  existence  of  two  forms  depends  upon  the  different 
course  they  each  take  ;  the  superficial  form  being  a  relatively  harm- 
less disease,  while  the  deep  form  entails  serious  consequences. 

Episcleritis. — Of  this  two  kinds  are  recognised  : — 1.  Periodic 
Transient  Episcleritis  (Fuchs),  or  Hot  Eye  (Hutchinson).  2.  Epi- 
scleritis of  the  usual  type. 

Periodic  Transient  Episcleritis  is  characterised  by  frequently  recurring 
attacks  of  inflammation  of  the  episcleral  connective  tissue,  giving  rise  to 

164 


CHAP.  VI.]  THE   SCLEROTIC.  165 

a  vascular  injection  of  a  violet  hue,  but  without  any  catarrhal  or  other 
secretion,  or  any  hard  infiltration,  as  in  episcleritis  of  the  usual  type. 
It  rarely  attacks  the  whole  sclerotic  at  one  time,  but  is  commonly  confined 
to  a  quadrant  or  more,  and  wanders  from  one  place  to  another.  When 
the  attack  subsides,  there  is  no  stain  left.  The  attack  may  be  confined 
to  one  eye,  or  it  may  be  in  both,  or  it  may  affect  sometimes  one  eye  and 
sometimes  the  other.  Pain,  lacrimation,  and  photophobia  are  present  in 
varjdng  degrees.  Sometimes  the  eyelids  are  swollen.  Occasionally  the 
iris  and  ciliary  body  become  inflamed,  and  also  the  cellular  tissue  of 
the  orbit,  with  resulting  exophthalmos.  The  attacks  last  from  one  or 
two  days  to  several  weeks,  and  may  recur  once  or  twice  a  year  and  at 
intervals  of  only  two  or  three  weeks.  Patients  are  usually  liable  to  the 
disease  for  several  years  of  their  life.  It  attacks  adults  of  middle  age 
for  the  most  part.  Some  assign  gout  as  the  cause  ;  while  others  do  not 
find  any  symptoms  of  that  diathesis  in  their  patients.  Rheumatism  and 
malaria  seem  sometimes  to  produce  it,  and  some  observers  hold  that 
episcleritis  and  scleritis  are  frequently  of  tubercular  or  of  syphilitic  origin. 
It  is  probable,  too,  that  it  may  be  caused  by  a  gonococcus  toxaemia,  even 
long  after  the  primary  disease  has  been  cured. 

Treatment. — The  long  continuance  of  most  of  the  cases  shows  that 
treatment  has  but  little  influence  over  the  disease.  Quinine  and  salicylate 
of  soda  internally  are  the  remedies  likely  to  be  of  use,  with  local  warm 
fomentations,  dionine,  and  a  protective  dressing  during  an  attack. 

Episcleritis  of  the  usual  type.  This  appears  as  a  circumscribed 
purplish,  rather  than  red,  spot  (Plate  II.  Fig.  5),  close  to,  or  2  to  3  mm. 
removed  from,  the  corneal  margin.  It  is  often  unattended  by 
pain,  unless  when  the  eye  is  exposed  to  irritating  causes,  and  need 
not  be  elevated  above  the  level  of  the  sclerotic  ;  but  in  severe 
cases  there  is  a  decided  node  at  the  affected  place,  with  more  or 
less  pronounced  pain,  which  is  increased  on  pressure.  All  the 
symptoms  disappear  in  the  course  of  a  few  weeks,  and  reappear 
at  an  adjoining  place  ;  and  in  this  way,  in  time,  the  whole  circum- 
ference of  the  sclerotic  will  have  been  attacked.  The  duration  of 
the  affection  is  usually  long  ;  and,  in  those  instances  where  the 
entire  sclerotic  becomes  affected  by  degrees,  the  process  may  last 
for  years,  on  and  off.  Both  eyes  are  often  affected.  The  disease 
is  liable  to  leave  behind  it  a  dusky  discoloration  of  the  sclerotic 
where  each  node  was  seated,  but  otherwise  no  harm  to  the  eye 
ensues.  The  patient  should,  as  soon  as  possible,  be  informed  of 
the  tedious  nature  of  the  affection.  Very  mild  attacks  of  episcleritis 
will  be  met  with,  which  pass  away  in  a  few  days,  and  do  not  recur. 

Causes. — The  affection  is  often  of  gouty  or  rheumatic  origin. 
It  occurs  sometimes  in  persons  of  tubercular  or  syphilitic  constitu- 


166  DISEASES   OF    THE  EYE.  [chap.  vi. 

tion ;  and  it  is  more  frequent  in  senior  adults  than  in  children  or 
young  people,  and  more  commonly  attacks  women  than  men. 

Treatment. — Local  treatment  should  be  confined  to  protection 
with  dressing  and  bandage,  warm  fomentations,  and  dionine.  In 
addition  to  these,  massage  should  be  used,  if  there  be  not  too  great 
tenderness  on  pressure.  Leeching  at  the  external  canthus  is  of 
use  when  the  pain  is  severe.  As  regards  internal  remedies,  where 
a  syphilitic  taint  is  present,  mercury  should  be  employed  ;  if  struma, 
cod-liver  oil,  maltine,  etc.  ;  or  if,  as  is  most  frequently  the  case, 
rheumatism  be  the  source  of  the  evil,  large  doses  of  salicylate  of 
sodium  (say  20  grains  four  times  a  day)  will  often  be  found  to  act 
well.  Salicylate  of  lithium  is  recommended  in  preference  to  the 
sodium  salt  by  some.  Iodide  of  potassium  in  large  doses  (20  grains 
four  times  a  day,  or  more  frequently)  is  a  useful  remedy  in  some 
cases  of  this  obstinate  disease. 

Deep  Scleritis. — Here  the  whole  of  the  anterior  part  of  the  sclerotic 
is  more  likely  to  be  affected  than  in  the  milder  forms  ;  although 
cases  often  enough  occur  where  only  an  isolated  node  is  present  at 
one  time. 

The  progress  of  the  case  alone  can  render  the  diagnosis  between 
this  and  the  milder  forms  certain,  and  hence  the  importance  of  a 
guarded  prognosis  in  the  early  stages  of  every  case  of  scleritis. 
The  chief  characteristics  of  deep  scleritis  are  : — 1.  Localised  conges- 
tion and  swelling,  with  the  appearance  of  yellowish  nodules,  which 
do  not  as  a  rule  soften  or  caseate.  2.  Discoloration  of  the  sclera. 
3.  Sclerotising  opacities  of  the  cornea.  4.  Frequent  relapses.  In 
this  deep  form  changes — thinning  and  softening — of  the  scleral  tissue 
take  place,  which  render  the  latter  less  resistant,  and  consequently 
dispose  it  to  become  ectasied  even  by  normal  intra-ocular  tension. 
The  result  of  this  is  a  bulging  (staphyloma)  of  the  anterior  part  of 
the  eyeball  (p.  171).  This  bulging  produces  myopia,  and  has  a 
deleterious  effect  upon  the  sight ;  but,  at  a  later  period,  vision  is 
often  wholly  destroyed  by  secondary  glaucoma.  It  may  happen 
that  the  thinning,  etc.,  of  the  sclerotic  affects  only  a  portion,  and 
not  the  whole,  of  the  anterior  surface  ;  and  in  such  a  case  the 
resulting  staphyloma  will  be  confined  to  that  part  of  the  sclerotic. 
A  staphyloma,  whether  total  or  partial,  presents  a  bluish-grey 
appearance,  due  to  the  uveal  tract  shining  through  the  thinned 
sclerotic. 


CHAP.  VI.]  THE   SCLEROTIC.  167 

In  deep  scleritis,  either  with  or  without  staphylomatous  changes, 
the  process  often  extends  some  distance  into  the  deep  layers  of 
the  cornea,  giving  rise  to  sclerotising  opacity  (Plate  II.  Fig.  5). 
Iritis,  punctate  deposits  on  the  back  of  the  cornea  indicating  cyclitis, 
chorioiditis,  and  opacity  of  the  vitreous  humour  are  not  uncommon 
complications,  especially  in  strumous  subjects. 

Causes. — Young  adults  are  the  most  common  subjects  of  deep 
scleritis,  and  it  attacks  females  more  often  than  males.  Syphilis, 
congenital  or  acquired,  rheumatism,  gout,  tubercle,  and  disturbances 
of  menstruation  are  the  most  common  assignable  causes,  but  it 
is  probable  there  are  others  which  are  as  yet  undefined. 

Treatment. — There  are  few  diseases  less  amenable  to  treatment. 
When  any  definite  cause  can  be  assumed  to  be  present,  the  remedy 
suitable  to  it  is  of  course  indicated.  Besides  this,  a  dressing  of  a 
thick  layer  of  cotton  wool  to  be  constantly  worn  when  only  one 
eye  is  affected,  warm  fomentations,  dionine,  dry  cupping  on  the 
temple,  or  the  artificial  leech,  complete  rest  of  the  eyes,  and  protec- 
tion with  dark  glasses  are  to  be  recommended. 

When  all  acute  inflammation  has  passed  away,  an  iridectomy 
is  sometimes  indicated — either  for  optical  purposes,  when  the  pupil 
is  obstructed  by  corneal  opacity,  or  for  the  purpose  of  reducing 
glaucomatous  tension,  or  of  diminishing  a  staphyloma. 

Syphilitic  Gumma  of  the  Sclerotic. — This  is  rare.  The  diagnosis 
depends  to  a  great  extent  on  the  history  and  co-existing  signs  of  syphilis. 
The  appearance  usually  presented  is  that  of  one  or  more  rounded  tumours, 
of  sizes  which  may  vary  from  that  of  a  pea  to  that  of  a  hazel  nut.  These 
tumours  are  covered  with  a  highly  injected  conjunctiva,  through  which 
the  yellowish  colour  of  the  gummata  shines.  They  are  seated  close  to 
the  corneal  margin — and,  consequently,  give  rise  to  opacity  in  the  neigh- 
bouring sector  of  the  latter — but  may  extend  as  far  as  the  equator,  or 
even  farther  back.  As  a  rule  there  is  much  pain  in  the  eye  and  head. 
Iritis,  retinitis,  and  vitreous  opacities  may  form  complications.  In 
advanced  stages  the  sclerotic  may  be  perforated,  or  become  staphy- 
lomatous, and  the  gumma  may  extend  to  the  interior  of  the  eye,  producing 
detachment  of  the  retina,  and  atrophy  of  the  eyeball. 

Treatment. — In  the  early  stages,  an  energetic  inercurial  treatment  is 
capable  of  producing  such  perfect  cures,  that  not  even  a  slight  discolora- 
tion of  the  sclerotic  remains. 

Tubercle  of  the  Sclerotic. — Apart  from  those  cases  of  more  or  less 
diffused  episcleritis  and  scleritis  w^hich  may  be  due  to  tubercle,  primary 
tubercle  of  the  sclerotic  sometimes  occurs  as  a  solitary  nodule  which  may 
ulcerate.  We  have  seen  such  a  nodule  near  the  corneal  margin  (Fig.  68). 
It  measured  4  mm.  at  its  base,  and  towards  its  apex  was  of  a  pearly  white 


108  DISEASES   OF    THE   EYE.  [chap.  vi. 

colour,  while  the  vessels  of  the  conjunctiva  covering  it  were  much  injected. 

The  abscess  was  incised,  and  the  cavity  in  the  substance  of  the  sclerotic 

thoroughly  curetted,  after  which  a  rapid  cure  took  place.     Examination 

of    the  contents   of    the   abscess   demonstrated 

the  presence  of  the  tubercle  bacillus. 

But  in  the  majority  of  cases  of  tubercle  of 
the  sclerotic,  the  disease  is  an  extension  from 
the  root  of  the  iris,  or  from  the  ciliary  body, 
where  it  has  had  its  primary  seat.  Gradually 
the  sclerotic  becomes  thinned  by  the  tubercular 
disease,  staphyloma  forms,  and  finally  rupture 
Fig.   68.  may  take  place.     In  these  cases,  if  the  disease 

be  not  too  advanced,  treatment  with  tuberculin 
may  be  tried,  but  in  later  stages  excision  of  the  eyeball  is  indicated. 

Brawny  or  Annular  Scleritis  is  a  rare  disease,  which  occurs  generally 
in  people  over  sixty  years  of  age.  It  attacks  the  whole  circumference  of 
the  ciliary  region  in  both  eyes,  and  is  characterised  by  rather  flat  brownish- 
red  gelatinous  swellings,  which  may  extend  to  the  tendons  of  the  recti 
muscles.  It  is  a  very  insidious  and  chronic  disease.  Evidences  of  intra- 
ocular involvement,  such  as  sclerosing  keratitis,  punctate  deposits,  posterior 
synechia,  vitreous  opacity,  and  low  tension,  may  be  present.  The  sclera 
is  infiltrated  with  granulation  tissue  with  numerous  plasma  cells,  and 
in  some  cases  there  is  marked  peri-  and  end-arteritis.  The  histology 
points  to  syphilis  as  the  cause.  The  Wasserman  reaction  proved  positive 
in  a  case  of  Verhoeff's,  but  negative  in  others. 


Tumours  of  the  Sclerotic,  as  primary  growths,  are  exceedingly 
rare  ;   but  fibroma,  sarcoma,  and  osteoma  have  been  so  observed. 

Pigment  Spots  of  a  yellowish-brown  colour  are  often  seen  in 
the  sclerotic  close  to  the  corneal  margin.  They  are  congenital, 
and  of  no  importance.  Occasionally  a  black  pigmented  patch  may 
be  associated  with  pigmented  sarcoma  of  the  ciliary  region. 

Injuries  of  the  Sclerotic— Ruptures  and  perforating  wounds  are 
those  which  have  to  be  considered.  Mere  losses  of  substance  may 
be  said  not  to  occur. 

The  danger  attendant  upon  a  rupture  or  perforating  wound  of 
the  sclerotic — apart  from  the  loss  of  the  contents  of  the  eyeball, 
which  is  often  associated  with  it — consists  in  the  possibility  of 
infecting  organisms  being  introduced  into  the  interior  of  the  eye, 
and  there  setting  up  serious  inflammatory  reaction. 

Ruftures  of  the  Sclerotic  are  caused  by  blows  on  the  eye,  and  are 
often  indirect. 

A  common  cause  of  sclerotic  ruptures  amongst  the  agricultural 
population  is  a  blow  from  a  cow's  horn,  while  the  animal  is  being 


CHAP.    VI.] 


THE   SCLEROTIC. 


169 


tied  up  or  fed  in  the  byre,  and  these  cases  are  well  known  in  oph- 
thalmic hospitals.  Blows  with  the  fist  produce  similar  injuries. 
The  lower  and  outer  part  of  the  orbit  is  the  least  prominent,  and 
therefore  the  eye  is  least  protected  here,  and  hence  it  is  commonly 
driven  upwards  and  inwards  by  the  blow,  and  the  sclerotic  usually 
ruptures  from  2  mm.  to  5  mm.  from  the  upper  and  inner  margin  of 
the  cornea,  and  concentrically  with  the  latter.  Often  the  conjunctiva 
is  not  ruptured,  but  bridges  over  the  opening  in  the  sclerotic.  Some 
of  the  contents  of  the  eyeball 
may  have  been  forced  out 
through  the  rupture — e.g.  por- 
tions of  the  uvea,  iris,  and  ciliary 
body,  the  vitreous,  and  the  lens 
(Fig.  69)  ;  and  it  is  sometimes 
difficult  at  first  to  ascertain  the 
exact  state  of  affairs,  by  reason 
of  extra vasated  blood  in  the  an- 
terior chamber,  under  the  con- 
junctiva, and  in  the  tissues  of 
the  eyelids. 

Treatment. — When  the  con- 
junctiva is  not  ruptured,  it  is 
often  advisable  to  confine  treat- 
ment to  the  application  of  a  dressing,  for  the  covering  conjunctiva 
acts  as  a  protection  against  infection  of  the  wound.  Where  serious 
damage  has  not  been  done  to  the  retina,  fair  or  even  good  vision 
may  be  regained  in  many  of  these  cases,  which  at  first  sight  seem 
almost  hopeless  ;  and,  should  perception  of  light  be  present,  one 
may  reasonably  conclude  that  the  retina  is  not  detached.  When 
the  lens  has  been  dislocated  under  the  conjunctiva, — from  whence 
it  can  be  removed,  after  the  sclerotic  opening  has  closed — the 
patient  will  of  course  require  a  glass,  as  after  cataract  operation, 
to  aive  him  the  best  vision. 


Fig.  69. — Rupture  of  the 
sclerotic  above  the  cornea,  with  sub- 
conjunctival dislocation  of  the  lens. 


Small  ruptures  may  occur,  generally  in  young  people,  at  the  limbus 
itself  ;  they  are  accompanied  by  tearing  of  the  conjunctiva  and  usually 
also  by  prolapse  of  the  iris.  Fuchs  has  also  described  incomplete  ruptures 
of  the  inner  surface  of  the  sclera  ;  some  time  after  the  injury  an  area 
of  conjunctival  congestion  is  followed  by  a  dark  discoloration  of  the 
sclerotic,  towards  which  the  pupil  may  be  drawn,  or  the  iris  may  even 
be  invisible  at  a  point  corresponding  to  the  discoloration  of  the  sclera. 


170  DISEASES   OF    THE   EYE.  [chap,  vi." 

Perforating  Wounds  of  the  Sclerotic. — A  large  and  gaping  per- 
forating wound  is  easily  recognised.  A  portion  of  the  chorioid, 
ciliary  body,  or  iris,  according  to  the  position  of  the  wound,  probably 
lies  in  it,  or  part  of  the  vitreous  humour  may  be  found  in  it ;  while 
the  vitreous  humour,  as  seen  through  the  pupil,  will  be  full  of  blood 
(hsemophthalmos) ,  and  blood  may  be  present  in  the  anterior  chamber 
(hyphaema,  vtto,  under  ;  ali^a,  hlood),  especially  if  the  wound  be  far 
forwards.  Small  wounds  may  be  concealed  by  sub-conjunctival 
haemorrhage,  and  here  reduced  tension  of  the  eyeball  is  sometimes 
a  valuable  diagnostic  sign. 

When  inflammatory  reaction  follows  upon  one  of  these  injuries 
it  may  be  either  of  the  purulent  or  plastic  form.  In  the  former  case 
all  the  contents  of  the  eyeball  take  part  in  the  suppuration,  and  we 
term  it  panophthalmitis,  phthisis  bulbi  being  its  ultimate  result. 
In  the  plastic  form,  the  iris  and  ciliary  body  alone  are  implicated,  and 
sight  is  slowly  lost ;  the  eye  here,  too,  becoming  phthisical.  Of  the 
two,  the  latter  process  is  the  more  serious,  as  it  is  prone  to  give  rise 
to  sympathetic  ophthalmitis — a  danger  w^hich  is  not  associated  w4th 
the  eye  lost  through  panophthalmitis. 

Where  the  wound  has  been  produced  by  a  small  foreign  body, 
which  has  remained  in  the  interior  of  the  eye,  the  position  is  much 
more  serious,  and  this  subject  will  be  discussed  in  chap.  xi. 

Treatment. — A  clean-cut  perforating  wound  of  the  sclerotic  may 
heal  without  inflammatory  reaction,  even  when  portions  of  the 
uveal  tract  or  vitreous  humour  are  prolapsed  into  it,  these  prolapsed 
parts  becoming  incarcerated  in  the  cicatrix.  In  cases  where  the 
wound  is  small  (say  less  than  3  mm.),  no  suture  need  be  used  :  a 
carefully  applied  dressing  and  bandage  will  be  sufficient  to  promote 
the  natural  tendency  to  healing.  But,  where  the  wound  is  large  and 
gaping,  any  prolapsed  chorioid,  etc.,  must  be  freely  irrigated  with 
sublimate  lotion,  1  to  5000,  and  completely  reduced — or  if  the  pro- 
lapsed parts,  or  portion  of  them,  cannot  be  reduced,  they  must  be 
abscised — and  the  margins  of  the  wound  drawn  together  by  a  few 
points  of  fine  silk  suture  passed  through  part  of  the  thickness  of 
the  sclerotic  ;  or,  the  sutures  may  be  passed  through  the  conjunctiva 
at  some  distance  from  the  edges  of  the  wound,  the  traction  on  the 
conjunctiva  being  often  sufficient  to  close  the  scleral  wound.  A 
dressing  is  applied  to  each  eye,  and  the  patient  is  confined  to  bed. 

But,  if  the  injury  be  such — very  gaping  wound,  much  loss  of 


•CHAP.    VI.] 


THE  SCLEROTIC. 


171 


contents  of  the  eyeball,  or  extensive  intra-ocular  h?emori'liage — as 
to  render  restoration  of  useful  sight,  or  at  least  retention  of  the 
shape  of  the  eyeball,  beyond  reasonable  hope,  it  is  wiser  to  remove 
the  eyeball  at  once,  rather  than  to  run  the  risk  of  sympathetic 
ophthalmitis  without  compensating  advantage. 

Staphyloma  of  the  Sclerotic. — The  sclerotic  may  become  ectasied 
(stapliylomatous)  either  uniformly  or  in  the  form  of  localised  bulgings. 
The  most  common  condition  under  which  we  see  a  uniform  stretching 
of  the  membrane  is  in  myopia,  where  the  posterior  pole  of  the  eyeball 
and  its .  neighbourhood  become  distended  as  will  be  described  in 
chap.  xvi.  In  buphthalmos  the  whole  sclerotic  is  stretched  and 
the  cornea  participates  in  the  distension  (chap.  ix.).  Localised 
staphylomata  of  the  sclerotic  occur  only  in  the  anterior  segment 
of  the  eyeball,  and  are  due  to  thinning,  and  consequent  diminished 
resistance,  so  that  the  affected  part  can  no  longer  withstand  the 
normal  intra-ocular  pressure.  This  thinning  is  the  result  of  deep 
scleritis  (p.  166),  gummata,  or  tubercular  disease.  After  a  time, 
high  intra-ocular  tension — brought  on  by  closure  of  the  angle  of  the 
anterior  chamber,  resulting  from  the  distortion  of  the  eyeball,  or 
from  complete  ring  synechise  (p.  175)  in  cases  complicated  with 
iritis — may  become  a  second  factor  in  the  process. 

These  ectasies  or  staphylomata   are  of  a  bluish-black  colour, 

owing  to  the  uvea,  or  the  atro- 
phied   remains     of     it,     shining 

through  the  thin  layer  of  sclerotic. 

The  staphylomata  occupy  either 

the  equator  of  the   eyeball  near 

the    insertions     of    the    muscles 

(equatorial  staphyloma),  or  they 

are  situated  in  the  portion  of  the 

sclerotic    close     to    the    cornea, 

where  it  is  lined  by  the    ciliary 

body  (anterior  or  ciliary  staphy- 
loma) (Fig.  70).     The  former  can 

be  observed  only  when  the  eye  is 

turned  well  over  to  the  opposite 

side.     The  anterior  staphylomata 

may    also  be  single   or  multiple, 

and  in  the  latter  case  they  may  become   confluent  and  extend  all 


Fig.  70. — Anterior  or  ciliary 
staphyloma  of  the  sclerotic.  Cup- 
ping of  the  optic  disc  due  to  high 
tension. 


172  DISEASES   OF   THE  EYE.  [chap.  vi. 

round  the  cornea.  A  variety  of  the  anterior  staphyloma  is  termed 
intercalary  staphyloma,  to  indicate  that  it  has  its  origin  in  the 
narrow  space  between  the  ciliary  body  and  the  root  of  the  iris. 

Treatment. — For  equatorial  and  anterior  staphyloma,  if  the 
tension  of  the  eye  be  high,  an  iridectomy,  if  it  can  be  performed, 
is  indicated,  and  by  means  of  it  the  progress  of  the  distension  may 
be  arrested,  and  vision  preserved.  Should  an  iridectomy  be  im- 
practicable, excision  of  the  eyeball  will  often  have  to  be  advised  for 
the  relief  of  pain,  which  is  sometimes  present,  or  to  get  rid  of  the 
inconvenience  caused  by  the  large  size  of  the  eyeball,  or  on  aesthetic 
grounds. 

Congenital  Defects  of  the  Sclerotic.  Coloboma. — This  forms  an  ectasy 
of  the  sclerotic  commencing  below  the  posterior  pole  of  the  eye,  and 
extending  forwards  towards  the  ciliary  region.  It  is  accompanied  by 
coloboma  of  the  chorioid,  and  sometimes  of  the  iris  and  lens  as  well,  and 
is  due  to  imperfect  closure  of  the  chorioidal  fissure. 

Blue  Sclerotics. — In  this  condition,  which  is  hereditary,  and  has  been 
met  with  in  four  generations,  a  light  blue  (azure)  discoloration  of  the 
sclerotic  is  frequently  associated  with  fragilitas  ossium.  Inherited 
syphilis  was  present  in  some  of  the  cases. 


CHAPTER   VII. 
DISEASES    OF    THE   UVEAL   TRACT. 

Inflammations. 

The  iris,  ciliary  body,  and  cliorioid  ^  together  form  the  uveal  tract. 
If  it  be  remembered  that  they  closely  resemble  each  other  histologi- 
cally, that  their  blood  supply  is  identical,  and  that  they  form  with 
each  other  a  continuous  membrane,  it  is  a  matter  of  surprise  that  any 
one  of  these  three  divisions  of  the  uveal  tract  can  undergo  inflamma- 
tion while  the  others  remain  healthy.  Yet  this  is  by  no  means 
uncommonly  the  case.  But  it  is  more  common  for  at  least  two  of 
them,  and  especially  the  iris  and  ciliary  body,  to  be  simultaneously 
inflamed  {irido-cyclitis)  ;  and  the  entire  uveal  tract  may  be  affected 
at  one  time  {irido-chorioiditis — by  which  term  it  is  implied,  not  only 
that  the  iris  and  the  chorioid  are  diseased,  but  also  the  intervening 
portion  of  the  tract,  the  ciliary  body).  If  all  three  portions  be 
affected,  one  of  them  may  be  much  more  affected  than  either  of  the 
others.  Or,  commencing  in  one  portion,  the  inflammatory  process 
often  spreads  to  one  or  both  of  the  other  portions. 

It  is  convenient,  in  a  systematic  consideration  of  inflammation 
of  the  uveal  tract,  to  discuss  it  under  the  separate  headings  of  iritis, 
cyclitis,  and  chorioiditis. 

Inflammation  of  the  Iris.  Iritis. — Iritis  is  acute  or  chronic. 
It  may  also  be  primary  or  secondary.  In  primary  iritis,  the  in- 
flammation begins  in  the  iris  itself,  and  is  not  a  result  of  some  other 
diseased  process  in  the  eye.  Secondary  iritis  may  be  caused  by 
disease  of  the  cornea  or  sclerotic,  or  by  the  swelling  of  an  injured 
lens,  the  presence  of  an  intra-ocular  tumour,  detached  retina,  etc. 

Acute  Iritis. — The  Objective  Signs  of  Acute  Primary  Iritis,  more 
or  less  marked  according  to  the  severity  of  the  case,  are  : — {a)  loss 

^  XopioVf  the  chorion  ;  hence  chorioid,  like  the  chorion. 
173 


174  DISEASES   OF   THE  EYE.  [chap.  vil. 

of  lustre  and  of  distinctness  of  pattern  of  the  iris  ;  (b)  change  in 
colour  of  the  iris  ;  (c)  functional  disturbances  (impaired  mobility) 
of  the  iris  ;  (d)  contraction  of  the  pupil ;  [e)  circumcorneal  injection 
of  the  ciliary  vessels. 

(a)  The  loss  of  lustre  and  of  distinctness  of  pattern  is  due  to 
exudation  in  the  substance  of  the  iris  and  on  its  surface,  and  to 
cloudiness  of  the  aqueous  humour  through  which  the  iris  is  seen — 
caused  by  inflammatory  products  held  in  suspension — and  often, 
also,  to  some  cloudiness  of  the  cornea,  (b)  The  change  in  colour 
is  due  to  hyperaemia  of  the  iris,  as  well  as  to  the  presence  of  the 
inflammatory  products ;  a  blue  iris  becomes  greenish,  a  brown  iris 
yellowish,  (c)  The  impaired  mobility,  and  the  {d)  contracted  pupil, 
are  due  to  hyper?emia,  to  spasm  of  the  sphincter  iridis,  and  to 
posterior  synechiae.  (e)  The  circumcorneal,  or  ciHary,  injection 
(Plate  II.  Fig.  2)  is  due  to  engorgement  of  the  episcleral  branches  of 
the  anterior  ciliary  arteries  which  supply  the  iris. 

Exudation  of  inflammatory  products  is  present,  in  greater  or  less 
degree,  on  either  surface  of  the  iris,  and  in  its  stroma  ;  in  the  pupil, 
or  rather  on  the  anterior  capsule  of  the  lens  in  the  pupillary  area, 
and — when,  as  so  often  happens,  cyclitis  is  associated  with  iritis — in 
the  aqueous  humour,  and  on  the  posterior  surface  of  the  cornea. 
As  a  consequence  of  the  exudation  in  and  on  the  iris,  in  addition  to 
change  in  colour,  and  loss  of  pattern,  the  iris  is  often  slightly 
swollen. 

Posterior  synechise  ^ — i.e.  adhesions  between  the  iris  and  the 
anterior  capsule  of  the  lens  (Plate  II.  Fig.  2) — occur  as  a  result 
of  inflammatory  exudation  on  the  posterior  surface  of  the  iris,  or 
on  its  pupillary  margin.  The  presence  of  posterior  synechise  is 
ascertained  by  observing  the  play  of  the  pupil  when  the  eye  is 
placed  alternately  in  strong  light  and  in  deep  shadow,  or  by 
observing  the  effect  of  a  drop  of  atropine  solution  on  the  pupil,  the 
latter  dilating  only  at  those  places  where  there  are  no  synechise. 
The  pupillary  margin  may  be  adherent  at  one  or  two  points  only  ; 
or  there  may  be  broad  synechiae  occupying  at  least  a  fourth,  or  a 
third,  or  even  more  of  the  margin  of  the  pupil ;  or  there  may  be 
both  small  and  broad  synechiae  present ;  or,  finally,  the  entire 
margin  of  the  pupil  may  be  adherent.     If  the  entire  pupillary  margin 

^  crovex^Xv,  to  hind  together. 


CHAP,  vii.l  THE    UVEAL   TRACT.  175 

have  become  adherent,  the  condition  is  termed  complete  posterior 
synechia  (or  circular  posterior  synechia,  ring  synechia,  or  exclusion 
of  the  pupil)  ;  and  in  such  cases,  especially  if  of  some  standing, 
atropine  has  no  effect  on  the  pupil.  When  complete  posterior 
synechia  has  developed,  the  iris  after  a  time  becomes  bulged  for- 
wards like  the  sail  of  a  ship  in  the  wind,  by  reason  of  accumulation 
behind  it  of  aqueous  humour,  which  now  cannot  escape  into  the 
anterior  chamber,  and  this  condition  is  known  as  iris  bombe  ;  it 
is  very  liable  to  cause  high  tension  of  the  eye  (Secondary  Glaucoma). 

If  the  area  of  the  pupil  be  filled  with  exudation — lying  on  the 
anterior  capsule  of  the  lens — circular  synechia  being  usually  also 
present,  the  condition  is  known  as  occlusion  of  the  pupil. 

Total  posterior  synechia  is  that  condition  in  which  the  whole 
posterior  surface  of  the  iris  is  adherent  to  the  capsule  of  the  lens. 
It  is  rarely  the  result  of  ordinary  iritis,  but  is  seen  frequently  in 
sympathetic  ophthalmitis. 

Exudation  of  inflammatory  products  into  the  anterior  chamber 
causes  turbidity  of  the  aqueous  humour,  and  sometimes  these 
products  sink  to  the  bottom  of  the  chamber  and  form  a  pseudo- 
hypopyon.  In  some  rare  cases,  the  exudation  in  the  anterior 
chamber  takes  the  form  of  a  jelly-like  mass,  which  may  resemble 
a  dislocated  crystalline  lens.  On  the  posterior  surface  of  the  cornea, 
in  some  instances,  exudation  fastens  itself  as  punctate  deposits 
(so-called  keratitis  punctata),  and  these,  and  turbidity  of  the  aqueous 
humour,  indicate  that  the  ciliary  processes  are  involved  in  the 
inflammation. 

The  Subjective  Symftoms  of  Acute  Primary  Iritis  are  : — {a)  pain, 
(6)  lacrimation  and  photophobia,  (c)  and  dimness  of  vision,  {a)  The 
pain  is  due  to  irritation  of  the  ciliary  nerves  in  the  inflamed  part. 
Yet  this  pain  is  not  always  so  much  in  the  eye  itself,  as  in  the  brow 
over  it,  in  the  corresponding  side  of  the  nose,  and  in  the  malar 
bone,  and  may  extend  to  the  whole  side  of  the  head.  It  varies  in 
its  intensity  and  is  often  more  severe  at  night.  Some  forms  of 
iritis  are  usually  attended  by  much  pain,  while  others  are  free  from 
it.  (6)  The  lacrimation  and  photophobia  are  reflex  effects  from 
irritation  of  the  fifth  nerve,  they  are  often  absent,  and  are  rarely 
present  to  such  a  degree  as  in  some  corneal  affections,  (c)  The 
dimness  of  vision  is  due  to  one  or  other  or  to  all  of  the  following  : — ■ 
turbidity  of  the  aqueous  humour,  punctate  deposits  on  the  posterior 


176  DISEASES   OF   THE  EYE.  [chap.  vlt. 

surface  of  the  cornea,  exudation  of  lymph  on  the  pupillary  area  of 
the  anterior  capsule  of  the  lens,  opacities  in  the  vitreous  humour. 

A  gTave  mistake  into  which  beginners  often  fall  is  to  take  a  case 
of  iritis  to  be  one  of  conjunctivitis  or  scleritis  (see  pp.  46  and  164), 
the  "  redness  of  the  white  of  the  eye  "  being  that  which  misleads. 
The  appearance  of  the  iris  itself — normal,  or  exhibiting  the  signs 
of  iritis — will  chiefly  assist  in  the  diagnosis.  Moreover,  the  pain 
in  iritis  is  of  neuralgic  character,  but  in  conjunctivitis,  if  there 
be  any  pain,  it  is  similar  to  that  caused  by  a  foreign  body  in  the 
conjunctival  sac.  In  iritis  there  is  no  discharge,  while  in  conjunc- 
tivitis the  eyelids  are  gummed  in  the  morning  by  muco-purulent 
secretion.  The  vascular  injection  in  iritis  is  of  the  pericorneal 
ciliary  vessels,  but  in  conjunctivitis  of  the  conjunctival  vessels 
(Plate  II.).  In  iritis,  however,  it  often  happens  that  there  is  con- 
junctival as  well  as  ciliary  injection.  But,  as  already  stated,  the 
appearance  of  the  iris  itself  is  the  most  valuable  guide  in  the  diagnosis. 
Look  at  the  iris.  If  the  opposite  eye  be  healthy,  compare  the  iris  in 
the  affected  eye  tvith  that  in  the  healthy  eye.  These  are  important 
precepts  in  the  diagnosis  of  iritis. 

Clinically  we  cannot  always  know  whether  only  one  or  more  than 
one  division  of  the  uveal  tract  is  in  a  state  of  inflammation.  This 
uncertainty  is  particularly  liable  to  arise  when  there  is  severe  .acute 
iritis  ;  for  then  the  symptoms  present  might  all  be  derived  from  the 
inflammation  of  the  iris  alone,  while  the  contracted  and  obscured 
pupil,  opacity  in  the  aqueous  humour  and  cornea,  and  irritability 
of  the  eye,  render  impossible  a  diagnosis  of  chorioiditis  by  the 
ophthalmoscope  ;  and,  whether  in  health  or  disease,  the  position  of 
the  ciliary  body  puts  it  always  out  of  reach  of  ophthalmoscopic 
examination.  Yet  it  may  be  taken  for  granted,  that  in  every 
severe  case  of  iritis,  particularly  in  those  of  syphilitic  origin,  more  or 
less  cyclitis  is  also  present ;  while  a  deep  anterior  chamber,  diminished 
tension,  tenderness  on  pressure,  or  punctate  deposits  on  the  posterior 
surface  of  the  cornea  increase  the  suspicion.  In  most  cases  of  very 
slight  iritis  there  is  probably  no  cyclitis. 

It  is  only  after  the  acute  inflammatory  symptoms  have  subsided, 
and  the  pupil  has  become  clear,  that  disseminated  changes  in  the 
chorioid,  opacities  in  the  vitreous  humour,  and  even  retinitis  and 
optic  neuritis,  which  may  lead  to  optic  atrophy,  can  be  discovered, 
with  their  corresponding  depreciation  of  vision. 


CHAP,  vii.i  THE    UVEAL   TRAC1\  177 

Etiology  of  Acute  Primary  Iritis. — The  most  common  cause  by 
far  of  acute  primary  iritis  is  syphilis,  pro])al)ly  50  per  cent,  of 
the  cases  being  due  to  it.  Other  causes  are  gonorrhoea,  tubercle, 
rheumatism,  diabetes,  enteric  fever,  pneumonia,  influenza. 

Syphilitic  Iritis. — It  is  usually  in  the  secondary  stage  of 
acquired  syphilis,  along  with,  or  following  on,  the  papular  skin 
eruption,  that  one  sees  iritis  ;  and,  in  the  majority  of  cases,  there 
is  no  characteristic  appearance  to  indicate  its  specific  nature,  this 
diagnosis  depending  upon  the  general  history,  or  on  the  presence 
of  other  signs  of  syphilis.  The  plastic  inflammatory  exudation 
is  present  mainly  on  the  surface  of  the  iris,  and  along  the  pupillary 
margin,  and  often  also  in  the  pupil.  Posterior  synechiae  always 
form,  and  it  is  occasionally  in  these  cases  that  the  gelatinous  exuda- 
tion in  the  anterior  chambers  mentioned  above  is  seen.  The  cir- 
cumcorneal  injection  is  generally  well  marked,  sometimes  causing 
elevation  of  the  limbus  of  the  conjunctiva,  and  even  general, 
although  slight,  chemosis.  The  degree  of  irritation  (pain,  photo- 
phobia, and  lacrimation)  varies  considerably,  and  is  often  slight, 
even  where  the  appearances  in  the  iris  are  well  marked. 

Late  in  the  secondary  stage  of  syphilis,  or  within  a  year  or  so 
after  the  primary  infection,  a  form  of  iritis  may  occur  which  can, 
indeed,  be  recognised  as  syphilitic.  It  is  characterised  by  the  forma- 
tion of  circumscribed  nodules,  or  small  condylomata,  of  a  yellowish- 
red  colour,  the  rest  of  the  iris  being  apparently  intact  (Plate  II. 
Fig.  2).  These  nodules  vary  in  size  from  that  of  a  hemp-seed  to 
that  of  a  small  pea,  and  are  situated  usually  at  the  pupillary  margin, 
occasionally  at  the  periphery  of  the  iris,  and  very  rarely  in  the  body 
of  the  iris.  There  may  be  but  one  nodule  present,  and  there  are 
seldom  more  than  three  or  four.     This  form  is  not  common. 

Occasionally  iritis  occurs  in  the  tertiary  stage  of  syphilis,  and 
then  sometimes  with  the  formation  of  inflammatory  tumours  in 
the  iris,  which  are  to  be  regarded  as  gummata. 

In  inherited  syphilis,  iritis  does  sometimes  occur  without  inter- 
stitial keratitis  (p.  137),  but  is  more  frequently  seen  in  conjunction 
with  the  latter.  Childhood  and  youth  are  the  periods  of  life  in 
which  it  is  observed.  In  doubtful  cases  Wasserman's  test  or  the 
Luetin  test  may  be  used. 

GoNORRHCEAL   Iritis. — This   is   not   uncommon,   and   probably 
many  cases  of  iritis  reckoned  as  rheumatic  are  in  fact  due  to  gonor- 
12 


178  Di:^EASES   OF    THE   EYE.  [chai\  vii. 

rhoea.  The  appearances  are  very  similar  to  those  of  the  iritis  which 
occurs  in  secondary  syphilis,  but  punctate  deposits  on  the  posterior 
surface  of  the  cornea  are  more  common  in  the  gonorrhoeal  cases. 
Iritis  does  not  attend  on,  nor  immediately  follow,  a  gonorrhoea  ; 
but  an  attack  of  gonorrhoeal  arthritis,  usually  of  the  knees,  always 
intervenes,  and  the  interval  between  the  attack  of  arthritis  and  the 
attack  of  iritis  may  be  very  lengthened — extending  even  to  years. 

Tubercular  Iritis. — Tubercle  occurs  in  the  iris  in  three  forms  ; 
of  these,  one,  the  conglomerate  or  solitary  tubercle  of  the  iris,  will 
be  described  under  the  heading  of  New  Growths  of  the  Iris.  It  is 
not  usually  associated  with  iritis.  The  other  forms  are  properly 
regarded  as  tubercular  iritis.     They  are  : — 

a.  Very  fine  miliary  nodules  which  occur  in  the  iris,  chiefly 
at  the  angle  of  the  anterior  chamber,  or  near  the  pupillary  margin, 
where  they  give  rise  to  posterior  synechise.  They  are  of  a  yellowish- 
grey  colour,  or,  by  reason  of  vessels  which  may  form  in  them,  they 
may  be  reddish,  or  cinnamon  coloured.  There  is  some  iritis,  and 
often,  also,  punctate  deposits  on  the  back  of  the  cornea  indicating 
engagement  of  the  ciliary  body.  The  process  runs  a  sluggish  course, 
and  is  not  painful ;  the  nodules  increase  in  size  slowly,  then  cease  to 
grow,  become  smaller,  and  finally  disappear.  This  form  of  tubercular 
iritis  has  been  termed  by  Leber  attenuated  tuberculosis  of  the  iris, 
and  its  prognosis  is  favourable,  although  some  derangement  of  sight 
may  remain  as  a  result  of  the  iritis.     The  disease  is  often  binocular. 

h.  The  second,  and  more  common,  form  of  disseminated  tuber- 
culosis of  the  iris  is  also  associated  with  iritis,  accompanied  with 
much  ciliary  injection.  But  in  this  form,  along  with  small  nodules, 
there  are  some  of  larger  size — so  large,  sometimes,  as  to  touch  the 
back  of  the  cornea.  They  are  of  a  pale  buff  colour,  and  may  be 
scattered  over  the  whole  iris,  although  their  seat  of  election — a 
rather  important  point  for  the  diagnosis — is  the  angle  of  the  anterior 
chamber.  This  form  is  frequently,  and  in  our  experience  commonly, 
associated  with  tubercular  disease  of  the  true  cornea  (tubercular 
kerato-iritis),  which  is  manifested  by  a  diffuse  haze  in  the  deep 
layers  of  the  cornea,  and  by  the  presence,  in  the  same  layers,  of 
scattered  small  and  large  greyish-yellow  infiltrations,  each  of  them 
surrounded  by  a  less  intense  halo.  A  vascular  network,  derived 
from  the  deep  marginal  vessels,  forms  about  these  corneal  infiltrations. 
Punctate  deposits  are  present  on  the  back  of  the  cornea,  and  the 


CHAP.  VII.]  THE    UVEAL    TRACT.  179 

aqueous  humour  may  be  hazy  ;  and  if  the  vitreous  humour  can  be 
examined,  it,  too,  may  be  found  more  or  less  opaque.  This  form 
usually  goes  on  to  complete  loss  of  sight  if  untreated.  At  a  late 
period,  the  growth  of  tubercle  ceases,  and  the  shape  of  the  eyeball, 
with  more  or  less  opaque  cornea,  may  be  retained ;  or  caseation, 
followed  by  phthisis  bulbi,  may  result.  One  or  both  eyes  may  be 
attacked.  Pain  is  not  a  prominent  symptom — in  many  cases  there 
is  none. 

The  diagnosis  of  tuberculosis  of  the  iris  cannot  be  made  off-hand 
from  the  presence  of  nodules  in  the  iris,  as  nodules  occur  in  other 
forms  of  iritis,  notably  in  some  cases  of  syphilitic  iritis.  The 
syphilitic  condyloma  is  of  a  yellowish-red,  while  the  tubercular 
nodule  is  of  a  greyish-red  or  of  a  buff  colour,  and  often  presents  a 
somewhat  translucent  appearance.  Those  cases  of  nodular  iritis  which 
are  accompanied  by  infiltrations  in  the  deep  layers  of  the  cornea,  as 
above  described,  can  be  regarded  with  great  certainty  as  tubercular. 
But  the  history  of  the  patient— exclusion  of  syphilis,  acquired  or 
congenital — his  present  state  as  regards  tubercle  elsewhere  in  the 
system,  and  the  family  history  as  to  tubercle  must  be  investigated. 
As  tubercle  of  the  iris  commonly  occurs  in  childhood  or  in  early 
youth,  the  exclusion  of  acquired  syphilis  is  not  often  difficult,  and 
the  presence  or  absence  of  the  stigmata  of  congenital  syphilis  decides 
the  diagnosis  in  that  respect.  In  leprosy,  leucaemia,  and  in  pseudo- 
leucaemia,  iritis  with  formation  of  nodules  occurs,  and  also  in  those 
rare  conditions  ophthalmia  nodosa  (p.  86)  and  sporotrichosis. 

Signs  of  former,  or  of  existing,  tubercular  disease  elsewhere  in  the 
body  are  obviously  of  great  value  for  the  diagnosis,  for  intra-ocular 
tuberculosis  is  alw^ays  a  secondary  or  metastatic  condition,  the 
primary  focus  being  elsewhere  in  the  system.  Should  no  such  focus 
be  found,  it  must  be  remembered  that  it  is  possible  for  a  small 
tubercular  deposit  to  be  present  in  the  body,  which  may  cause  no 
symptom,  and  w^hich  may  escape  detection  by  physical  examination  ; 
in  short,  intra-ocular  tuberculosis,  although  not  the  primary  focus, 
may  be  the  first  indication  of  tubercular  infection. 

The  microscopical  examination  of  a  portion  of  the  iris  removed 
by  iridectomy  is  conclusive  for  the  diagnosis,  if  tubercle  bacilli  can 
be  found  in  it,  but  this  is  rarely  so.  An  inoculation  experiment,  by 
the  insertion  of  a  portion  of  the  iris  into  the  anterior  chamber  of 
a  guinea-pig's  eye,  gives  a  more  certain  result.     Neither  of  these 


180  DISEASES    OF    THE   EYE.  [chap.  vii. 

measures,  however,  is  admissible,  as  iridectomy  is  liable  to  cause 
the  iritis  to  take  on  renewed  activity.  The  aqueous  humour  may 
be  drawn  off  with  a  fine  hypodermic  syringe,  and  injected  into  the 
anterior  chamber  of  a  guinea-pig's  eye,  where  it  gives  rise  to  tuber- 
cular iritis  if  tubercle  bacilli  be  present,  which  is  not  always  the 
case.     This  proceeding  is  harmless. 

Finally,  for  diagnostic  purposes  a  hypodermic  injection  of 
tuberculin  may  be  used.  Of  Koch's  old  tuberculin  a  dose  of  1  m.gr. 
of  the  dry  substance  is  injected.  If  the  disease  be  tubercular,  a 
sudden  and  decided  rise  of  temperature  may  take  place,  and  as 
rapidly  subside  ;  and  occasionally  there  is  a  passing  local  reaction 
in  the  eye.  If  there  be  no  increase  of  temperature,  a  double  dose 
is  giv^n  the  next  day  but  one.  But  if  there  have  been  a  slight 
elevation  of  temperature,  even  if  it  be  only  J  degree,  the  dose  is  not 
increased,  and  after  the  temperature  has  again  become  quite  normal, 
the  same  dose  is  repeated.  It  will  often  be  noted  that  the  second 
reaction  which  now  occurs — although  the  dose  is  the  same — is  more 
marked  than  the  first.  This,  in  Koch's  opinion,  is  an  exceedingly 
characteristic  occurrence,  and  may  be  taken  as  an  unfailing  sign  of 
the  presence  of  tuberculosis.  But  if  no  reaction  follows  on  the  low 
doses,  then  a  dose  of  5  m.gr.  and  finally,  if  necessary,  one  of  10  m.gr. 
is  given,  or,  to  make  quite  sure,  this  last  dose  may  be  repeated.  If 
then  there  be  no  reaction,  the  presence  of  tubercle  may  be  excluded. 
The  reaction  may  be  looked  for  in  from  twelve  to  eighteen  hours 
after  the  injection.  This  method  is  the  one  we  employ.  Von 
Pirquet's  Cuti-Eeaction  may  be  employed. 

Rheumatic  Iritis. — This  is  usually  of  the  form  which  is  common 
in  the  early  secondary  stage  of  syphilis  (p.  177),  but  it  is  accom- 
panied by  circumcoxneal  injection,  which  is  great  in  proportion  to 
the  other  signs  of  iritis  present.  The  pain  is  often  peculiarly  severe, 
and  again  the  attack  may  be  painless.  Iritis  is  not  found  in  associa- 
tion with  acute  rheumatic  arthritis,  but  rather  with  the  sub-acute 
articular  rheumatism,  which  attacks  now  one  joint  and  again  another 
through  several  months  of  the  year,  in  the  winter  and  spring.  Rheu- 
matic iritis  is  very  liable  to  recur. 

Treatment  of  Acute  Primary  Iritis. — A  mydriatic  is  in  all  cases 
the  most  important  means.  Most  commonly  a  solution  of  atropine 
(Atrop.  sulph.  gr.  iv.,  Aq.  dest.  §j)  is  used  as  eye-drops.  An  atom  of 
sulphate  of  atropine  in  substance,  placed  in  the  conjunctival  sac, 


CHAP,  vir.]  THE    UVEAL    TRACT.  181 

gives  a  very  pronounced  reaction.  It  is  also  used  in  the  form  of 
ointment  (Atrop.  sulph.  gr.  iv.,  vaselin  §j),  and  in  gelatine  discs. 

By  paralysing  the  sphincter  iridis,  atropine  provides  rest  for  the 
inflamed  iris  ;  and,  if  adhesions  have  already  formed,  the  dilatation 
of  the  pupil  may  break  them  down,  while  if  none  be  as  yet  present, 
the  dilatation  will  greatly  aid  in  preventing  their  formation.  Again, 
owing  to  diminished  volume  of  the  iris,  its  vessels  contain  less  blood, 
and  the  hyperasmia  of  the  inflamed  part  is  reduced.  Yet  in  cases 
of  irido-cyclitis,  where  the  cyclitis  is  the  prominent  factor,  atropine 
does  not  always  promote  the  cure,  for  by  depleting  the  vessels  of  the 
iris  it  engorges  those  of  the  ciliary  body. 

To  produce  a  maximum  effect  on  the  pupil,  where  it  is  desired 
to  break  down  adhesions,  six  drops  of  the  atropine  solution  should 
be  instilled  into  the  eye,  with  an  interval  of  from  five  to  ten  minutes 
between  each  ;  and  in  this  way  the  atropine  from  each  drop  has  time 
to  make  its  way  into  the  anterior  chamber,  and  finally  the  accumu- 
lated effect  of  all  six  is  obtained.  More  than  one  drop  can  hardly  be 
retained  in  the  conjunctival  sac  at  a  time.  The  use  of  cocaine 
(2  per  cent.)  along  with  atropine  ensures  a  maximum  dilatation.  A 
drop  of  the  atropine  solution  into  the  eye  from  once  or  twice  to  four 
times  a  day  is  required,  in  order  to  maintain  the  desired  dilatation 
of  the  pupil  ad  maximum,  in  a  severe  case. 

Some  individuals  are  peculiarly  susceptible  to  atropine  poisoning, 
of  which  the  symptoms  are  : — dryness  of  the  throat,  fever,  fullness 
in  the  head,  headache,  delirium,  coma.  The  antidote  is  morphia,  of 
which  J  grain  used  hypodermically  neutralises  -Jg-  grain  of  atropine 
in  the  system.  Atropine  poisoning  can  occur  by  the  introduction 
of  the  solution  into  the  stomach  through  the  lacrimal  canaliculi, 
nose,  and  fauces  ;  and  to  prevent  this  the  finger  of  the  patient  may 
be  placed  in  the  inner  canthus,  so  as  to  occlude  both  canaliculi  during, 
and  for  some  moments  after,  the  introduction  of  the  drop  into 
the  eye. 

After  use  of  atropine  in  some  persons  the  skin  of  the  lower  eyelid, 
or  of  both  eyelids,  becomes  eczematous,  red,  swollen,  and  painful ; 
and  in  other  cases  after  long  use  follicular  conjunctivitis  is  induced. 
If  these  complications  occur,  solution  of  scopolamine  should  be 
substituted  for  atropine,  and  suitable  remedies  used  for  skin  or  con- 
junctiva. Scopolamine  solutions  should  not  be  stronger  than  J  to  J 
per    cent.      We    have  seen  very  marked  symptoms  of  poisoning 


182  DISEASES   OF   THE   EYE.  [chap.  vii. 

follow  the  use  of  a  1  per  cent  solution,  which  was  not  prescribed 
by  us. 

In  old  people  tenesmus  and  retention  of  urine  sometimes  result 
from  use  of  atropine. 

Atropine,  while  it  is  so  useful  in  the  treatment  of  inflammations 
of  the  iris,  ciliary  body,  and  cornea,  is  of  no  benefit  in  many  other 
diseases  of  the  eye,  and  is  positively  harmful  in  some  of  them.  It 
is  necessary  to  make  this  statement  very  explicitly,  for  many  medical 
men,  who  have  not  devoted  attention  to  the  subject  of  eye-disease, 
include  atropine  in  every  eye-lotion  they  prescribe.  If  the  disease 
prescribed  for  be  conjunctivitis,  the  atropine  is  calculated  rather  to 
increase  than  to  relieve  the  conjunctival  affection  ;  while,  if  the 
patient  be  advanced  in  life,  there  is  always  the  danger  that  a 
tendency  to  glaucoma  may  be  present,  and  in  such  a  case  the 
dilatation  of  the  pupil  caused  by  the  atropine  will  be  sufficient  to 
bring  on  an  attack  of  acute  glaucoma.  It  falls  to  the  lot  of  most 
ophthalmic  surgeons  to  be  called,  at  one  time  or  another,  to  a 
case  of  acute  glaucoma  caused  by  the  use  of  atropine  in  this 
thoughtless  manner. 

Dark  protection  spectacles  should  be  worn  by  patients  suffering 
from  iritis  ;  and  in  severe  cases,  especially  in  cold  weather,  the  eye 
should  be  covered  with  a  thick  pad  of  cotton  wool,  and  the  patients 
should  be  confined  to  a  dark  room,  and  even  to  bed. 

Hot  fomentations — every  two  hours  for  twenty  minutes — are  of 
benefit  in  all  forms  of  acute  iritis,  and  they  relieve  pain.  Dionine  is 
also  useful  in  relieving  pain,  and  seems  to  promote  the  cure.  If  the 
pain  be  severe  at  night  a  hypodermic  injection  of  morphia  may  be 
given.  Should  there  be  much  irritation,  pericorneal  injection,  or 
chemosis,  leeching  at  the  external  canthus  over  the  orbital  margin 
is  of  use.  Occasional  gentle  purgatives  are  desirable.  Blistering 
on  the  temples,  or  behind  the  ear,  has  been  a  favourite  item  in  the 
treatment  of  iritis  ;  it  adds  to  the  annoyance  of  the  patient,  and 
as  a  remedy  it  is  valueless. 

In  addition  to  the  foregoing  measures  which  are  applicable  in 
all  cases,  the  special  etiological  moment  must  be  considered  in  the 
treatment  of  each  case,  as  follows  : — 

Treatment  of  Syphilitic  Iritis. — As  it  is  important  to  obtain  rapid 
absorption  of  the  inflammatory  products  so  abundantly  thrown  out, 
and  which  would  soon  cause  extensive  damage  to  the  eye,  the  system 


CHAP.  VII.]  THE    UVEAL    TRACT.  183 

should  be  put  under  the  influence  of  mercury  as  quickly  as  possible, 
by  the  use  of  mercurial  inunctions  ;  or  by  small  doses  of  calomel 
internally ;  or  by  intra-muscular  injections,  1  grain  of  metallic 
mercury  being  injected  once  or  twice  a  week  in  the  form  of  a  cream 
made  with  lanolin  as  recommended  by  Lambkin.  The  reports 
published  of  the  effect  of  salvarsan  in  syphilitic  iritis  are  very 
favourable.  When  the  acute  symptoms  have  passed  away,  an 
after  treatment  with  iodide  of  potassium  should  be  employed.^ 
In  iritis  due  to  congenital  syphilis,  mercury  is  not  generally  in- 
dicated, but  the  syrup  of  the  iodide  of  iron,  and  a  general  tonic 
treatment  is  preferable.  In  cases  of  acquired  syphilis,  as  there  is  a 
marked  tendency  of  iritis  to  relapse,  it  is  important  that,  for  some 
weeks  after  the  acute  stage  has  passed,  the  pupil  should  be  kept 
under  the  influence  of  atropine,  the  eyes  protected  with  dark  glasses, 
and  the  internal  administration  of  iodide  of  potassium  continued. 

An  attack  of  syphilitic  iritis  may  last  from  two  to  eight  weeks, 
and  cases  which  seem  to  be  slight — i.e.  where  the  pupil  dilates  well 
and  rapidly  to  atropine,  and  where  but  little  lymph  is  thrown  out — 
sometimes  cause  disappointment  by  their  slow  recovery.  It  is 
possible  that  an  attack  of  iritis,  if  carefully  treated  from  the  begin- 
ning, may  leave  the  eye  in  as  healthy  a  condition  as  before,  but  it 
is  more  common,  in  spite  of  every  effort,  to  find  isolated  posterior 
synechise,  or  a  circular  synechia,  left  behind.  The  presence  of  a  few 
isolated  synechiae,  if  the  pupil  be  clear,  is  in  itself  harmless  to  sight ; 
but,  if  relapse  should  take  place,  and  fresh  adhesions  form,  a 
complete  posterior  synechia  (p.  175)  going  on  to  iris  bombe  may 
ultimately  be  established.  Complete  posterior  synechia  may  of 
course  result  from  the  first  and  only  attack  of  iritis. 

In  some  cases  of  iritis,  the  vitreous  humour  becomes  more  or 
less  opaque,  and  this  condition  does  not  always  disappear  as  the 
iritis  gets  well ;  indeed,  it  may  not  be  possible  to  ascertain  its 
presence  until  after  the  inflammatory  process  in  the  iris  has 
subsided.  In  these  cases  the  ciliary  body  has  participated  in  the 
inflammation,  although  there  may  have  been  no  punctate  deposits 
on  the  cornea.  Again,  there  may  have  been  some  chorioiditis  and 
retinitis  during  the  attack.     Great  and  permanent  deterioration  of 

1  Iodide  of  potassium  must  not  be  prescribed  in  conjunction  with 
treatment  by  injections  of  metallic  mercury. 


184  DISEASES    OF    THE   EYE.  [chap.  vii. 

vision  may  result  from  such  complications  ;  and  this  emphasises  the 
importance  of  a  cautious  prognosis  at  the  commencement. 

In  complete  posterior  synechia,  after  the  acute  iritis  has  sub- 
sided, an  iridectomy  is  indicated  to  restore  communication  between 
the  posterior  and  anterior  chambers.  For  the  treatment  of  opacities 
in  the  vitreous  humour  see  chap,  xi.,  and  of  syphilitic  chorio-retinitis 
see  chap.  xii. 

Treatment  of  Tubercular  Iritis. — Cases  of  attenuated  tuberculosis 
of  the  iris  simply  require  local  treatment  with  atropine,  hot  fomenta- 
tions, and  protection  spectacles. 

In  the  treatment  of  the  more  j^ronounced  form  of  tubercular 
iritis,  the  tubercular  infection  must  be  combated,  and  the  chief 
therapeutic  measure  of  value  for  this  purpose  is  inoculation  with 
tuberculin.  The  method  we  employ  at  the  Victoria  Hospital  is  as 
follows  : — 

The  preparation  used  is  Koch's  Tubercle  Bacilli  Emulsion. 
The  patient's  temperature  having  been  ascertained  to  be  normal,  a 
hypodermic  injection  of  1  c.c.  of  the  '  fifth  dilution,'  representing 
0*000005  m.g.  of  the  bacillary  substance,  is  given.  The  temperature 
is  taken  every  two  hours,  and  if  in  the  course  of  twenty-four  hours 
there  be  no  reaction,  an  injection  of  1  c.c.  of  the  '  fourth  dilution,' 
equal  to  0*00005  of  the  bacillary  substance,  is  given.  The  dose  is 
thus  gradually  increased  at  intervals  of  one  or  two  days,  unless  the 
temperature  be  raised,  until  the  original  liquid  is  reached,  1  c.c.  of 
which  contains  5  m.gr.  of  the  substance.  When  the  higher  doses  are 
given,  the  intervals  should  be  considerably  longer,  and  if,  after  any 
dose,  a  rise  of  temperature  of  0*5  of  a  degree  or  more  take  place,  the 
previous  dose  is  repeated,  and  an  increased  dose  is  not  given  until  a 
general  reaction  ceases  to  be  caused.  In  the  majority  of  cases  treated 
marked  improvement  became  apparent  within  a  few  weeks,  the 
nodules  in  the  iris  becoming  smaller  and  less  vascularised,  the  deep- 
seated  corneal  infiltrations  thinner,  the  punctate  deposits  fewer, 
and  the  eye  less  irritable  and  injected,  until  finally,  with  continued 
treatment,  all  tubercular  deposits  and  infection  disappeared,  leaving 
only  such  permanent  damage  to  the  eye  and  sight — due  to  corneal 
changes  and  pupillary  occlusion — as  may  be  proportional  to  the 
duration  and  severity  of  the  disease  before  treatment  took  effect. 
The  treatment  is  a  protracted  one,  as  long  as  six  months,  possibly, 
being  needed  to  effect  cure  in  a  severe  case. 


CHAP.  VII.]  THE    UVEAL    TRACT.  185 

Valuable  adjuncts  in  the  treatment  with  tuberculin  are  local 
hot  fomentations,  cod-liver  oil,  and  syrup  of  the  iodide  of  iron. 

On  the  question  as  to  whether  an  eye  which  is  disorganised  by 
intra-ocular  tuberculosis  beyond  hope  of  recovery  should  be  excised, 
opinions  are  divided.  Were  the  eye  the  primary  focus,  excision 
might  be  indicated  in  even  a  less  advanced  stage.  But  cases  are 
on  record  in  which,  soon  after  excision  of  a  tubercular  eyeball, 
death  from  tubercular  meningitis,  or  from  acute  miliary  tuberculosis, 
took  place  ;  and  which  were  therefore  suggestive  of  dissemination 
of  the  tubercle  as  direct  result  of  the  operation.  We  can  offer  no 
experience  of  our  own  in  this  connection,  but  it  would  seem  that 
there  is  a  risk  in  removing  the  eyeball  in  these  cases.  Where 
excision  is  not  undertaken,  extension  of  the  disease  to  the  optic 
nerve,  and  so  to  the  brain,  is  exceedingly  rare. 

For  Eheumatic  Iritis  the  general  treatment  is  the  same— salicy- 
late of  soda,  aspirin,  etc. — which  is  found  useful  for  rheumatic 
symptoms  in  other  parts  of  the  body. 

In  Gonorrhoeal  Iritis,  too,  treatment  with  salicylate  of  soda  is 
the  most  successful.  Gonococcal  vaccines  have  given  good  results 
in  the  hands  of  several  surgeons. 

Chronic  Iritis  or  Irido-Cyclitis.— In  the  mildest  cases  of  chronic 
iritis  the  only  objective  sign  may  be  the  presence  of  punctate  deposits 
on  Descemet's  membrane  (so  called  Keratitis  Punctata)  with  no 
visible  changes  in  the  iris.  This  was  formerly  called  Serous  Iritis, 
but  is  in  fact  a  cyclitis.  In  other  cases  posterior  synechia  occur  with 
or  without  corneal  deposits.  In  the  severer  cases,  the  stroma  of  the 
iris  is  distinctly  altered  as  regards  colour  and  pattern,  there  are 
abundant  deposits  on  the  back  of  the  cornea,  and  opacities  in  the 
vitreous  humour.  There  is  no  pericorneal  injection  in  chronic  iritis, 
or,  at  most,  it  is  slight,  occasional,  and  ephemeral. 

The  chief,  or  only,  subjective  symptom  in  chronic  iritis  is  defective 
vision,  and  this  it  is  which  brings  the  patient  for  advice  ;  for  there 
is  little  or  no  pain,  photophobia,  or  lacrimation.  On  examination, 
some  of  the  above-mentioned  objective  signs  are  found,  and  inquiry 
elicits  the  fact  that,  except  for  gradual  failure  of  sight,  the  patient 
has  had  little  trouble  beyond  an  occasional  '  cold '  in  the  eye— i.^. 
slight  ciliary  injection— which  lasted  a  few  hours,  or  a  day  or  so  at 
a  time,  in  the  course  of  preceding  years. 

The  slighter  cases  of  this  affection  which  are  confined  to  the 


186  DISEASES   OF    THE   EYE.  [chap.  vii. 


iris,  and  do  not  run  a  long  course,  may  not  cause  serious  loss  of  sight, 
but,  on  the  other  hand,  cases  which  begin  as  mild  ones  may,  after 
a  few  relapses,  become  converted  into  typically  severe  cases.  The 
more  severe  cases,  accompanied  by  cyclitis  and  punctate  deposits, 
are  liable  to  be  complicated  with  high  tension  (secondary  glaucoma), 
owing  to  blocking  of  the  angle  of  the  anterior  chamber  with 
exudation,  which  seriously  endangers  vision. 

In  the  severest  cases  the  whole  uveal  tract  is  involved,  and 
the  term  Chronic  Uveitis  becomes  applicable  to  the  condition. 
The  exudation  of  inflammatory  products  is  very  great,  with  the 
following  results  : — marked  punctate  deposits — giving  rise  to  paren- 
chymatous opacity  of  the  cornea — turbid  aqueous,  atrophy  of  the 
iris,  posterior  synechiae  going  on  to  exclusion  of  the  pupil,  often 
occlusion  of  the  pupil,  iris  bombe,  opacity  of  the  vitreous  humour, 
cataract,  atrophy  of  the  chorioid  and  retina,  high  tension  owing 
to  iris  bombe,  absolute  blindness,  staphyloma  of  the  globe — or, 
in  the  last  stages,  the  eye  may  become  phthisical  instead  of  staphy- 
lomatous.  In  some  few  cases  iris  bombe  may  not  come  on,  and 
complete  blindness  may  not  result,  rendering  the  prospect  of  a 
cataract  extraction  fairly  good. 

Pathogenesis. — Chronic  Iritis  and  Chronic  Uveitis  frequently 
occur,  or  rather  commence,  in  youth,  and  are  more  common  amongst 
females  than  males.  The  severe  cases  may  continue  intermittently 
for  many  years  before  complete  blindness  is  reached.  Syphilis 
is  not  often  a  cause  of  chronic  uveitis.  Tubercle  is  now  held  to  be 
the  cause  in  a  certain  proportion  of  the  cases,  and  it  is  necessary 
to  give  diagnostic  injections  of  tuberculin  to  decide  the  diagnosis 
(p.  180).  Very  strong  evidence  has  been  collected  of  late  which 
renders  it  tolerably  certain  that  many  of  these  cases  are  caused  by 
auto-infection  arising  from  oral,  intestinal,  or  genito-urinal  sepsis, 
and  more  rarely  from  septic  conditions  in  other  parts  (furuncles, 
etc.).  Treatment  by  autogenous  vaccines  have  in  many  cases  proved 
most  beneficial  and  in  some  have  produced  a  rapid  cure.  Affections 
of  the  teeth,  especially  pyorrhoea  alveolaris,  may  undoubtedly  act  as 
a  cause  of  chronic  iritis  ;  only  one  or  two  teeth  may  be  involved. 

As  an  evidence  of  auto-intoxication  from  intestinal  stasis  indi- 
canuria  has  been  considered  important  by  some  authors,  but  it  is 
only  one  of  the  signs  of  intestinal  putrefaction  and  it  cannot  be  relied 
upon  as  an  indication  of  auto-infection. 


CHAP.  VII.]  THE    UVEAL   TRACT.  187 

Another,  and  a  more  difficult  question,  which  cannot  be  discussed 
here,  is  as  to  whether  intestinal  auto-iutoxication,  not  due  to  micro- 
organisms, but  to  the  formation  of  poisons  from  faulty  metabolism, 
can  also  be  held  responsible  for  a  chronic  iritis. 

Treatment  of  Chronic  Iritis  and  of  Chronic  Uveitis. — In  addition 
to  the  usual  local  measures — atropine,  hot  fomentations,  dionine, 
protective  dressing — sub-conjunctival  saline  injections  (p.  120) 
are  indicated.  Paracentesis  of  the  anterior  chamber  (p.  118)  may 
also  be  used  with  advantage,  and  can  be  repeated  about  once  a 
week.  The  hyperaemia  of  the  uveal  tract,  which  immediately 
follows  the  operation,  promotes  the  access  of  anti-bodies  and  other 
healing  substances  to  the  diseased  membrane. 

If  the  disease  be  due  to  tubercle,  a  course  of  treatment  with 
tuberculin  (p.  184),  concurrently  with  the  above  local  treatment, 
is  indicated.  Or,  if 'auto-infection  be  the  cause,  its  source  must  be 
ascertained,  if  possible,  and  vaccines,  preferably  autogenous,  should 
be  tried.  The  organisms  most  commonly  concerned  are  the  strepto- 
and  staphylo-coccus  and  the  pneumococcus.  If  necessary  the 
f?eces  should  be  examined. 

Inflammation  of  the  Ciliary  Body  :  Qyaliiis,— Acute  CycUtis, 
as  has  been  stated,  attends  all  cases  of  severe  acute  primary  iritis, 
and  often  many  of  the  slighter  cases,  whatever  be  their  etiology, 
a  fact  which  has  been  demonstrated  by  pathological  examination. 
Yet,  very  frequently,  there  are  no  clinical  signs  of  its  presence,  or 
they  are  masked  by  those  of  the  iritis.  The  most  common  clinical 
sign  of  cyclitis  in  these  cases  is  fine  punctate  deposits — often  so 
fine  as  to  be  discernible  only  with  the  combined  focal  method,  or 
w4th  the  corneal  microscope — on  the  back  of  the  cornea,  with,  it 
may  be,  slight  turbidity  of  the  aqueous  humour,  and  occasionally 
the  formation  of  a  small  pseudo-hypopyon. 

Owing  to  gravitation,  these  deposits  are  usually  precipitated  on 
the  lower  quadrant  of  the  cornea  over  a  triangular  area,  the  base 
of  which  corresponds  with  the  lower  margin  of  the  cornea,  the 
apex  being  directed  towards  the  centre  of  the  cornea,  with  the  finer 
dots  near  the  apex.  The  triangular  shape  results  from  the  motions 
of  the  eyeball.  In  many  cases,  however,  nearly  the  whole  cornea  is 
more  or  less  affected.  Some  of  the  larger  spots  present  an  opaque 
yellowish-white  appearance  which  has  been  compared  to  the  '  mutton 
fat '  drops  which  are  found  floating  in  cold  mutton  gravy. 


188  DISEASES   OF    THE  EYE.  [chap.  vii. 

In  cases  where  the  punctate  corneal  deposits  continue  for  a 
length  of  time,  permanent  secondary  changes  in  the  true  cornea 
take  place — in  consequence  of  the  resulting  degeneration  of  the 
endothelium  on  the  posterior  corneal  surface — and  a  consequent 
triangular  opacity  at  the  lower  part  of  the  cornea  will  ever  after- 
wards indicate  the  nature  of  the  process  which  has  gone  before. 

But  cyclitis  is  sometimes  seen  without  iritis.  Its  signs,  in  a 
severe  case,  in  addition  to  those  above  mentioned,  are: — Marked 
circumcorneal  injection,  pain  on  pressure  of  the  ciliary  region, 
deep  anterior  chamber  owing  to  hyper-secretion  of  the  aqueous 
humour  or  to  retraction  of  the  root  of  the  iris,  and  oedema  of  the 
upper  lid.  There  is  danger  of  increase  of  the  intra-ocular  tension, 
owing  to  the  tendency  to  blocking  of  the  angle  of  the  anterior  chamber 
with  inflammatory  exudation. 

Cases  which  may  begin  as  cyclitis  soon  show  signs  of  iritis,  and 
follow  the  same  course  as  those  already  described  under  the  heading 
Chronic  Irido-Cyclitis. 

Syphilitic  Gumma  of  the  Ciliary  Body. — This  is  rare,  and  belongs 
to  the  tertiary  stage  of  syphiUs,  although  it  is  sometimes  seen  much 
earlier.  It  is  always  preceded  by  acute  irido-cyclitis  of  the  usual  plastic 
type.  It  appears  at  first  as  a  small  circumscribed  nodule  with  smooth 
round  surface  slightly  raised  over  the  surface  of  the  sclerotic  in  the  ciliary 
region.  It  sometimes  increases  in  size  very  rapidly — and  is  then  attended 
by  violent  iritis  and  mvich  pain — and  again  but  slowly.  It  may  attain 
the  size  of  a  pea,  or  even  of  an  almond,  and  may  extend  some  way  around 
the  cornea,  presenting  a  reddish,  yellowish,  or  bluish  colour.  After  a 
time,  in  the  less  severe  cases,  the  gumma  becomes  smaller  and  disappears, 
leaving  a  dark  cicatrix  in  the  sclerotic.  But  in  other  cases  it  breaks 
through  the  sclerotic,  although  very  rarely  through  the  conjunctiva,  by 
destruction  of  tissue  ;  and  when  this  has  taken  place  the  tumour  grows 
smaller  and  undergoes  absorption,  and  the  eye  becomes  phthisical.  The 
gumma  may  also  grow  into  the  anterior  chamber,  and  but  rarely  into 
the  vitreous  humour.  The  interval  between  the  appearance  of  the  gumma 
and  completion  of  the  process  is  from  a  few  days  in  the  very  acute  cases, 
to  several  weeks  in  the  more  chronic  cases.  The  bulbar  conjunctiva  is 
hyperaemic,  and  often  chemotic.  In  the  cornea  there  is  generally  a  slight 
diffuse  opacity  with  stippling  of  the  epithelium,  and  there  may  be  posterior 
punctate  deposits. 

The  severe  acute  cases  are  accompanied  by  intense  interstitial  kera- 
titis, oedema  of  the  upper  lid,  and  violent  pain.  The  mildest  cases  may 
end  with  retention  of  fair  vision,  but  in  most  instances  serious  damage 
to  sight  results  ;  while,  in  very  many,  vision  is  totally  lost,  and  the  eye 
becomes  phthisical.  In  many  of  the  recorded  cases  the  eye  was  excised 
in  the  acute  inflammatory  stage  on  account  of  agonising  pain. 


Plate  III. 


L.W. 

Fig.  1.     Chorioido- Retinitis  (Specific). 


Fig.  2.     Disseminated  Chorioiditis. 


PLATE    III 

{To  face  page  189) 

Fig.  1. — Chorioido-Retinitis  in  an  early  stage.  A  central  area  of  haziness 
extends  around  the  disc  and  macular  region,  rendering  the  outline 
of  the  form  indistinct,  and  concealing  the  retinal  vessels  in  places. 
The  veins  are  somewhat  engorged.  Soft-edged  yellowish  white  spots 
of  chorioidal  exudation  are  visible  farther  out  towards  the  periphery. 
A  retinal  vein  passes  over  one  of  these  spots. 

Fio.  2. — Chorioido-Retinitis  in  a  later  stage.  The  retinal  haze  has  dis- 
appeared. Irregular  patches  of  atrophy  of  the  chorioid  are  scattered 
over  the  periphery,  some  of  them  bordered  by  pigment.  Spots  of 
black  pigment  surrounded  by  a  narrow  yellow  zone  are  also  to  be 
seen.  The  chorioidal  vessels  are  rendered  visible  close  to  the  disc, 
owing  to  atrophy  of  the  pigment-epithelium. 


onii 


CHAP.  VII.]  THE    UVEAL    TRACT.  189 

Tubercular  Cyclitis. — This  is  frequently  associated  with  tubercular 
iritis,  although  its  presence  cannot  be  clinically  detected.  Yet  in  some 
cases  the  disease  in  the  ciHary  body  assumes  the  form  of  a  large  nodule, 
or  even  a  tumour  of  considerable  size — or  there  may  be  more  than  one 
of  these — and  causes  staphylomatous  bulging  at  the  corneo-scleral  margin, 
which  may  go  on  to  rupture  externally. 

Treatment  of  Cyclitis. — This  follows  very  much  the  lines  of  the 
treatment  of  iritis.  Atropine,  by  paralysing  the  ciliary  muscle, 
acts  favourably  on  the  disease.  On  the  other  hand,  if  the  pupil 
be  dilatable,  atropine  causes  engorgement  of  the  ciliary  body  by 
the  blood  driven  out  of  the  iris.  Consequently,  its  effect  on  the 
symptoms  must  be  watched,  and  it  may  become  necessary  to  dispense 
with  its  use,  and  even  for  a  time  to  substitute  a  miotic.  Hot  fomen- 
tations to  the  eye,  and  a  warm  bandage,  and,  in  acute  cases,  leeching 
at  the  external  canthus  are  serviceable. 

In  chronic  cyclitis  sub-conjunctival  injections  of  normal  solution 
of  salt  are  indicated  ;  and,  if  the  intra-ocular  tension  become  high, 
paracentesis  of  the  anterior  chamber  should  be  performed. 

In  syphilitic  gumma  of  the  ciliary  body  an  active  mercurial 
treatment  is  necessary.  Salvarsan  is  very  efTectual.  In  tubercular 
disease,  treatment  with  tuberculin  affords  the  best  prospect  of  cure. 
*  Inflammations  of  the  Chorioid(xopioi/,  ^/iec/iomn,  hence  chorioid, 
like  the  chorion) .  Inflammations  of  the  chorioid  are  not  accompanied 
by  any  outward  signs  of  congestion,  or  by  pain  except  in  purulent 
cases,  and  hence  their  recognition  depends  on  ophthalmoscopic 
examination.  There  are  two  chief  forms  of  inflammation  of  the 
chorioid,  the  exudative,  which  is  subacute  or  chronic  and  appears  in 
discrete  patches  or  spots,  and  the  purulent,  which  is  acute  and  wide- 
spread and  generally  involves  the  retina  as  well. 

Both  forms  are  caused  by  micro-organisms,  or  possibly  by  their 
toxins,  circulating  in  the  blood.  Some  diseases  to  which  the  name 
of  chorioiditis  is  given  are  really  degenerative  affections.  The 
exudative  form  comprises  disseminated  chorioiditis,  central  chorioid- 
itis, syphilitic  and  tubercular  chorioiditis. 

Disseminated  Chorioiditis. — The  usual  Ophthalmoscopic  Ap- 
pearances of  this  disease  (Plate  III.  Fig.  2)  consist  either  in  round 
or  irregular  white  spots  or  patches  of  different  size  with  irregular 
black  margins,  or  in  small  spots  of  pigment,  these  changes  being 
surrounded  by  healthy  chorioidal  tissue  ;    or,  there  may  be  few  or 


190  DISEASES   OF    THE   EYE.  [chap.  vii. 

no  white  patches,  but  rather  spots  of  pigment  surrounded  by  a  pale 
margin.  The  retinal  vessels  are  seen  to  pass  over  the  patches. 
The  number  of  these  patches  or  spots  varies  according  to  the 
intensity  of  the  disease.  Their  position  is  at  first  at  the  periphery 
of  the  fundus  only,  but  later  on  they  appear  also  about  the 
posterior  pole  of  the  eye. 

These  appearances,  however,  represent  a  rather  late  stage  of 
the  disease,  the  early  stage  coming  but  rarely  under  observation. 
It  consists  in  small  circumscribed  plastic  exudations  into  the  tissue 
of  the  chorioid,  which,  if  seen  with  the  ophthalmoscope  (Plate  III. 
Fig.  1),  give  the  appearance  of  pale  pinkish-yellow  or  greyish 
spots  behind  the  retinal  vessels.  These  exudations  may  undergo 
absorption,  leaving  the  chorioid  in  a  fairly  healthy  state ;  but,  more 
usually,  they  give  rise  to  atrophic  cicatrices,  in  which  the  retina 
becomes  adherent,  with  proliferation  of  the  pigment-epithelium 
layer  in  their  neighbourhood,  and  hence  the  white  patches  with 
black  margins  above  described.  It  is  this  form  of  chorioiditis  which, 
in  its  earliest  stages,  is  often  associated  with  inflammatory  processes 
in  the  iris  or  ciliary  body,  either  as  a  primary  or  secondary  affection. 
But,  again,  in  many  instances  the  disease  does  not  extend  beyond 
the  chorioid. 

Sometimes,  in  addition  to  the  above  changes,  the  pigment- 
epithelium  layer  all  over  the  fundus  becomes  atrophied,  exposing 
to  view  the  vascular  network  of  the  chorioid,  while  here  and  there 
small  islands  of  pigment  are  present. 

Opacities  in  the  vitreous  humour  are  sometimes  found. 

Symftoms. — Diminution  in  the  visual  acuity,  especially  if  the 
macula  be  involved.  There  also  may  be  subjective  sensations  of 
light  or  colours,  positive  scotomata  (dark  areas  visible  to  the  patient), 
ring  scotomata  (Fig.  19)  or  sector-like  defects,  and  distortion  of 
objects  (metamorphopsia),  or  alteration  in  their  size  (megalopsia 
and  micropsia).     Night-blindness  is  not  uncommon. 

Causes. — Disseminated  chorioiditis  is  due  to  acquired  syphilis 
in  a  considerable  number  of  the  cases,  while  in  some  it  is  tuber- 
cular. But  in  a  very  large  proportion  of  cases  no  ascertainable 
cause  exists  ;  and  these  cases,  there  is  reason  to  suspect,  are  con- 
genital, and  probably  many  of  them  are  dependent  on  an  inherited 
syphilitic  taint.  In  eyes  with  congenital  cataract,  patches  of 
chorioiditis  are  often  found. 


CHAP.  VII.]  THE    WEAL    TRACT,  191 

Prognosis. — Disseminated  chorioiditis  is  always  a  serious  and 
very  chronic  disease,  fresh  spots  of  exudation  making  their  appear- 
ance from  time  to  time,  and  complete  recovery  cannot  be  looked  or. 
The  degree  of  defect  of  sight  it  may  cause  in  the  early  stages  depends 
much  on  the  extent  to  which  the  region  of  the  macula  lutea  has 
been  involved.  In  some  cases,  however,  fair  sight  may  be  retained 
for  many  years.  In  advanced  cases  the  optic  nerve  and  retina 
become  atrophied,  and  still  later  the  lens  becomes  cataractous. 

Treatment. — In  fresh  cases  due  to  acquired  syphilis,  a  prolonged 
but  mild  course  of  mercurial  inunctions  or  salvarsan  are  the  most 
suitable  measures,  to  be  followed  by  a  lengthened  course  of  treatment 
with  iodide  of  potassium.  Where  an  inherited  syphilitic  taint  is 
suspected,  iodide  of  iron  or  iodide  of  potassium  internally  may  be  of 
use.  Both  in  the  acquired  and  congenital  cases  salvarsan  will  be  of 
service.  If  tuberculosis  be  the  cause,  a  course  of  tuberculin  inocula- 
tions should  be  employed  ;  while,  in  the  cases  due  to  other  causes, 
small  doses  of  perchloride  of  mercury  may  be  given  ;  and  in  all 
cases  sub-conjunctival  injections  of  4  per  cent,  solution  of  common 
salt  are  indicated.  Dark  protection  spectacles  should  be  worn, 
and  absolute  rest  of  the  eyes  from  all  near  work  insisted  upon,  so 
long  as  the  disease  is  active. 

CENTRAii  Senile  Guttate  Chorioiditis. — This  is  a  degenerative 
disease  which  was  first  described  by  Waren  Tay.  It  consists  of  fine 
white,  pale  yellow,  or  glistening  dots,  best  seen  in  the  upright  image, 
and  situated  chiefly  about  the  macular  region,  or  between  this  and  the 
optic  papilla.  These  dots  are  due  to  colloid  degeneration  with  chalky 
formations  in  the  vitreous  layer  of  the  chorioid,  which  give  rise  to  secondary 
retinal  changes.  The  appearances  must  not  be  confounded,  as  they 
sometimes  have  been,  with  those  of  retinitis  punctata  albescens  (chap,  xii.), 
which  is  an  entirely  different  disease.  The  functions  of  the  retina  usually 
suffer  in  a  marked  manner,  so  that  a  partial  central  scotoma  may  be 
produced  ;  but  some  cases  have  been  observed,  in  which  vision  was  but 
little,  or  not  at  all,  affected. 

This  disease  attacks  both  eyes,  either  simultaneously  or  with  an 
interval,  and  is  most  often  seen  in  persons  of  advanced  life,  although  it  is 
also  found  in  middle  age,  and  even  in  youth. 

Treatment  is  of  no  avail. 

Central  Chorioiditis. — This  is  an  exudation  at  the  macula  lutea, 
without  any  similar  disease  elsewhere  in  the  fundus.  Absolute  central 
scotoma  is  its  prominent  symptom,  and  syphilis  its  usual  cause. 

Treatment. — Active  mercurialisation  ;  and,  where  this  can  be  adopted 
early,  the  prognosis  for  recovery  of  sight  is  fairly  good.  Sub-conjunctival 
salt  injections  aid  the  cure. 


192  DISEASES   OF   THE  EYE.  [chap.  vii. 

Senile  Central  Chorioiditis  occurs  as  a  well-defined  circular  or 
oval  area  of  superficial  atrophy  of  the  chorioid  at  the  macula,  which 
reveals  the  deeper  vessels.  It  is  met  with  in  old  people.  It  causes  a 
central  scotoma.  And  although  it  is  incurable,  the  patients  are  always 
able  to  get  about  by  themselves,  owing  to  the  retention  of  the  peripheral 
field  of  vision. 


Syphilitic  Chorioido-Eetinitis.— See  Syphilitic  Retinitis, 
chap.  xii. 

Purulent  Chorioiditis.— This  consists  at  first  in  a  purulent 
extravasation  between  the  chorioid  and  retina,  and  into  the 
vitreous  humour,  recognisable  by  the  yellowish  reflection  obtained 
from  the  interior  of  the  eye  on  illuminating  the  pupil  with 
the  ophthalmoscope  mirror.  The  eyeball  may  become  hard,  the 
pupil  dilated,  and  the  anterior  chamber  shallow.  Purulent  iritis 
with  hypopyon  soon  comes  on,  and  the  cornea  may  also  become 
infiltrated  and  slough  away.  There  is  usually  considerable  chemosis, 
and  the  eyeball  is  pushed  forwards  by  inflammatory  oedema  of  the 
orbital  connective  tissue.  The  eyelids  are  swollen  and  congested. 
There  is  intense  pulsating  pain  in  the  eye,  and  pains  radiate 
through  the  head  ;  and  in  this  stage  all  the  tissues  of  the  eyeball 
are  engaged  in  the  purulent  inflammation,  and  the  condition  is 
termed  Panophthalmitis.  It  is  the  streptococcal  infections  ^vhich 
end  in  this  way,  whereas  those  caused  by  the  pneumococcus  or 
meningococcus  usually  fall  short  of  panophthalmitis. 

The  pain  in  these  cases  is  not  severe  ;  and  when  the  affection 
occurs  in  children  it  may  be  mistaken  for  glioma  of  the  retina 
(chap,  xii.) ;  indeed,  the  name  '  pseudo-glioma '  has,  unfortunately, 
been  given  to  it.  It  must,  however,  be  stated,  that  very  recent 
investigations  go  to  show  that  pseudo-glioma  has  its  origin  in  the 
retina  rather  than  in  the  chorioid.  It  is  distinguished  from  glioma 
by  the  muddy  vitreous  usually  present  wath  it,  by  the  posterior 
synechise,  and  by  the  retraction  of  the  periphery  of  the  iris,  with 
bulging  forwards  of  its  pupillary  part. 

Causes. — This  form  of  chorioiditis  arises  as  an  embolic  or  meta- 
static chorioiditis,  in  connection  both  with  epidemic  and  sporadic 
cerebro-spinal  meningitis  (chap,  xiv.) ;  in  some  cases  of  metria, 
similarly  as  purulent  retinitis  (chap,  xii.) ;  in  pyaemia  of  the  ordinary 
type  ;   and  in  endocarditis. 

In  infancy  and  childhood,  besides  its  occurrence  with  cerebro- 


CHAP.  VII.]  THE    UVEAL    TRACT.  195 


spinal  meningitis,  it  has  been  known  to  be  caused  by,  or  associated 
with,  inherited  syphilis,  measles,  bronchitis,  diarrhoea,  whooping- 
cough,  and  omphalo-phlebitis  ;  and  some  infective  blood-disease 
is  the  fundamental  cause  of  the  process  in  every  case,  although  it 
is  not  always  possible  to  determine  its  source. 

Purulent  chorioiditis  may  also  be  caused  by  direct  infection, 
as  in  perforating  wounds  of  the  eyeball,  whether  accidental  or 
operative  ;  foreign  bodies  piercing  and  lodging  in  the  eyeball ;  and 
purulent  keratitis.  It  may  also  come  on  suddenly  in  eyes  which 
are  the  subjects  of  incarceration  of  the  iris  in  a  corneal  cicatrix, 
through  infection  of  the  incarcerated  iris.  The  bacillus  subtilis  and 
pyocyaneus  have  been  known  to  cause  it. 

Prognosis. — The  ultimate  result  in  the  vast  majority  of  cases 
is  loss  of  sight,  with  phthisis  bulbi.  The  severe  cases  go  on  to 
rupture  of  the  eyeball  through  the  cornea  or  sclerotic,  after  which 
the  pain  subsides.  It  would  seem  from  the  description  of  authors 
who  have  seen  much  of  epidemic  cerebro-spinal  meningitis,  that  a 
certain  number  of  cases  of  irido-chorioiditis  occurring  in  the  course 
of  that  disease  do  recover  with  retention  of  good  sight. 

The  shrunken  eyeballs  produced  by  panophthalmitis  are  not 
generally  painful  on  pressure.  They  are  not  very  liable  to  give 
rise  to  sympathetic  ophthalmitis,  and  the  latter  statement  is  also 
true  of  the  acute  purulent  process  itself.  It  is  cases  of  traumatic 
plastic  irido-chorioiditis  which  produce  sympathetic  ophthalmitis. 

Treatment  may  be  said  to  be  powerless  in  this  disease.  The 
utmost  one  can  do  is  to  endeavour  to  diminish  the  pain  in  the  very 
severe  cases  by  warm  fomentations,  poultices  containing  conium, 
hypodermic  injections  of  morphia,  or,  finally,  by  eviscerating  the 
suppurating  contents  of  the  scleral  cavity. 

Excision  of  the  eyeball,  according  to  some  surgeons,  should  not  be 
undertaken  during  purulent  chorioiditis  in  the  acute  stage,  through 
fear  that  it  might  cause  purulent  meningitis,  while  others  hold  that 
when  meningitis  follows  enucleation,  it  is  the  result  of  a  previous 
metastasis  and  is  not  attributable  to  the  operation,  and  therefore 
they  do  not  hesitate  to  enucleate  if  they  consider  it  necessary. 

Sympathetic  Ophthalmitis,  and  Sympathetic  Irritation. 

Introductory. — By    the    term     Sympathetic    Ophthalmitis    we 
understand  a  general  plastic  uveitis  (inflammation  of  iris,  ciliary 
13 


104  DISEASES   OF    THE   EYE.  [chap.  vit. 

body,  and  chorioid)  of  one  eye,  caused  by  a  plastic  uveitis  of  the 
other  eye,  the  latter  condition  being  most  commonly  due  to  a  per- 
forating trauma,  or  other  perforation  of  the  eyeball.  Occasionally 
sympathetic  ophthalmitis  takes  the  form  of  optic  neuritis  or 
chorioiditis. 

Purulent  uveitis  (panophthalmitis)  of  one  eye  does  not  cause 
uveitis,  either  plastic  or  purulent,  of  the  other  eye. 

There  are  no  such  diseases  as  sympathetic  cataract,  conjunc- 
tivitis, detachment  of  the  retina,  keratitis,  scleritis,  etc. 

The  term  '  sympathetic '  in  this  connection  is  an  old  one,  and 
probably  would  not  be  employed  had  the  disease  to  be  named  at 
the  present  time. 

Sympathetic  uveitis  cannot  be  developed  in  the  second  eye,  until 
after  uveitis  has  appeared  in  the  first  eye.  A  perforating  injury  of 
the  eyeball,  or  other  perforation,  which  does  not  produce  uveitis 
in  that  eye,  does  not  give  rise  to  sympathetic  ophthalmitis  in  the 
fellow  eye.  Yet,  traumatic  uveitis  in  the  injured  eye  does  not  cause 
sympathetic  ophthalmitis  in  every  case. 

The  eye  which  has  received  the  perforating  injury  is  spoken  of  as 
the  exciting  eye,  and  its  fellow,  which  becomes  the  subject  of  .  ym- 
pathetic  ophthalmitis,  as  the  sympathising  eye.  The  eyes  are  also 
spoken  of  as  the  injured  eye,  and  the  sympathising  eye  ;  also- as  the 
first  eye,  and  the  second  eye.^ 

While  sympathetic  ophthalmitis  is  not  a  reflex  condition,  there 
is  an  affection  known  as  sympathetic  irritation,  which  is  a  true 
fifth-nerve  reflex  neurosis.  These  two  affections,  although  some- 
times closely  associated  clinically,  are  quite  distinct  from  each 
other. 

Sympathetic  Irritatiox. — This  may  be  caused  by  almost  any- 
thing which  produces  irritability  of  the  ciliary  nerves  in  the  first 
eye — e.g.  foreign  bodies  on  the  cornea  or  under  the  upper  lid,  losses 
of  substance  of  the  corneal  epithelium,  anterior  staphyloma,  acute 
glaucoma,  iritis,  dislocation  of  the  crystalline  lens,  etc. 

The  most  common  symptoms  of  sympathetic  irritation  of  the 
second  eye  are  :  photophobia,  lacrimation,  vascular  injection  of  the 
front  of  the  eyeball,  and  accommodative  asthenopia,  and,  in  a  well- 

1  French  and  German  authors  term  the  injured  eye  the  sympathising 
eye,  and  the  second  eye  the  sympathised  eye. 


CHAP.  VII.]  TBE    UVEAL    TRACT.  195 

marked  case,  these  symptoms  become  intensely  distressing  to  the 
patient.  Neuralgia  in  the  orbit  and  brow,  and  retinal  asthenopia 
sometimes  occur. 

Amongst  the  many  causes  of  sympathetic  irritation  is  an  irritable 
shrunken  globe,  whether  the  latter  condition  be  the  result  of  a 
uveitis  from  a  perforating  injury,  or  of  an  idiopathic  uveitis  ;  and 
an  irritable  shrunken  globe  may  give  rise  to  sympathetic  irritation 
in  the  fellow  eye  at  any  time,  even  after  many  years.  Having 
remained  quiet  for  so  long,  the  shrunken  eye  begins  to  lacrimate, 
and  becomes  painful  and  injected.  A  fresh  injury  to  the  stump  may 
be  the  cause  of  this,  or  it  may  be  ossification  of  its  chorioid,  and 
the  irritation,  whatever  its  cause,  may  be  transmitted  to  the 
sound  eye. 

But  sympathetic  ophthalmitis  also  is  often  caused  by  a  shrunken 
fellow  eyeball,  in  which  uveitis  is  present  {vide  infra)  ;  and  of  great 
importance  is  the  qxiestion  :  What  relation,  if  any,  has  sympathetic 
irritation  to  sympathetic  ophthalmitis  in  such  cases  ?  Is  sym- 
pathetic irritation  to  be  regarded  as  a  reliable  and  essential  pre- 
monitory symptom  of  sympathetic  ophthalmitis  ?  The  answer  is 
in  the  negative.  Sympathetic  irritation  may  last  an  indefinitely 
long  time,  without  being  followed  by  sympathetic  ophthalmitis. 
Further,  although  some  sign  or  signs  of  sympathetic  irritation  often 
do  precede  the  onset  of  sympathetic  ophthalmitis,  yet  in  many  cases 
every  such  sign  is  wanting.  In  view  of  the  latter  fact,  it  is,  therefore, 
wrong  to  postpone  a  prophylactic  enucleation,  until  sympathetic 
irritation  shows  itself. 

Treatment. — When  sympathetic  irritation  is  caused  by  an  irritable 
shrunken  globe  on  the  opposite  side,  it  can  be  immediately  relieved 
by  removal  of  the  stump.  Rest  in  a  dark  room  and  sedative  measures, 
while  they  may  seem  to  cure,  merely  lead  to  disappointment,  owing 
to  the  almost  certain  return  of  the  symptoms,  when  the  eye  is 
brought  into  use  again.  Moreover,  as  sympathetic  irritation  does 
often  precede  sympathetic  inflammation,  it  is  wise  to  enucleate  the 
exciting  stump  in  order  to  assure  the  safety  of  the  second  eye. 

Sympathetic  Ophthalmitis.  Diagnosis. — The  inflammation  of 
the  uveal  tract  in  the  sympathising  eye  has  no  characteristics  which 
enable  us  to  make  the  diagnosis  '  Sympathetic  Ophthalmitis,'  for 
precisely  the  same  plastic  or  sero-plastic  uveitis,  as  the  case  may  be, 


10(i  DISEASES    OF    THE   EYE.  [chap.  vii. 

is  seen  under  utlier  conditions  ;  nor  is  the  state  of  the  first  eye,  taken 
alone,  a  certain  guide.  To  arrive  at  a  diagnosis,  it  is  necessary  to 
weigh  the  following  data,  and  to  take  them  c-ollcctively  into  con- 
sideration : — 

1.  The  condition  of  the  exciting  eye.  and  the  nature  of  the 
injury  to.  or  disease  of.  that  eye.    . 

2.  The  condition  of  the  sympathising  eye. 

3.  The  interval  that  has  elapsed  between  the  injury  to  the 
exciting  eye,  and  the  onset  of  the  uveitis  in  the  sympathising  eye. 

4.  The  state  of  the  general  system. 

1.  The  Condition  of  the  Exciting  Eye. — As  already  stated,  per- 
forating injuries,  or  perforating  corneal  ulcers,  of  the  first  or  exciting 
eve,  which  are  followed  by  plastic  uveitis,  are  by  far  the  most  com- 
mon causes  of  sympathetic  ophthalmitis.  The  position  of  the  wound 
in  the  eye  has  no  influence  in  the  production  of  sympathetic  oph- 
thalmitis. Uveitis  in  the  injured  eye  is  due  to  infection  of  the 
wound  by  micro-organisms  derived  from  the  foreign  body,  or  instru- 
ment, which  has  caused  the  wound,  but  sometimes  perhaps  from 
the  surface  of  the  eye. 

Either  a  purulent  uveitis,  or  a  plastic  uveitis,  may  result  from 
the  injury. 

Purulent  uveitis  of  a  not  very  pronounced  type  (purulent  in- 
filtration of  the  vitreous  humour,  iritis,  hypopyon)  is  very  occasionally 
followed  by  sympathetic  ophthalmitis,  but,  and  it  is  a  remarkable 
clinical  fact,  the  marked  purulent  uveitis,  which  is  called  panoph- 
thalmitis (p.  192),  may  be  said  never  to  give  rise  to  it.  It  is  obvi- 
ouslv  not  a  pyogenic  micro-organism  which  causes  sympathetic 
ophthalmitis — for,  if  it  were,  the  latter  would  be  a  purulent  process — 
but  it  may  be  some  specific  micro-organism. 

If  the  infection  of  the  injured  eye  be  purulent,  the  inflammatory 
reaction  in  it  comes  on  within  the  first  thirty-six  hours  after  the 
injury  ;  while  the  fibrinous  or  plastic  inflammatory  reaction,  which 
is  so  dangerous  in  relation  to  sympathetic  ophthalmitis,  and  which 
is  caused  by  the  specific  organism,  declares  itself  in  the  injured  eye 
less  quickly  and  more  insidiously. 

In  the  case  of  the  latter  infection,  the  injection  and  irritation — 
immediate  results  of  the  injury — disappear  in  a  few  days,  but  soon 
return.  The  pupil  then  begins  to  dilate  less  well  to  atropine,  the 
tissue  of  the  iris  becomes  less  distinctly  seen,  some  punctate  deposits 


CHAP.  VII.]  THE    UVEAL    TRACT.  197 

appear  on  the  posterior  surface  of  the  cornea,  a  few  posterior 
synechiix^  form,  and  opacities  appear  in  the  vitreous  humour.  At 
first  there  is  little  or  no  pain,  either  spontaneously  or  on  pressure, 
and  in  this  stage  treatment  may  produce  a  marked  improvement. 
But  sooner  or  later  a  relapse  occurs,  more  synechise  form,  the  iris 
stroma  becomes  more  indistinct  and  discoloured,  often  of  a  dull 
greenish  or  yellowish  grey,  and  the  pupil  becomes  occluded.  The 
anterior  chamber  becomes  shallower  than  normal,  and  the  intra- 
ocular pressure  is  diminished.  Sight  is  much  impeded  by  exudation 
in  the  pupil  and  by  opacities  in  the  vitreous,  and,  in  case  of  detach- 
ment of  the  retina  from  shrinking  of  the  inflammatory  products 
in  the  vitreous  humour,  it  may  be  reduced  in  a  marked  degree. 
There  now  is  often  pain  on  pressure  of  the  eyeball,  and  the  latter 
soon  begins  to  be  diminished  in  size  and  becomes  soft  to  the  touch, 
while  the  pressure  of  the  tendons  of  the  orbital  muscles  on  this  soft 
eyeball  gives  rise  to  deep  furrows  on  its  surface.  In  short,  the 
injured  eye  has  now  become  phthisical,  and  sight  is  quite  lost.  This 
entire  process  may  be  completed  in  three  or  four  weeks,  or  it  may 
occupy  a  considerably  longer  time. 

The  danger  of  sympathetic  ophthalmitis  supervening  on  a  per- 
forating injury  of  the  first  eye  commences  with  the  onset  of  plastic 
uveitis  in  the  injured  eye — although  the  inflammatory  process  in 
the  second  eye  does  not  develop  until  after  a  certain  interval  {vide 
infra) — and  this  danger  is  present,  not  only  all  through  the  acute 
process  in  the  injured  eye,  but  also  after  this  has  subsided,  and 
when  the  eye  has  become  shrunken,  and  even  for  many  years  more. 

Shrunken  eyeballs,  as  just  stated,  are  liable  to  cause  sympathetic 
ophthalmitis.  Pain  on  pressure  of  the  ciliary  region  in  them,  show- 
ing, as  it  does,  the  presence  of  inflammation  of  the  ciliary  body, 
is  an  important  danger-signal  ;  but  the  absence  of  pain  on  pressure 
is  not  conclusive  of  the  absence  of  cyclitis,  for  the  latter  may  exist 
to  only  a  slight  and  yet  dangerous  degree,  or  the  ciliary  body  may 
be  detached  and  out  of  reach  of  pressure. 

The  presence  of  a  foreign  body  in  the  interior  of  the  injured  eye 
does  not  necessarily  lead  to  sympathetic  ophthalmitis  by  the  in- 
flammatory reaction  which  it  may  cause  ;  for  an  aseptic  foreign  body 
in  the  eye  will  cause  an  active  inflammatory  reaction  ;  yet  this  latter, 
not  being  of  bacterial  origin,  will  not  in  its  turn  give  rise  to  sym- 
pathetic  ophthalmitis.     There   are,    however,    few   foreign    bodies, 


198  DISEASES    OF    THE   EYE.  [chap.  vii. 


except  atoms  of  hot  metal,  which  can  be  guaranteed  as  free  from 
infective  material ;  hence,  as  a  rule,  the  presence  of  a  foreign  body 
within  the  eye  augments  the  danger  of  a  perforating  injury. 

As  in  accidental  perforating  injuries,  so  also  the  wounds  made  in 
the  sclerotic  or  cornea  in  surgical  operations,  especially  in  cataract 
extractions,  may  be  followed  by  plastic  uveitis,  which  will  produce 
sympathetic  ophthalmitis.  In  consequence  of  the  thorough  aseptic 
measures  now  in  use,  inflammatory  processes  after  cataract  extrac- 
tions are  very  much  less  common  than  they  used  to  be. 

Perforations  caused  by  ulcers  of  the  cornea  sometimes  give  rise 
to  uveitis,  which  may  be  followed  by  sympathetic  ophthalmitis  ;  but 
this  is  a  rare  event,  although  some  iritis  is  present  with  almost  every 
severe  corneal  ulcer,  and  especially  with  those  which  tend  to  per- 
forate. It  is  not  easy  to  assign  a  reason  for  the  rare  occurrence  of 
sympathetic  ophthalmitis  in  these  cases. 

In  how  far  plastic  uveitis  of  the  first  eye,  which  is  not  due 
to  perforating  injuries  or  ulcers,  is  capable  of  being  the  cause  of 
sympathetic  ophthalmitis  is  an  important  question. 

Intra-ocular  tumours,  which  have  not  yet  perforated  the  sclerotic, 
especially  sarcoma  of  the  chorioid,  very  occasionally  set  up  a  uveitis, 
which  leads  to  sympathetic  ophthalmitis.  In  these  cases  necrosis 
of  the  tumour  has  generally  set  in. 

Ruptures  of  the  eyeball  from  blows,  which  usually  occur  in  the 
ciliary  region,  without  rupture  of  the  conjunctiva — sub-conjunctival 
ruptures  of  the  sclerotic — sometimes  come  under  our  notice  (p.  169). 
These  injuries  almost  invariably  run  a  course  free  from  inflammation 
or  even  irritation  of  the  injured  eye,  owing  to  the  unbroken  con- 
junctiva, which  covers  the  rupture,  and  prevents  the  access  of 
infecting  bacteria  ;  and,  consequently,  they  may  be  said  not  to 
cause  sympathetic  ophthalmitis.  It  is  probable  that  in  the  few 
cases  of  this  injury  in  which  uveitis  in  the  injured  eye  and  sympathetic 
ophthalmitis  in  the  second  eye  appeared,  some  small  opening  in  the 
apparently  sound  conjunctiva  existed. 

Cases  of  gonorrhoeal  ophthalmia  have  been  published  in  which 
sympathetic  ophthalmitis  came  on.  But  these  were  all  cases  in 
which  ulceration,  followed  by  perforation  of  the  cornea,  took  place  ; 
and,  hence,  in  which  infection  by  bacteria  other  than  the  gonococcus 
was  quite  possible. 

2.  The  Condition  oj  the  Sympathising  Eye. — The  diseased  process 


CHAP.  VII.]  THE    UVEAL    TRACT.  199 


in  the  second  or  sympathising  eye,  as  has  already  been  stated,  is, 
with  certain  rare  exceptions,  an  inflammation  of  the  uvea,  of  a  plastic 
or  fibrinous  type,  but  never  purulent,  and  almost  always  begins  in 
the  uvea,  or,  at  any  rate,  is  commonly  first  discovered  there  as 
iritis. 

In  the  rare  exceptions  referred  to,  optic  neuritis  is  the  first  sign 
of  sympathetic  ophthalmitis,  uveitis  coming  on  subsequently  ;  and, 
yet  more  rarely,  optic  neuritis  has  been  seen  as  the  one  and  only 
sympathetic  inflammation,  the  uvea  remaining  unaffected.  It  is, 
however,  held  by  some,  that  optic  neuritis  would  be  found  to  be  the 
first  sign  in  the  sympathising  eye  in  nearly  all  cases  if  it  were  possible 
to  examine  them  before  opacities  in  the  vitreous  humour,  and 
exudation  in  the  pupil,  interfere  with  an  ophthalmoscopic  diagnosis. 

The  appearance  of  the  optic  neuritis,  or  papillitis,  as  seen  in 
these  cases,  consists  in  hypersemia  of  the  disc,  without  much  swelling 
of  the  latter,  but  with  slight  woolliness  of  its  margin,  the  opacity 
spreading  a  short  distance  into  the  surrounding  retina.  The  veins 
are  distended,  and  the  arteries  are  normal.  The  sight  is  considerably 
affected,  and  there  is  often  rather  severe  headache.  The  remedy 
for  sympathetic  papillitis,  occurring  alone,  is  removal  of  the  exciting 
eye,  and  a  few  days  after  the  operation  the  beneficial  effect  on  the 
optic  nerve  inflammation  begins  to  show  itself. 

There  are  no  reliable  premonitory  symptoms  of  the  attack  of 
uveitis  in  the  sympathising  eye.  As  already  stated,  in  many  cases 
sympathetic  irritation  does  precede  the  first  signs  of  sympathetic 
uveitis,  but  it  does  not  always  do  so  ;  and  when  sympathetic 
irritation  does  appear,  it  need  not  always  indicate  the  approach  of 
sympathetic  uveitis. 

The  early  signs  of  the  actual  presence  of  uveitis  in  the  sym- 
pathising eye  are  : — some  fine  punctate  deposits  on  the  posterior 
surface  of  the  cornea,  and  these  are  often  the  first  symptom  ;  slight 
pericorneal  injection  ;  slight  opacity  of  the  aqueous  humour  ;  some 
discoloration  and  indistinctness  of  the  iris  ;  contraction  of  the  pupil, 
but  as  yet  no  synechise  ;  some  fine  opacities  in  the  vitreous  humour ; 
and  slight  loss  of  sight  owing  to  these  changes. 

Posterior  synechiae  soon  begin  to  form,  and,  in  the  most  serious 
cases,  the  adhesions  occur,  not  merely  between  the  margin  of  the 
pupil  and  the  anterior  capsule  of  the  lens,  but,  after  a  little  while, 
between  the  whole  of  the  posterior  surface  of  the  iris  and  the  capsule 


200  DISEASES   OF    THE   EYE.  [chap.  vii. 

— total  posterior  synechia.  The  exudation  which  causes  this  exten- 
sive adhesion  soon  pushes  the  iris  forward — iris  bombe— and  renders 
the  anterior  chamber  shallow  ;  but  after  a  time,  when  the  fibrinous 
exudation  begins  to  shrink,  the  anterior  chamber  becomes  deep  at 
its  periphery,  owing  to  retraction  of  the  iris.  The  iris  gradually 
becomes  more  altered,  its  tissue  more  dull,  discoloured,  and  in- 
distinct, while  large  vessels  form  in  it.  Occasionally,  in  the  anterior 
chamber  a  small  pseudo-hypopyon  is  seen,  formed  by  the  fibrin 
which  floats  in  the  aqueous  humour,  some  of  which  has  gravitated. 

The  intra-ocular  tension  may  become  high,  often  very  high, 
owing  to  blocking  of  the  angle  of  the  anterior  chamber  with  in- 
flammatory products,  and  this  glaucomatous  tension  is  apt  to  be 
attended  by  great  pain.  In  consequence  of  the  presence  of  such 
extensive  adhesions,  eserine  and  pilocarpine  have  no  influence  on 
this  high  tension,  and  the  temptation  to  perform  an  iridectomy  is 
very  great. 

Yet  it  may  be  stated  at  once  that  no  graver  mistake  can  be 
made  in  ophthalmic  practice  than  to  venture  on  any  operative  inter- 
ference at  this  period.  Far  from  doing  good,  an  iridectomy  is  almost 
certain  to  do  harm.  It  is  impossible,  owing  to  the  disorganised  state 
of  the  iris  and  its  close  adherence  to  the  anterior  capsule,  to  obtain 
anything  like  a  satisfactory  coloboma  ;  and  even  if  the  tension  be 
reduced  for  a  day  or  two  after  the  operation,  it  soon  becon>es  as 
high  as  before,  in  consequence  of  the  rapid  filling  up  of  the  coloboma 
by  proliferation  of  the  inflammatory  products,  while  the  traumatism 
of  the  operation  only  seems  to  lend  additional  violence  to  the 
inflammation. 

In  the  further  progress  of  the  disease,  the  cornea  gradually 
becomes  more  or  less  opaque,  from  derangement  of  its  posterior 
epithelium  by  the  punctate  deposits  of  fibrin  upon  it,  and  the  crystal- 
line lens  becomes  cataractous.  After  a  time  the  high  tension  dis- 
appears, and  gradually,  owing  to  shrinking  of  the  vitreous  humour. 
low  tension  comes  on.  Vision,  already  very  bad,  sinks  further.  The 
eyeball  becomes  smaller  and  very  soft  to  the  touch,  and  phthisis 
bulbi,  with  complete  blindness,  is  j^resented.  This  entire  process 
may  occupy  many  months,  and  is  often  interrupted  by  short  periods 
of  slight  improvement  in  the  symptoms,  which  raise  the  hope  of 
patient  and  surgeon. 

In  rai'e  cases,   the  sympathetic  uveitis  comes  on  with   violent 


CHAP.  VII.]  THE    UVEAL    TRACT.      _  201 


pain,  chemosis,  and  swelling  of  the  eyelids,  and  ends  rapidly  in 
phthisis  bulbi. 

On  the  other  hand,  there  is  a  less  severe  class  of  cases,  in  which 
total  posterior  synechia  does  not  form,  the  pupillary  margin  alone 
becoming  adherent,  and  these  cases  may  run  a  comparatively  favour- 
able course. 

A  yet  milder,  and  not  uncommon,  form  of  sympathetic  uveitis 
is  that  in  which  the  only  signs  are  : — punctate  deposits  on  the 
posterior  surface  of  the  cornea,  and  increased  depth  of  the  anterior 
chamber,  without  any  iritis.  The  punctate  deposits  are  often  at 
first  so  fine  as  to  be  undiscoverable,  unless  by  aid  of  a  high  convex 
lens  behind  the  sight -hole  of  the  ophthalmoscope,  or  with  a  corneal 
microscope.  This  form  of  sympathetic  ophthalmitis  is  termed 
serous  sympathetic  uveitis,  and  its  prognosis  is  favourable.  Its 
one  danger  consists  in  the  increased  intra-ocular  tension  which  is 
liable  to  come  on,  but  which  should  not  tempt  the  surgeon  to  employ 
an  iridectomy,  whereby  a  mild  process  might  be  converted  into  a 
severe  one. 

More  common  than  this  typical  serous  uveitis  are  cases  in  which 
some  fibrin  is  thrown  out,  with  resulting  posterior  synechia3  at  the 
pupillary  margin,  and  where  small  round  yellowish-white  deposits 
may  be  found  with  the  ophthalmoscope  in  the  chorioid — called 
sympathetic  disseminated  chorioiditis — especially  towards  the  peri- 
phery of  the  fundus.  In  some  cases  the  iris  is  free  from  inflam- 
mation, the  chorioid  alone  being  affected  in  the  manner  mentioned. 
This  form  of  sympathetic  ophthalmitis  is  not  attended  by  much 
irritation  of  the  eye,  nor  need  vision  be  much  affected.  The  corneal 
deposits  very  gradually  increase  in  number,  and  consequently,  vision 
becomes  affected  to  some  extent,  and  then,  if  the  tension  do  not 
increase,  the  signs  and  symptoms  after  a  time  very  slowly  abate, 
and  a  normal  state  is  re-established.  But  relapses  are  liable  to 
occur  even  after  some  months,  and  they  may  assume  the  very 
dangerous  fibrinous  type,  vSo  that,  even  in  these  mildest  cases, 
the  utmost  care  in  treatment  and  prognosis  is  needed. 

3.  The  Interval  that  has  elapsed  between  the  Injury  to  the  Exciting 
Eye,  and  the  Onset  of  Uveitis  in  the  Sympathising  Eye. — So  far  as 
our  present  knowledge  based  on  reliable  cases  enables  an  opinion 
to  be  formed,  the  shortest  interval  which  occurs  between  the  injury 
to  the  first  eve,  and  the  onset  of  uveitis  in  the  second  eve,  is  fourteen 


202  DISEASES    OF    THE   EYE.  [chap.  vii. 

days,  and  very  few  cases  with  this  shortest  interval  have  been 
reported.  The  period  between  the  sixth  and  twelfth  week  after  the 
injury  seems  to  be  the  most  dangerous.  In  170  of  the  200  cases 
collected  by  the  Committee  on  Sympathetic  Ophthalmitis  of  the 
Ophthalmological  Society  the  second  eye  was  attacked  within  the 
first  year  after  the  injury  to  the  exciting  eye.  In  only  12  of 
the  200  cases  was  the  interval  more  than  one  year,  and  the 
longest  interval  was  twenty  years. 

•i.  The  State  of  the  General  System. — As  the  subjects  of  traumatic 
plastic  uveitis  in  one  eye  are  not  immune  against  plastic  uveitis  in 
the  other  eye  due  to  syphilis,  rheumatism,  tubercle,  diabetes,  etc., 
it  is  necessary  in  each  case  to  consider,  whether  the  attack  in  the 
second  eye  may  not  be  a  symptom  of  some  systemic  condition, 
rather  than  a  sympathetic  uveitis. 

From  the  above  it  appears,  then,  that  the  diagnosis  of  sym- 
pathetic ophthalmitis  depends  on  the  following  evidence  : — (1)  As 
regards  the  exciting  eye  :  Uveitis  after  perforation  of  the  eyeball ; 
except  that  in  the  rare  cases  in  which  sympathetic  ophthalmitis  is 
caused  by  a  chorioidal  sarcoma,  perforation  is  not  necessary.  (2)  As 
regards  the  sympathising  eye  :  an  inflammatory  process  of  a  plastic 
type,  which  attacks  all  three  portions  of  the  uveal  tract,  is  very 
chronic  in  its  course,  often  improves  for  a  while,  but  relapses  again. 
(3)  As  regards  the  interval  between  the  perforating  injury  in  the 
first  eye,  and  the  appearance  of  sympathetic  ophthalmitis  :  an 
interval  of  at  least  fourteen  days  is  required.  The  period  between 
the  sixth  and  twelfth  week  is  the  most  dangerous,  and  very  few 
cases  occur  after  the  first  year.  (4)  As  regards  the  general  system  : 
when  careful  examination  of  it  does  not  reveal  any  condition,  which 
might  be  the  cause  of  uveitis  in  the  second  eye,  the  probability  of 
this  uveitis  being  sympathetic  is  increased. 

Cases  of  Sympathetic  Ophthalmitis  have  been  recorded  associated 
with  headache,  with  blanching  of  the  cilia  or  eyebrows,  and  with  deafness. 
The  loss  of  hearing  was  bilateral  and  was  in  most  cases  incurable. 

Prognosis. — The  prognosis  of  sympathetic  uveitis  is,  in  general, 
serious  ;  yet  it  need  not  be  quite  hopeless,  for  even  in  severe  cases 
very  occasionally,  and  of  course  more  frequently  in  the  less  severe 
cases,  the  sympathising  eye  does  recover  after  prolonged  treatment, 
with  a  useful  amount  of  vision.     But  in  these  rare  cases  which  under- 


CHAP.  VII.]  THE    UVEAL    TRACT.  203 

go  cure,  the  eyes  are  liable  to  occasional  recurrences  of  the  uveitis, 
and  at  least  a  year  should  elapse  since  the  last  recurrence,  before 
a  definite  end  to  the  diseased  process  can  be  said  to  have  been  reached. 

The  prognosis  of  sympathetic  papillitis  is  quite  favourable,  when 
once  the  exciting  eye  has  been  removed. 

Treatment. — Measures  calculated  to  prevent  the  onset  of  sym- 
pathetic ophthalmitis  are  of  the  first  importance.  Where  the 
injury  is  so  extensive  as  to  make  all  prospect  of  saving  sight  in  the 
first  eye  hopeless,  immediate  excision  of  that  globe  is  obviously 
indicated.  Where  some  prospect  of  saving  sight  in  the  injured  eye 
exists,  attention  is  claimed  in  the  first  instance  by  the  wound,  which, 
in  those  cases  that  come  for  surgical  aid  sufficiently  early,  is  to  be 
protected  from  secondary  infection  by  careful  antiseptic  cleansing, 
abscission  of  any  prolapsed  portions  of  the  uvea,  suturing  of  the 
wound  in  suitable  cases,  and  dressing  w4th  bandage. 

Should  the  wound  be  already  infected,  excision  of  the  injured 
eyeball  is  called  for.  No  temporising  is  admissible — even  some 
useful  vision  being,  for  the  time,  retained  by  the  injured  eye  is  not  a 
contra-indication  to  the  operation. 

Where  sight  in  the  injured  eye  is  lost,  it  will  not  be  difficult  for 
the  surgeon  to  recommend  excision  of  the  eyeball,  and  even  to  urge 
it  on  the  patient ;  but  when  some  useful  sight  is  still  retained,  it  s 
not  so  easy  to  press  this  advice,  although  that  should  be  done.  We 
know,  indeed,  that  in  some  cases  of  traumatic  uveitis  sympathetic 
uveitis  does  not  supervene  ;  and,  provided  the  first  eye  be  not  too 
much  disorganised  by  the  injury,  sight  in  it  may  ultimately  be 
obtained.  But,  unfortunately,  we  are  unable  to  foretell  whether 
any  given  case  will  run  so  favourable  a  course  ;  and  to  temporise, 
in  the  hope  that  it  will  do  so,  involves  serious  danger  to  the  second 
eye,  and,  it  may  be,  ultimate  loss  of  all  sight  in  each  eye. 

In  short,  it  cannot  be  doubted  that  there  are  cases  in  wdiich, 
in  the  present  state  of  our  knowledge,  we  recommend  removal  of  the 
injured  eye  and  where,  had  we  decided  to  run  a  fearful  risk  by 
allowing  it  to  remain,  not  only  would  sight  have  been  restored  to  it, 
but  no  sympathetic  ophthalmitis  would  have  come  on. 

It  must  be  further  stated,  that  we  cannot  feel  sure  that  our 
removal  of  the  first  eye  has  averted  sympathetic  ophthalmitis  from 
the  second  eye,  until  four  weeks  after  the  operation  has  elapsed. 

Nearly  every  ophthalmic  surgeon  has  seen  cases  in  which  sym- 


204  DISEASES    OF    THE   EYE.  [chat.  vit. 


pathetic  ophthalmitis  has  appeared  subsequently  to  excision  of  the 
first  eye,  and  in  which,  at  the  time  of  the  operation,  the  second  eye 
was  perfectly  sound.  There  are  well-authenticated  cases  where 
sympathetic  ophthalmitis  appeared  as  long  as  four  weeks  after 
enucleation  of  the  injured  eye.  These  cases  are  deplorable  for  the 
patient,  and  very  trying  for  the  surgeon,  especially  if  the  outbreak 
of  sympathetic  ophthalmitis  should  occur  very  soon  after — perhaps 
the  day  after — the  operation.  Yet,  where  sympathetic  ophthalmitis 
comes  on  after  excision  of  the  first  eye,  the  operation  need  not  be 
regarded  as  having  been  quite  useless  ;  for  experience  shows  that  the 
attack  of  uveitis  in  the  second  eye  is  then  usually  of  a  comparatively 
mild  type,  and  fairly  amenable  to  treatment. 

In  those  cases  in  which  the  exciting  eye  has  not  yet  been  removed, 
and  in  which  sympathetic  ophthalmitis  in  the  second  eye  has  com- 
menced, what  are  our  duties  ?  In  the  first  instance,  and  at  the  earliest 
possible  moment,  the  exciting  eye  should  be  removed,  always  pro- 
vided that  it  be  quite  and  hopelessly  blind.  The  immediate  result  on 
the  second  eye  of  removal  of  the  first  eye  under  these  conditions  is 
not  marked,  for  the  inflammatory  process  in  the  former  seems  to 
proceed  as  actively  as  before.  But  statistics  show  that  more  svm- 
pathising  eyes  are  saved,  or  partially  saved,  when  the  injured  eye 
has  been  removed  soon  after  the  outbreak  of  sympathetic  ophthal- 
mitis, than  when  the  injured  eye  is  removed  a  considerable  time 
after  the  outbreak,  or  not  at  all. 

But  no  exciting  eye,  which  possesses  even  a  slight  degree  of  sight, 
should  be  removed  when  once  sympathetic  ophthalmitis  has  appeared. 
For  it  may  well  happen,  that  the  sympathising  eye  becomes  entirely 
lost,  while  the  exciting  eye  ultimately  retains  some  degree  of  useful 
sight.  Great  caution  is  therefore  required  in  deciding  whether  the 
exciting  eye  be  capable  of  recovering  to  a  certain  extent,  and  this 
frequently  is  a  matter  of  considerable  difficulty.  Even  a  partially 
phthisical  eyeball  may  sometimes  ultimately  come  round  sufficiently 
to  gain  useful  vision.  Schirmer  lays  down  the  following  rule  : — "When 
sympathetic  ophthalmitis  has  broken  out,  the  exciting  eye  should  not 
be  removed,  unless  it  be  absolutely  blind  ;  or  unless — if  it  still  possess 
merely  perception  of  light — it  has  been  for  several  weeks  very  soft, 
and  reduced  in  size  ;  or  that,  by  reason  of  extensive  corneal  opacity, 
all  hope  of  restoration  of  form-vision  must  be  abandoned. 

If  sympathetic  ophthahnitis  have  b]-oken  out.  either  before  or 


CHAP,  vji.l  THE    UVEAL   TRACT.  205 


after  removal  of  the  exciting  eye.  the  treatment  and  care  of  the 
sympathising  eye  to  promote  its  recovery  must  be  considered. 
This  consists  in  the  use  of  atropine,  warm  fomentations,  and 
sub-con junctival  saline  injections,  which  latter  are  held  by  some 
to  be  very  beneficial  when  high  tension  is  present  ;  paracentesis 
also  does  good  in  such  an  event.  With  these  local  means  is  com- 
bined a  general  and  prolonged  course  of  mercurialisation — mercurial 
inunctions  or  calomel  internally,  or  both,  care  being  taken  to  avoid 
any  severe  stomatitis.  We  can  speak  very  favourably  of  salicylate 
of  soda  in  gradually  increasing  doses  until  140  or  150  grains  are 
taken  daily.  Salvarsan  has  given  good  results  in  the  hands  ot 
some,  while  again  it  has  proved  disappointing.  The  patient  is 
to  be  confined  in  one  warm  but  well-ventilated  room,  which  should 
be  kept  almost  dark.  As  this  treatment  must  often  be  continued 
for  many  weeks  or  even  months,  it  is  trying  for  the  patient  ;  but  it 
is  to  be  remembered  that  the  issue  at  stake  is  a  fateful  one. 

No  operation  on  the  iris  is  to  be  performed  so  long  as  there  is 
the  slightest  inflammation,  or  tendency  to  inflammation  ;  and  this 
rule  holds  good,  even  if  the  tension  of  the  eye  become  glaucomatous. 
Premature  operative  interference  has  only  the  effect  of  lighting  up 
fresh  inflammation  ;  and,  even  if  the  tension  be  reduced  by  an 
iridectomy — which  latter,  owing  to  the  diseased  and  degenerated 
state  of  the  iris  and  the  inflammatory  exudation  behind  it,  cannot  be 
satisfactorily  carried  out — it  w^ill  soon  again  become  high.  In  six 
months  or  a  year  after  every  slight  sign  of  inflammation,  or  tendency 
to  inflammation — of  which  injection  of  the  ciliary  vessels  on  inser- 
tion of  a  spring  speculum  is  not  a  bad  criterion — has  passed  away, 
and  a  longer  interval  can  only  be  of  advantage,  it  may  be  allowable 
to  perform  an  operation  with  the  object  of  making  an  artificial  pupil, 
always  provided  that  there  is  good  prospect  of  materially  improving 
vision  by  this  means.  It  must  be  remembered  that,  while  every 
operation  has  its  risks,  the  risks  are  unusually  great  in  such  dis- 
organised eyes  ;  and  that  any  loss  of  sight  is  felt  all  the  more  in  a 
case  in  which  the  eye  operated  on  is  probably  the  only  one  possessing 
even  a  little  vision.  On  the  other  hand,  when  success  crowns  an 
operation  in  these  sad  and  perplexing  cases,  the  gain  is  great. 

If  it  be  decided  not  to  remove  the  exciting  eye,  after  sympathetic 
ophthalmitis  has  broken  out,  then  the  inflammatory  process  in  it 
is  treated  on  lines  quite  similar  to  those  above  recommended  for 


206  DISEASES   OF   THE   EYE.  [chap.  vn. 

the  sympatliisiiig   eye,    and  the   advice  as   regards    operations   is 
the  same. 

Prophylactic  Operations  used  for   Sympathetic  Ophthalmitis, 

performed  on  the  exciting  eye. 

Enucleation  {or  Excision). — Of  prophylactic  operations  for  sym- 
pathetic ophthalmitis,  enucleation  of  the  first  eye  is  the  only  one 
which  is  regarded  by  all  ophthalmic  surgeons  as  thoroughly  reliable, 
when  it  is  performed  in  time. 

The  speculum  having  been  inserted,  an  incision  is  made  in  the 
conjunctiva  all  round  the  cornea.  The  bulbar  conjunctiva  is  separ- 
ated from  the  globe  freely  in  all  directions  with  scissors.  With  a 
strabismus  hook  each  orbital  muscle  is  caught  up,  and  its  tendon 
divided  close  to  the  sclerotic.  The  eyeball  is  then  made  to  start 
forward  by  pressure  of  the  speculum  backwards,  or  the  eye  is  seized 
by  the  stump  of  the  external  rectus  tendon  and  drawn  forwards  and 
inwards.  The  optic  nerve  is  then  divided  with  strong  scissors  passed 
into  the  orbit,  either  from  the  median  or  from  the  temporal  side, 
as  far  back  in  the  orbit  as  possible.     Sutures  are  not  necessary. 

Careful  asepsis  is  of  course  necessary  in  enucleation  of  the  globe. 
Next  to  thorough  sterilisation  of  the  instruments,  irrigation  of  the 
cavity  of  the  orbit  as  soon  as  the  eyeball  is  removed,  with  a  full 
stream  of  sublimate  solution,  1  in  5000,  or  of  sterilised  normal  salt 
solution,  is  the  most  important.  Xeroform,  or  other  fine  antiseptic 
powder,  may  be  dusted  into  the  orbit,  and  an  aseptic  dressing 
should  be  applied  with  a  pressure  bandage.  The  orbit  should  be 
similarly  dressed  every  twenty-four  hours. 

Some  cases  of  meningitis  following  upon  the  operation,  and 
which  have  proved  fatal,  are  reported.  There  can  be  no  reasonable 
doubt  but  that,  in  some  of  these  cases,  septic  matter  made  its  way 
along  the  lymphatics  of  the  optic  nerve  to  the  meninges,  and  that  this 
septic  matter  was  introduced  upon  the  instruments,  or  escaped,  in 
purulent  cases,  from  the  interior  of  the  eyeball.  Hence  the  very 
great  importance  of  the  careful  aseptic  precautions  above  indicated. 

An  artificial  eye  can  usually  be  inserted  after  a  fortnight,  but 
should  not  be  constantly  worn  for  a  month  at  least,  because  it  is 
liable  to  cause  irritation  and  conjunctivitis  until  that  time  has 
elapsed. 

Artificial  Eyes  {Prothesis  Oculi). — These  should  be  worn  after  enuclea- 
tion, not  merely  for  the  cosmetic  effect,  but  also  because  they  prevent 


CHAP.  VII.]  THE    UVEAL    TRACT.  207 

the  occurrence  of  entropion  and  are  better  for  the  socket.  Thoy  are 
sometimes  used  over  a  phthisical  eyeball,  and  in  such  cases  they  look 
very  well  and  have  a  greater  range  of  movement  than  after  an  enucleation. 
Glass  eyes  are  made  in  two  forms,  the  simple  shell  and  the  "  reform  " 
eye,  which  is  hollow  inside.  The  latter  is  more  comfortable,  as  its  edges 
are  more  rounded,  besides  having  the  advantage  of  filling  the  orbital 
cavity  better.  A  slight  concavity  at  the  upper  margin,  which  comes  to 
lie  opposite  the  supra-orbital  notch,  will  serve  to  distinguish  a  right  from 
a  left  eye.  Artificial  eyes  should  be  removed  for  the  night  and  carefully 
washed.  Patients  soon  learn  to  insert  and  remove  the  "  eye  "  with  the 
greatest  ease.  The  method  of  insertion  is  as  follows  :  The  upper  lid 
having  been  raised  with  the  left  hand,  the  upper  edge  of  the  eye,  which 
is  held  in  the  right  hand,  is  inserted  under  the  upper  lid,  the  lower  lid  is 
then  drawn  down  with  the  left  hand  which  is  removed  from  above,  and 
the  eye  slips  into  place  ;  it  may  be  removed  by  insinuating  a  bent  hair-pin, 
or  head  of  a  pin,  under  the  lower  edge.  After  having  been  worn  for  a  year 
or  so,  the  surface  of  the  glass  gets  rough,  when  it  should  be  re-enamelled, 
otherwise  it  may  give  rise  to  irritation  and  cause  shrinking  of  the  socket. 
Owing  to  the  presence  of  a  slight  discharge,  the  socket  should  be  bathed 
daily  with  a  mild  astringent  lotion. 

The  reform  eyes  have  one  drawback,  namely  that  in  rare  cases  they 
break  spontaneously.  We  have  seen  two  instances  in  which  this  occurred  : 
the  patient  hears  a  sudden  snap,  and  when  the  eye  is  removed  a  small 
hole  is  seen  on  the  posterior  surface  and  the  chip  corresponding  to  it  is 
found  in  the  interior  of  the  eye.  The  eye  in  reality  collapses  owing  to 
the  diminished  air  pressure  in?ide  it.  Reform  eyes  can  be  made  with  a 
bulge  above  in  order  to  diminish  the  unsightly  hollow  which  sometimes 
exists  above  the  upper  lid  after  enucleation. 

Evisceration. — For  mode  of  performing  this  operation  vide  p.  147. 
Evisceration  is  not  held  to  be  so  good  a  safeguard  against  sympathetic 
ophthalmitis  as  excision,  and  is  not  employed  for  that  purpose,  unless 
quite  soon  after  the  injury.  The  advantage  of  evisceration  over  enuclea- 
tion lies  in  the  better  stump  provided  by  it  for  a  prothesis,  and  the 
consequent  better  cosmetic  effect. 

Mules'  Operation. — For  the  description  of  this  operation  see  p.  148. 
The  objections  to  and  advantages  of  this  operation  are  the  same  as  in 
evisceration,  but  it  gives  a  better  stump  than  the  latter. 

Therapeutic  Operations  used  in  Sympathetic  Ophthalmitis.— 

The  field  for  these  operations,  if  it  exist  at  al],  is  exceedingly  limited. 
Practically  the  only  indication  for  operative  interference,  in  the  active 
period  of  sympathetic  ophthalmitis,  is  long-continued  high  tension  ; 
and  in  the  foregoing  pages  the  warning  has  been  repeatedly  uttered, 
that  any  operative  meddling  with  the  iris  in  this  period  is  more 
apt  to  aggravate  the  process  than  to  alleviate  it ;  and  that,  even  if 
tension  be  relieved  by  an  iridectomy,  it  soon  becomes  high  again, 
owing  to  fresh  plastic  exudation. 


208  DISEASES    OF    THE   EYE.  [chap.  vii. 

Should  it  seem  imperatively  necessary  to  endeavour  to  reduce 
a  long-continued  high  tension,  sclerotomy  is  to  be  preferred  to 
iridectomy.  It  may  have  a  beneficial  effect,  and  is  not  likely  to  do 
harm.  It  can  be  repeated  more  than  once,  should  it  be  deemed 
necessary. 

Paracentesis  of  the  cornea  is  a  measure  which  can  be  used  as 
a  temporary  means  of  relief  for  high  tension,  and  it,  too,  may  be 
repeated. 

Optical  Operations  used  in  Sympathetic  Ophthalmitis.  —  The  object 
of  these  operations  is  to  provide  an  artificial  pupil  in  the  sympathising 
eye  after  all  inflammation,  or  tendency  to  it,  has  ceased,  in  order  to  improve, 
or  to  restore,  vision  which  is  interfered  with  by  closure  of  the  pupil.  Similar 
operations  may  be  indicated  occasionally  in  the  exciting  eye,  in  cases 
where  it  has  not  been  excised. 

The  cardinal  point  to  be  borne  in  mind,  it  may  again  be  stated,  is, 
that  these  operations  must  never  be  performed  until  six  months  at  least 
have  elapsed — and  a  longer  period  is  preferable — after  all  and  every 
tendency  to  inflammation,  or  irritation,  has  subsided.  Inattention  to 
this  rule  will  result  in  a  re-lighting  of  the  inflammation,  re-closure  of  the 
pupil  which  may  have  been  made,  or  intra-ocular  haemorrhage,  and  a 
long  period  of  waiting  before  any  further  operation  can  be  undertaken ; 
or  else  the  globes  may  become  shrunken,  and  all  hope  may  be  at  an  end. 

Moreover,  as,  even  under  the  most  favourable  conditions,  and  with 
the  most  skilful  operation,  inflammation  may  return,  or  intra-ocular 
haemorrhage  may  occur,  or  the  eye  may  become  phthisical,  no  operation 
should  be  done  unless  the  advantage  to  be  gained  from  it,  if  successful, 
promises  to  be  considerable. 

The  three  chief  operations,  one  or  other  of  which  may  be  applicable, 
are : — Iridectomy  or  Iridotomy,  extraction  of  the  clear  or  cataractous 
lens — for  the  lens  is  often  cataractous  from  interference  with  its  nutrition 
by  reason  of  the  irido-cyclitis — or,  discission  of  the  cataractous  lens. 

Iridectomy. — It  is  only  exceptionally  that  iridectomy  can  be  of  use, 
in  those  eyes  which  have  been  the  subjects  of  the  severer  plastic  uveitis, 
resulting  in  total  posterior  synechia.  In  these  cases,  the  tissue  of  the 
iris  has  undergone  such  extreme  degeneration,  that  it  is  impossible  to 
obtain  more  than  mere  shreds  of  the  membrane  with  the  forceps,  so  that 
a  satisfactory  coloboma  can  rarely  be  made,  besides  which  there  is  often 
a  dense  mass  of  fibro-plastic  tissue  (cyclitic  membrane)  behind,  and 
adherent  to,  the  iris,  irritation  of  which  lights  up  an  inflammatory  reaction, 
which  often  closes  the  coloboma. 

Iridectomy  is  indicated  in  those  cases  rather,  where  a  less  severe  form 
of  iritis  has  existed,  resulting  in  a  complete  ring  synechia  of  the  pupillary 
margin  only.  Here  a  wide  coloboma  may  often  be  made  satisfactorily. 
The  iris  should  be  seized  with  the  forceps  at  about  the  lesser  circle.  If 
seized  at  the  pupillary  margin,  the  intimate  adhesion  between  the  latter 
and  the  lens  capsule  may  cause  injury  to  the  capsule,  and  consequent 


CHAP.  VII.]  THE    WEAL   TRACT.  209 

traumatic  cataract.  Iridotomy  by  De  Wecker's  or  Ziegler's  methods,  or 
with  a  punch  (chap,  x.),  is  often  of  very  great  service  in  the  more  severe, 
cases. 

Extraction  of  the  Lens. — This  is  indicated,  if,  on  the  formation  of  a 
coloboma,  the  lens  be  found  to  be  cataractous,  in  those  cases  of  ring 
synechia  where  iridectomy  has  been  performed  and  the  coloboma  has 
closed  again  ;  and  in  practically  all  cases  of  total  posterior  synechia,  be 
the  lens  clear  or  opaque.  In  the  former  class  of  cases  the  ordinary  com- 
bined method  of  cataract  extraction  answers  the  purpose,  or  a  preliminary 
iridectomy  may  be  made  some  weeks  previously. 

Cases  of  total  posterior  synechia  require  a  procedure,  such  as  one  or 
other  of  the  following  : — 

WenzeVs  Method. — The  puncture,  counter  puncture,  and  incision  are 
the  same  as  in  an  ordinary  cataract  extraction,  but  the  knife  on  entering 
is  passed  through  cornea,  iris,  lens,  iris,  cornea.  The  lens  is  thus  delivered 
as  completely  as  possible,  and  out  of  the  membrane  composed  of  degener- 
ated iris,  retro-iridic  connective  tissue,  and  capsule,  a  V-shaped  piece  is 
cut  with  the  forceps-scissors.  The  traumatism  of  this  operation  is  great, 
and  not  every  globe  will  bear  it,  and  phthisis  bulbi  may  follow. 

Hirschherg'  s  Method. — An  incision  is  made  with  a  keratome  in  the 
lower  margin  of  the  cornea.  With  a  fine  capsule  forceps,  introduced 
into  the  pupil,  the  thickened  anterior  capsule  is  seized  and  drawn  away 
and,  by  inserting  a  spatula,  as  much  of  the  lens  as  possible  is  extracted. 
Some  weeks  later  the  pupillary  membrane,  composed  of  lenticular  remains, 
posterior  capsule,  and  inflammatory  products,  is  divided  with  a  cystotome. 
The  advantage  of  this  operation  is  that  the  iris  is  not  interfered  with. 

Discission. — This  operation  was  employed  by  the  late  Mr.  George 
Critchett  with  success,  in  some  cases  where  cataract  was  the  main  obstruc- 
tion to  sight.  A  discission  needle  is  passed,  by  a  boring  motion,  through 
the  lenticular  capsule  ;  another  needle  is  then  passed  in  close  to  the  first, 
and  by  separating  one  point  from  the  other  a  rent  is  made.  This  is  followed 
generally  by  the  escape  into  the  anterior  chamber  of  a  small  quantity  of 
cheesy  lens  matter,  which  becoines  gradually  absorbed,  and  in  the  course 
of  some  weeks  the  capsule  closes  again.  The  operation  has  to  be  repeated 
several  times  before  a  clear  pupil  is  obtained,  care  being  taken  that  all 
irritation  from  the  previous  operation  has  subsided  before  another  be 
undertaken.  The  chief  danger  in  this  operation  is  irritation  and  high 
tension,  from  swelling  of  the  lenticular  masses  in  the  disorganised  eye. 

Pathology. — In  spite  of  the  vast  amount  of  experimental  and  clinical 
work  which  has  been  done  in  this  direction,  the  pathology  of  sympathetic 
ophthalmitis  is  still  wrapt  in  mystery.  It  would  be  impossible  in  this 
book  to  discuss  even  briefly  the  various  theories  which  have  been  advanced 
to  explain  the  causation  of  this  disease  and  the  method  whereby  it  is 
transferred  to  the  sound  eye.  We  must  only  content  ourselves  with  a 
general  statement  indicative  of  the  lines  on  w^hich  research  is  proceeding 
at  the  present  time. 

The  microscopical  appearances  in  eyes  affected  with  sympathetic 
ophthalmitis  were  first  described  by  Fuchs,  who  also  contrasted  this  type 
of  inflammation  with  that  caused  by  the  usual  infective  micro-organisms. 

14 


210  DISEASES   OF   THE   EYE.  [chap.  vii. 


The  latter,  to  which  he  gave  the  name  of  Septic  Endophthahiiitis,  is  charac- 
terised by  the  presence  of  a  fibrino-plastic  exudation,  confined  chiefly 
to  the  surfaces  of  the  iris  and  ciUary  region,  which  exudation,  except  in 
acute  purulent  cases,  becomes  converted,  later  on,  into  a  dense  fibrous 
tissue,  enveloping  the  lens  and  adherent  to  the  iris  and  ciliary  body  (cyclitic 
membrane). 

Sympathetic  ophthalmitis,  on  the  otlier  hand,  consists  in  an  infiltration 
of  the  very  substance  of  the  whole  uveal  tract,  including  the  chorioid. 
In  the  early  stages  the  uveal  tract  becomes  infiltrated  with  lymphocytes 
and  plasma  cells,  while,  later  on,  localised  collections  of  endothelioid 
cells  appear  sometimes  associated  with  the  presence  of  giant  cells,  the 
whole  process  being  rather  suggestive  of  tubercle.  This  cellular  infiltration 
may  cause  great  thickening  of  the  whole  uveal  tract,  and  may  even  pene- 
trate the  sclera.  It  must  be  said  however  that  a  septic  endophthalmitis, 
in  varying  degrees  of  severity,  usually  accompanies  the  sympathetic  type 
of  inflammation,  and  further  a  typical  proliferating  uveitis  has  now  and 
then  been  observed  in  cases  of  so-called  idiopathic  uveitis  without  perfora- 
tion of  the  eye,  and  this  fact,  as  well  as  the  clinical  symptoms  and  progress 
of  such  cases,  suggests  the  idea  that  they  are  of  the  same  nature  as  true 
sympathetic  ophthalmitis. 

Pathogenesis. — The  oldest  theory,  which  attributed  the  origin  of  this 
disease  to  a  reflex  neurosis,  may  be  dismissed.  The  most  generally  received 
opinion  is  that  sympathetic  ophthalmitis  is  a  parasitic  affection,  although 
the  organism  supposed  to  be  accountable  for  it  still  remains  to  be  discovered. 
Assuming  that  it  is  a  parasitic  affection,  how  is  the  disease  transferred  to 
the  sound  eye  ?  By  some  the  view  is  still  maintained  that  the  micro- 
organisms make  their  way  directly  from  one  eye  to  the  other  along  the 
optic  nerves  (migratory  ophthalmitis  of  Deutschmann),  but  it  is  much  more 
likely  that  the  transmission  takes  place  indirectly  through  the  blood,  the 
organisms  or  their  toxins  gaining  admission  into  the  circulation.  It  has 
also  been  suggested  (Meller)  that  the  infection  is  endogenous  and  that  the 
micro-organisms  are  already  present  in  the  blood  at  the  time  of  the  injury 
to  the  first  eye. 

The  latest  attempt  at  an  explanation  is  that  of  Elschnig,  who  seeks 
to  prove  experimentally  that  sympathetic  ophthalmitis  is  an  anaphylactic 
phenomenon.  The  course  of  events  he  takes  to  be  as  follows  : — The 
breaking  down  of  the  cells  of  the  inflamed  uveal  tissue  in  the  injured  eye 
sets  free  an  albuminous  antigen  the  absorption  of  which  sensitises  not  only 
the  whole  organism  but  also  gives  rise  to  a  local  sensitisation  of  the  uveal 
tissue  in  the  second  eye  ;  any  irritation  of  this  eye  will  then  Hglit  up  an 
anaphylactic  reaction  in  the  form  of  a  uveitis. 

This  is  no  doubt  a  very  attractive  hypothesis,  but  it  is  open  to  several 
objections,  of  which  we  need  only  mention  a  few.  In  the  first  place,  it 
has  not  been  proved  that  auto-anaphylaxis  does  occur  in  human  beings,  or 
that  a  local  anaphylaxis  can  be  induced  in  one  eye  by  an  autogenous  antigen 
developed  in  the  other.  Besides,  admitting  even  that  the  second  eye  can 
be  sensitised  in  this  way,  some  kind  of  disturbing  element  is  required  to 
set  the  anaphylactic  reaction  going  in  it.  Elschnig  thinks  that  gastro- 
intestinal auto-intoxication  supplies  this  element,  and  that  this  is  proved 


CHAP.  VII.]  THE    UVEAL    TRACT.  21 


by  the  presence  of  iudicanuria,  in  patients  suffering  from  uveitis.  But 
this  is  a  view  which  requires  very  much  stronger  proofs  than  those  which 
have  been  advanced  in  its  favour  (see  p.  186). 

Interesting  observations  have  also  been  made  on  the  condition  of  the 
blood  of  patients  suffering  from  sympathetic  uveitis.  It  has  been  found 
that  there  is  an  increased  lymphocytosis,  the  number  of  the  large  mono- 
nuclear cells  in  particular  being  augmented,  and  on  account  of  the  resem- 
blance of  the  blood  picture  to  that  which  obtains  in  syphilis  it  has  even  been 
suggested  tliat  syni]mthoti('  ophthalmitis  may  be  caused  by  a  protozoon. 


Injuries  of  the  Uveal  Tract. 

Injuries  of  the  Iris. — Punctured  Wounds  of  the  cornea,  or  of  the 
corneo-scleral  margin,  frequently  implicate  the  iris,  but  rarely  do  so 
without  also  injuring  the  crystalline  lens  or  ciliary  body,  on  which 
then  the  chief  interest  centres,  as  being  the  organs  from  which  serious 
reaction  is  most  likely  to  emanate.  A  small  simple  incised  wound  of 
the  iris  is  not  of  great  importance,  for  inflammatory  reaction  is  not 
common,  and  any  extravasation  of  blood  at  the  seat  of  the  iris  wound, 
or  into 'the  anterior  chamber  (hyphaema)  becomes  absorbed,  while, 
in  most  cases,  the  functions  of  the  iris  will  probably  not  be  affected, 
nor  sight  endangered.  Nevertheless,  as  iritis  does  sometimes  occur, 
it  is  desirable  to  use  measures  calculated  to  prevent  it,  such  as 
atropine,  a  dressing,  and  rest  of  the  eye  and  general  system.  Even 
extensive  wounds  of  the  iris  are  not  often,  as  such,  associated  with 
serious  danger  to  the  eye,  although  the  loss  of  continuity  in  the  iris 
never  closes  up.  Where,  for  instance,  the  iris  is  cut  in  its  entire 
width  from  ciliary  margin  to  pupillary  margin,  the  permanent  result 
is  a  wide  coloboma,  the  margins  of  which  may  be  adherent  to  the 
corneal  wound.  When  the  iris  is  prolapsed  in  the  corneal  wound, 
it  is  only  possible  to  reduce  it,  if  the  case  be  seen  within  a  few  hours 
of  the  occurrence  of  the  accident.  If  this  cannot  be  effected,  it  is 
necessary  to  abscise  the  prolapsed  portion.  Incarceration  of  the 
iris  in  the  corneal  cicatrix  may  lead  to  secondary  glaucoma,  cystoid 
cicatrix,  secondary  septic  infection  of  the  iris,  etc. 

Foreign  Bodies  of  small  size,  such  as  bits  of  steel  or  iron,  may 
perforate  the  cornea  and  fasten  in  the  iris,  the  puncture  in  the 
cornea  closing  rapidly,  and  possibly  no  aqueous  humour  being  lost. 
It  is  necessary  always  to  remove  such  a  foreign  body  without  delay, 
although  for  some  time  it  may  cause  no  reaction.     An  iridectomy 


212  DISEASES    OF    THE    EYE.  [cHAr.  vii. 


should  be  done,  the  foreign  body  being  removed  along  with  the 
portion  of  iris  in  which  it  is  embedded. 

Bloivs  on  the  Eye  are  apt  to  cause,  in  addition  to  hemorrhage 
into  the  anterior  chamber  from  the  iris  or  from  the  canal  of  Schlemm, 
one  of  several  remarkable  lesions  of  the  iris,  namely  : — 

1.  IridodiaJijsis'^ — i.e.  separation  of  the  iris  from  its  attach- 
ment to  the  ciliary  body.  This  is  usually  accompanied  by  consider- 
able hyplnema.  As  much  as  one-half  of  the  circumference  of  the 
iris  may  be  involved  in  the  lesion  ;   or,  the  latter  may  be  so  small  as 

to  be  diagnosed  only    by  the   pre- 


sence of   the  resulting  small    fresh 


haemorrhage  near  the  ciliary  margin 
of  the  iris  ;  or,  after  this  has  be- 
come absorbed,  by  aid  of  light 
transmitted  to  the  eye  by  the 
ophthalmoscope,  when  not  alone 
the  physiological  pupil,  but  also 
Fig.  71.  the    minute     marginal     traumatic 

pupil  Avill  be  illuminated.  It  is 
rarely  that  there  is  more  than  one  dialysis.  In  certain  degrees  of  the 
detachment,  by  reason  of  the  sphincter  of  the  iris  having  lost  its 
fixed  point,  it  becomes  stretched  in  a  straight  line  (Fig.  71)  art  the 
part  corresponding  with  the  dialysis,  and  assumes  a  D  shape  ;  or,  if 
the  detachment  be  more  extensive,  the  pupil  becomes  kidney-shaped  ; 
or  the  detached  portion  may  entirely  cover  the  pupil.  The  detached 
portion,  too,  may  be  turned  on  itself  (anteflexion  of  the  iris),  the 
uveal  surface  being  to  the  front.  The  functions  of  the  eye  after 
such  an  injury,  even  when  extensive,  are  sometimes  but  little  dis- 
turbed, or  there  may  be  monocular  diplopia. 

It  is  stated  that  an  iridodialysis  does  not  become  re-attached  ;  but 
we  have  seen  a  very  minute  iridodialysis  heal,  and  another  such  case 
is  recorded.  The  lengthened  use  of  atropine  promotes  such  a  result, 
but  it  can  only  be  hoped  for  if  the  iridodialysis  be  not  extensive,  and 
if  the  case  be  seen  early. 

Iridodialysis  does  not  increase  in  extent  in  the  course  of  time, 
or  lead  to  further  mischief  in  the  eye. 

An  operation  for  the  remedy  of  iridodialysis  has  been  proposed  and 


i'ptj,  5td\i'(T£s,  a  separating. 


CHAP.  VII.]  THE    UVEAL    TRACT.  213 

successfully  performed  by  Chalmers  Jameson  as  follows  : — If  the  dialysis 
be  of  some  extent,  two  needles  each  carrying  a  suture  of  fine  silk-worm 
gut  are  used.  The  first  needle  is  passed  through  the  corneo-scleral 
margin  2  mm.  from  tlie  limbus,  into  tlie  anterior  chamber,  under  and 
through  tlie  torn  iris-margin,  of  which  less  than  I  mm.  is  taken  up,  and 
through  the  cornea.  The  needle  is  liberated  from  the  suture.  The  second 
needle  is  similarly  introduced  at  a  convenient  distance  from  the  first, 
according  to  the  dimension  of  the  dialysis.  An  incision  is  then  made  in 
the  corneo-scleral  margin  in  a  straight  line  between  the  points  of  entrance 
of  the  sutures,  leaving  a  short  bridge  of  scleral  tissue  between  those  points, 
and  the  ends  of  the  incision.  An  iris  hook  is  passed  into  the  anterior 
chamber  between  the  iris  and  cornea,  and  the  sutures  are  in  turn  carefully 
snared,  the  corneal  ends  drawn  out  of  the  cornea  into  the  anterior  chamber, 
and  out  through  the  corneo-scleral  incision,  thus  enabling  the  sutures  to 
be  tied  on  the  bridges  of  scleral  tissue  at  each  end  of  the  incision  without 
including  the  cornea.  The  sutures  when  tied  bring  the  torn  surface  of 
the  iris  in  contact  with  the  inside  of  the  linear  incision,  but  not  between 
its  lips,  and  re-attachment  of  the  iris  by  agglutination  of  the  corneo-scleral 
wound  is  thus  accomplished.  Where  the  dialysis  is  of  moderate  dimension, 
one  suture  only  is  needed  ;  but  where  two  are  required,  they  should  both 
be  introduced  into  the  iris  before  either  is  tied. 

2.  Retroflexion  of  the  Iris. — From  a  blow  on  the  eye,  the  whole,  or  more 
commonly  a  portion,  of  the  iris  in  its  entire  width  can  be  folded  back  on 
the  ciliary  processes,  giving  the  appearance  of  a  very  dilated  pupil,  or 
of  a  coloboma  produced  by  a  wide  and  peripheral  iridectomy.  In  a  true 
coloboma  the  ciliary  processes  would  be  easily  seen,  but  not  so  in  retro- 
flexion, for  the  processes,  being  covered  by  the  retroflexed  iris,  present  a 
smooth  surface.  A  slight  dislocation  of  the  lens  in  the  direction  away 
from  the  iris  lesion  is  often  observed.  Retroflexion  of  the  iris  cannot  be 
cured,  but  useful  vision  is  retained,  if  the  injury  be  uncomplicated. 

3.  Rupture  of  the  Sphincter  Iridis. — There  may  be  but  one  rupture,  or 
there  may  be  a  number  of  small  ruptures  distributed  round  the  pupil. 
They  show  themselves  as  small  triangular  gaps  in  the  pupillary  margin, 
their  bases  directed  towards  the  latter.  This  condition  is  also  incurable, 
and  some  permanent  disturbance  of  vision  due  to  the  mydriasis  results. 

4.  Dehiscence  of  the  Iris  between  the  pupillary  and  ciliary  margins. 
This  is  a  slit-like  rupture  of  the  iris,  which  runs  in  a  radial  direction  through 
the  whole  width  of  the  iris,  with  the  exception  of  the  sphincter.  The  diag- 
nosis sometimes  cannot  be  made  with  certainty  until,  after  a  few  days, 
the  blood-clot  covering  the  dehiscence  is  absorbed.  The  opening  may  be 
caused  to  close  by  the  use  of  a  miotic,  which,  by  contracting  the  sphincter, 
brings  the  edges  of  the  dehiscence  together. 

5.  Traumatic  Aniridia. — The  whole  iris  is  torn  from  its  ciliary  insertion, 
and  may  be  found  lying  in  the  anterior  chamber  or  under  the  conjunctiva, 
having  in  the  latter  case  passed  through  a  rent  at  the  corneo-scleral 
margin.  Not  only  does  the  anterior  chamber  contain  blood,  but  the 
vitreous  humour  is  often  infiltrated  with  haemorrhage.  When  the  extra- 
vasated  blood  has  become  sufficiently  absorbed,  the  absence  of  the  iris  will 
be  noted,  and  in  many  instances  the  ciliary  processes  will  be  visible.     If 


214  DISEASES   OF   THE   EYE.  [chap.  vii. 


these  latter  are  visible,  the  diagnosis  '  aniridia  '  can  be  definitely  made,  but 
cases  do  occur  in  which,  notwithstanding  the  absence  of  the  iris,  the  ciliary 
processes  are  not  visible,  owing  probably  to  changes  in  them  which  cause 
them  to  shrink.  Such  cases  then  are  difficult  to  distinguish  from  retro- 
flexion of  the  iris,  but  tlie  importance  of  the  diagnosis  is  not  great. 

6.  Traumatic  Mydriasis,  and  Miosis. — Of  these,  mydriasis  is 
the  more  common.  The  dilatation  is  of  medium  degree,  and  the 
pupil  is  usually  of  irregular  shape^oval,  pear-shaped,  or  more 
dilated  at  one  part  than  elsewhere — and  contracts  but  slightly,  or 
not  at  all,  to  light.  Paralysis  of  accommodation  usually  accom- 
panies traumatic  paralysis  of  the  sphincter  iridis.  The  mydriasis 
is  probably  the  result  of  concussion  of  the  delicate  nerve-endings  in 
the  sphincter  of  the  iris.  (See  above,  under  Rupture  of  the  Sphincter 
Iridis.)  Traumatic  mydriasis  may  recover  after  a  long  interval, 
but  in  most  instances  it  remains  as  a  permanent  defect,  with 
some  derangement  of  vision  due  to  it  and  to  the  paralysis  of 
accommodation. 

With  traumatic  miosis  there  is  apt  to  be  spasm  of  accommoda- 
tion, which  may  produce  apparent  myopia.  The  prognosis  is 
fairly  good. 

TreaUnent. — For  mydriasis,  protection  spectacles,  galvanism, 
and  eserine.     For  miosis,  atropine. 

Injuries  of  the  Ciliary  Body. — Punctured  Wounds,  and  Foreign 
Bodies  perforating  the  sclerotic  at  a  distance  of  about  5  mm.  around 
the  cornea,  are  almost  certain  to  implicate  the  ciliary  body.  If 
there  be  no  prolapse  of  the  ciliary  body,  nor  any  foreign  body  in  the 
interior  of  the  eye,  the  sclerotic  wound  may  heal  by  aid  of  a  bandage 
without  further  ill  results.  If  a  prolapse  of  the  ciliary  body  or  iris 
be  present,  it  is  to  be  abscised,  with  careful  aseptic  measures  ; 
and  if  the  sclerotic  wound  be  large,  it  may  be  thought  desirable  to 
unite  its  margins  with  sutures. 

Wounds  of  the  ciliary  body  are  apt  to  cause  cyclitis,  especially 
if  the  former  be  incarcerated  in  the  sclerotic  wound  in  healing,  for 
the  incarcerated  portion  is  liable  to  become  infected. 

*  Injuries  of  the  Chorioid.  Small  Foreign  Bodies  may  pierce  the 
sclerotic,  or  the  cornea  and  lens,  and  may  lodge  in  the  chorioid,  and, 
if  favourably  situated,  can  then  be  detected  with  the  ophthalmo- 
scope, and  always  by  the  Rontgen  rays  if  of  metal  (chap.  x.).  These 
foreign  bodies  require  operative  removal  by  the  magnet,  if  of  steel 


CHAP.  VII.]  THE    UVEAL    TRACT.  215 


or  iron  (chap,  x.)  ;  or,  if  the  foreign  body  cannot  be  extracted, 
the  eyeball  must  be  removed,  to  avert  sympathetic  ophthalmitis. 

Incised  Wounds  of  the  sclerotic  very  frequently  involve  the 
chorioid  (p.  170). 

Rupture  of  the  Chorioid  near  the  posterior  pole  of  the  eye  is 
often  produced  by  blows  on  the  eye,  and  is  seen  with  the  ophthal- 
moscope as  a  whitish-yellow  (the  colour  of  the  sclerotic)  crescent 
some  two  or  three  papilla-diameters  in  length,  and  about  one  papilla- 
diameter  distant  from  the  optic  entrance,  the  concavity  of  the 
crescent  being  directed  towards  the  latter.  Immediately  after 
the  accident,  extravasated  blood  sometimes  prevents  a  view  of 
the  rupture.  Some  chorioiditis  may  result ;  but,  w^hen  this  passes 
away,  good  vision  is  frequently  restored  and  maintained,  provided 
detachment  of  the  retina  does  not  ultimately  supervene  from  cica- 
tricial contraction  at  the  seat  of  the  rupture.  On  the  other  hand,  a 
scotoma  in  the  field  may  be  produced,  and  if  the  rupture  be  in  the 
region  of  the  macula  lutea,  serious  loss  of  sight  may  be  caused. 

Treatment. — Careful  protection  of  the  eye,  and  abstinence 
from  use  of  it,  with  dry  cupping  at  the  temple  for  three  weeks, 
or  until  it  may  be  assumed  that  all  inflammatory  tendency  has 
subsided. 

Blows  upon  the  eye  may  cause  Extravasation  of  Blood  in  the 
Chorioid.  If  small,  these  extravasations  do  not  extend  beyond  the 
chorioid.  But,  in  the  case  of  copious  extravasation,  the  haemorrhage 
is  poured  out  from  the  chorioidal  vessels  between  that  coat  and  the 
sclerotic,  lifting  and  bulging  forward  the  chorioid  ;  or  between  the 
chorioid  and  retina,  giving  rise  to  a  detachment  of  the  latter  ;  and 
if  the  retina  give  way  the  blood  is  poured  out  into  the  vitreous 
humour.  Should  there  be  no  vitreous  humour  opacity,  the  extra- 
vasations in  the  chorioid  can  be  seen  with  the  ophthalmoscope  as 
somewhat  indistinct  (owing  to  resulting  opacity  in  the  overlying 
retina)  small  red  spots,  or  large  round  red  spots,  darker  in  the  centre 
than  at  the  margin.  That  these  haemorrhages  are  in  the  chorioid 
can  be  recognised  from  the  fact  that  they  lie  behind  the  retinal 
vessels.  The  haemorrhages  become  slowly  absorbed,  and  after  a 
time,  provided  that  they  have  not  ruptured  the  retina,  useful  vision 
may  be  restored. 

Treatment. — Complete  rest  in  bed.     Atropine.     Bandage. 


21G  DISEASES   OF    THE   EYE.  [chap.  vii. 


New  Growths  of  the  Uveal  Tract. 

New  Growths  of  the  Iris. — Cysts  of  the  Iris.  Also  known  as  Cysts 
of  the  Anterior  Chamber. — These  vary  from  a  very  small  size  to  that  which 
would  fill  the  anterior  chamber.  They  may  have  either  serous  or  solid 
contents.  The  serous  form  is  occasionally  congenital,  but  in  the  majority 
of  cases  the  cyst  originates  in  epithelial  cells  from  the  cornea,  epidermis, 
etc.,  which  are  implanted  in  the  iris  on  the  occasion  of  a  penetrating  wound. 
The  cysts  with  solid  contents  (epidermoid  elements)  usually  have  their 
origin  in  an  eyelash  which  has  entered  the  anterior  chamber  by  occasion 
of  a  perforating  corneal  wound.  All  these  cysts  are  sources  of  serious 
danger  to  the  eye  (irido-chorioiditis,  glaucoma,  etc.),  and,  it  has  been 
stated,  may  even  be  the  cause  of  sympathetic  ophthalmitis,  and  hence 
their  removal  is  called  for.  This  can  be  effected  without  much  difficulty 
if  the  tumour  be  small,  but  if  it  have  attained  a  large  size,  and  become 
adherent  to  the  posterior  surface  of  the  cornea,  the  attempt  is  often  un- 
successful. A  long  incision  should  be  made  in  the  corneo-scleral  margin, 
and  the  cyst,  along  with  the  portion  of  iris  to  which  it  is  attached,  drawn 
out  and  cut  off. 

Solitary  Tubercle. — Solitary  tubercle  may  be  accompanied  by  a  few 
smaller  growths,  but  it  generally  begins  as  a  single  yellowish-white  tumour, 
often  without  iritis,  which  gradually  increases  in  size  until  it  may  fill  the 
anterior  chamber.  It  finally  involves  the  cornea,  which  it  perforates, 
forming  a  f ungating  mass,  and  this  subsequently  breaks  down,  leaving 
only  a  small  shrunken  globe  in  the  socket. 

Treatment. — Tuberculin  in  the  early  stages  ;  and,  if  perforation  should 
take  place,  excision  of  the  eyeball. 

Sarcoma. — The  iris  is  that  portion  of  the  uveal  tract  which  is  most 
rarely  affected  with  primary  sarcoma.  It  arises  usually  from  a  congenital 
pigmented  na3vus  of  the  iris,  and  is  commonly  a  melano-sarcoma  ;  but 
leuco-sarcoma  has  also  been  recorded.  As  the  tumour  increases  in  size, 
it  fills  the  anterior  chamber,  and  grows  backwards  into  the  ciliary  body 
and  into  the  canal  of  Schlemm.  It  is  not  usual  for  the  tumour  to  become 
extra-ocular  by  growing  through  at  the  corneo-scleral  margin,  as  does 
tubercle  of  the  iris.  Irritation  or  inflammatory  symptoms  are  not  often 
present  ;  and  secondary  glaucoma  does  not  come  on  until  a  late  stage, 
when  the  growth  has  filled  the  anterior  chamber,  or  involved  the  ciliary 
body  extensively.  But  care  must  be  exercised  in  making  a  diagnosis  ; 
we  have  had  under  observation  for  a  great  many  years  two  cases  of  small 
pigmented  tumours  in  the  angle  of  the  anterior  chamber  which  have 
shown  no  signs  of  growth.  Unless  the  tumour  increases  in  size  no  treat- 
ment is  necessary. 

Treatment. — Enucleation  of  the  eye  should  be  advised  as  soon  as  the 
diagnosis  of  sarcoma  of  the  iris  has  been  made.  When  the  sarcoma  is 
small,  there  is  naturally  a  desire  on  the  part  of  the  surgeon  to  save  the  eye, 
which  probably  has  full  vision,  by  excising  the  portion  of  iris  in  which 
the  growth  is  seated,  and  there  are  some  cases  on  record  in  which  this  was 
done,  and  where  no  recurrence  of  the  tumour  took  place.     But  in  adopting 


CHAP.  VII.]  THE    UVEAL   TRACT.  217 


this  conservative  method  there  is  serious  danger  ;  for  it  is  not  possible 
to  determine  clinically  whether  the  sarcomatous  growth  is  truly,  or  only 
apparently,  confined  to  the  limited  region  of  the  iris,  where  it  can  be  seen. 
Even  in  the  early  stages  of  many  cases  of  sarcoma  of  the  iris,  the  neoplasm 
invades  the  ligamentum  pectinatum,  the  canal  of  Schlemm  (Plate  IV. 
J'ig.  5),  or  the  ciliary  body  ;  so  that,  although  the  iris  tumour  be  thorouglily 
removed,  the  growth  reappears  in  the  eye  before  long,  while  in  the  mean- 
time risk  of  infection  of  the  general  system  has  been  run. 

Carcinoma. — A  few  cases  of  metastatic  carcinoma  of  the  iris  and  ciliary 
body  are  on  record,  with  the  breast  as  the  primary  seat  of  disease. 

Ophthalmia  Nodosa. — See  p.  80. 

New  Growths  of  the  Ciliary  Body. — Sarcoma  of  the  ciliary  body  is 
generally  pigmented,  and  often  passes  unobserved,  until  it  attains  con- 
siderable size  as  a  brown  mass,  which  was  at  first  concealed  from  view 
by  the  iris.  Occasionally  it  is  first  noticed  when  it  makes  its  appearance 
at  the  angle  of  the  anterior  chamber.  It  usually  also  grows  backwards 
into  the  chorioid,  and  runs  the  same  course  as  sarcoma  of  the  chorioid, 
but  in  rare  cases  extends  round  the  whole  ciliary  region  (ring  sarcoma) 
(Plate  IV.  Fig.  5).  Renioval  of  the  eyeball  should  be  urged,  but  is  often 
for  a  time  declined  by  the  patient,  as  sight  is  but  slightly  affected  in  the 
early  stages. 

Myosarcoma  originating  in  the  ciliary  muscle  has  been  observed  a  few 
times. 

Carcinoma. — Secondary  carcinoma  may  occur  in  the  ciliary  body  as 
in  the  iris  and  the  chorioid,  but  is  very  rare. 

New  Growths  of  the  Qhonovdi,— Sarcoma  is  by  far  the  most 
common  neoplasm  of  the  chorioid,  and  the  chorioid  is  the  most 
common  seat  of  ocular  sarcoma.  It  is  seen  at  all  times  of  life,  but 
most  frequently  between  the  ages  of  forty  and  sixty.  Both  melano- 
sarcoma  and  leuco-sarcoma  occur,  and  may  originate  in  any  part 
of  the  chorioid. 

If  seen  in  a  very  early  stage,  it  is  easily  recognised  from  its 
projecting  over  the  general  surface  of  the  fundus,  the  retina  lying 
closely  applied  to  it ;  but,  unless  it  be  in  the  region  of  the  macula 
lutea,  when  it  leads  to  a  central  scotoma,  it  may  not  cause  any 
serious  disturbance  of  vision,  and  hence  may  not  at  that  period 
be  brought  under  the  notice  of  the  surgeon.  The  diagnosis  from 
detachment  of  the  chorioid  at  this  stage  is  made  by  the  presence  in 
the  latter  condition  of  the  characteristic  chorioidal  vessels,  and  by 
the  peculiar  colour  of  the  chorioid.  Detachment  of  the  chorioid, 
too,  is  much  rarer  than  sarcoma. 

The  retina  is  at  first  closely  applied  to  the  surface  of  the  growth, 
but  soon  the  retina  becomes  detached  (Fig.  72)  by  reason  of  serous 


218 


DISEASES   OF    THE   EYE. 


[chap.    VII. 


Fig.  72. — Chorioidal  sarcoma 
springing  from  posterior  pole  of 
fmidus.  Complete  detachment  of 
retina.  Lens  pushed  forwards. 
Iris  pressed  against  posterior  sur- 
face of  cornea.  As  yet  no  cupping 
of  the  disc. 


exudation  from  the  chorioid  ;    and  this   may  be   accompanied    by 
opacity  in  the  vitreous  humour,   which  contributes  in  rendering 

the  diagnosis  w^ith  the  ophthal- 
moscope difficult  or  impossible. 
If  the  detachment  be  shallow^  and 
the  retina  translucent,  the  tumour 
may  still  sometimes  be  seen 
through  the  sub-retinal  fluid  by 
aid  of  strong  illumination  ;  and 
even  direct  sunlight  may  be  em- 
ployed in  some  such  cases.  Often 
the  detachment  commences  at  a 
part  of  the  fundus  not  imme- 
diately over  the  tumour,  but  some 
distance  removed  from  it.  Owing 
to  the  great,  and  often  sudden, 
defect  of  vision  which  comes  on 
in  this  stage,  we  very  commonly 
see  these  cases  now  for  the  first 
time.  The  history  of  the  case  may  aid  us ;  w-hile  the  absence 
of  the  more  usual  causes  of  detachment  of  the  retina  should  make 
us  suspicious  of  an  intra-ocular  tumour,  and  the  fundus  should 
be  carefully  examined,  with  dilated  pupil,  in  all  such  cases. 

At  this  and  at  later  stages,  Leber's,  or  other.  Sclerotic  Trans- 
illuminator  (Fig.  73,  J  size)  is  a  valuable  diagnostic  aid.  It  consists 
of  a  small  electric  lamp  (6),  w^hich  re- 
quires a  current  of  eight  to  ten  volts, 
enclosed  in  a  metal  jacket  {a).  The 
anterior  end  of  the  lamp  is  in  contact 
with  a  short  glass  rod  (c)  covered 
with  a  hard  rubber  sheath.  The  light 
of  the  lamp  is  transmitted  along  the 
glass  rod,  and  the  exposed  end  (d)  of 
the  latter  is  placed  on  the  sclerotic  of 
the  cocainised  eye,  in  a  dark  room. 
Then,  if  the  eye  be  normal,  or  even  if 
a  ripe  cataract  be  present,  the  pupil  lights  up  with  the  familiar 
red  glow  from  the  chorioid.  But  if,  internal  to  the  spot  at  which 
the  glass  rod  is  applied,  a  new  growth  be  present,  the  pupil  does  not 


Fig. 


CHAP.  VII.]  THE    UVEAL    TRACT.  219 

light  up — it  remains  dark.  By  slipping  the  rod  over  the  whole  of 
the  suspected  region,  or  as  much  of  it  as  can  be  reached,  or,  indeed, 
over  the  whole  exposed  sclerotic,  it  can  be  ascertained  whether  an 
intra-ocular  growth  be  present.  The  only  limitation  to  the  method 
is  in  those  cases  where  the  tumour  is  situated  much  behind  the 
equator,  a  region  in  which  the  rod  cannot  be  brought  in  contact  with 
the  sclerotic.  The  brightness  of  the  red  reflex  in  the  pupil  depends 
very  much  on  the  incidence  of  the  rays  passing  through  the  sclerotic, 
and  the  brightest  reflex  is  obtained  in  the  normal  eye  when  the  glass 
rod  is  placed  at  about  the  equator  of  the  eyeball.  The  observer 
should  look  at  the  pupil  from  the  direction  of  the  patient's  gaze, 
whether  this  be  straight  forward  or  to  one  side.  Non-pigmented 
tumours  do  not  interfere  with  illumination  of  the  pupil ;  nor  do 
opacities  in  the  cornea,  or  lens,  nor  even  a  ripe  senile  cataract. 
Inflammatory  opacities  in  the  vitreous  humour  do  not  interfere 
with  the  pupil-glow,  but  an  intra-ocular  haemorrhage  even  of  slight 
amount  does  so.  Diaphanoscopy  may  also  be  of  use  in  the 
diagnosis  ;  it  consists  in  covering  the  patient's  face  with  a  rubber 
mask,  leaving  only  two  holes  for  his  eyes,  and  transilluminating  the 
eye  with  an  electric  lamp  placed  in  the  mouth. 

Soon  the  intra-ocular  tension  increases.  This  makes  the  diagnosis 
again  more  easy  in  many  cases,  for  the  combination  of  detached 
retina  and  increased  tension  exists  only  with  intra-ocular  tumours. 
The  increased  tension  may  come  on  very  slowly,  and  without  ciliary 
neuralgia  ;  or  more  rapidly,  and  with  all  the  signs  and  symptoms 
of  acute  glaucoma.  Yet,  if  the  case  come  under  observation  now^ 
for  the  first  time,  the  diagnosis  may  be  by  no  means  easy,  should 
the  refracting  media  be  opaque  (as  always  in  acute  glaucoma),  and 
consequently  the  detachment  of  the  retina  concealed  from  view. 
Here,  again,  the  history  of  the  case  is  all  we  have  to  depend  on, 
especially  the  fact  of  the  patient  having  noticed  a  defect  at  one  side 
of  his  field  of  vision  previous  to  the  onset  of  glaucoma. 

In  the  next  stage  of  the  growth  it  perforates  the  cornea  or  sclerotic, 
and,  increasing  rapidly  in  size,  although  still  covered  with  conjunc- 
tiva, it  pushes  the  eyeball  to  one  side,  the  upper  lid  being  stretched 
tightly  over  the  whole.  On  raising  the  lid  the  tumour  is  seen  as  a 
bluish-grey  mass  with  irregular  surface.  The  conjunctiva  is  now 
soon  perforated,  and  the  surface  of  the  tumour  becomes  ulcerated, 
with  a  foul-smelling  discharge  and  occasional  haemorrhages.     The 


220  DISEASES   OF   THE   EYE.  [chap.  vii. 


tumour  gradually  invades  the  surrounding  skin  and  the  bones 
of  the  orbit,  and  by  extending  through  the  sphenoidal  fissure  and 
optic  foramen  reaches  the  l)ase  of  the  brain. 

Another,  and  less  common,  course  of  chorioidal  sarcoma,  is  that 
in  which,  without  first  perforating  the  cornea  or  sclerotic,  the  tumour 
sets  up  irido-cyclitis,  leading  to  phthisis  l)ulbi.  Cases  in  which 
sarcoma  of  the  chorioid  was  found  in  shrunken  eyeballs  have  given 
rise  to  the  view  that  such  eyeballs  are  prone  to  develop  sarcoma. 
While  it  is  possible  that  sarcoma  may  develop  in  a  shrunken  eyeball, 
it  is  tolerably  certain  that,  in  the  majority  of  the  cases  in  which  both 
diseases  are  present,  the  sarcoma  has  been  the  primary  disease, 
and  has  undergone  regressive  metamorphosis.  An  apparent  cure  is 
thus  produced,  but  in  cases  in  which  the  opportunity  of  sufficiently 
prolonged  observation  has  been  afforded,  the  growth  has  again 
become  progressive.     (See  also  glioma  of  the  retina,  chap,  xii.) 

It  is  in  cases  such  as  these  that  sarcoma  of  the  chorioid  occasion- 
ally gives  rise  to  sympathetic  ophthalmitis. 

It  is  usually  upon  the  neighbouring  tissues  of  the  eyeball 
becoming  involved  that  secondary  growths  begin  to  form  in  other 
organs,  the  one  most  prone  to  be  affected  being  the  liver.  The 
lungs,  stomach,  peritoneum,  spleen,  and  kidneys  may  all  be  attacked. 

Chorioidal  sarcoma  is  almost  always  primary,  but  it  has  been 
seen  a  few  times  as  a  metastatic  disease. 

Carcinoma. — This  is  extremely  rare,  and  the  cases  of  it  on  record, 
as  in  the  iris  and  ciHary  body,  were  all  of  metastatic  origin,  the  primary 
disease  being  in  the  breast.  It  is  not  possible  to  distinguish  chorioidal 
sarcoma  from  chorioidal  carcinoma  by  the  ophthalmoscope.  Other, 
but  rare  forms  of  tumour  of  the  chorioid,  are  : — Sarcoma  carcinomatosum, 
Osteo  sarcoma,  and  Lymphoma. 

Tubercle  appears  in  cases  of  acute  miliary  tuberculosis  as  round, 
slightly  prominent,  pale  yellowish  spots,  of  sizes  varying  from  0*5 
to  2*5  mm.  in  diameter,  situated  always  in  the  neighbourhood 
of  the  optic  papilla  and  macula  lutea,  and  unaccompanied  by 
pigmentary  or  other  chorioidal  changes.  There  may  be  but  one 
of  these  foci,  or  there  may  be  many  of  them.  When  they  occur, 
it  is,  as  a  rule,  in  a  late  stage  of  the  general  disease,  but  they  have 
occasionally  been  noted  long  before  its  appearance.  According  to 
Stephenson  they  are  found  in  50  percent,  of  the  cases  of  tubercular 
meningitis,   while  Marple  (who  used  the  electric  ophthalmoscope) 


CHAP.  viT.]  THE    UVEAL    TRACT.  221 

believes  that  the  percentage  is  much  higher.  In  obscure  cases  of 
the  general  disease,  the  ophthalmoscope  can  therefore  render 
valuable  diagnostic  aid  by  revealing  these  minute  growths  in  the 
chorioid. 

Very  rarely  does  a  tubercular  tumour  grow  in  the  chorioid  in 
cases  of  general  chronic  tuberculosis,  attaining  to  a  large  size,  and 
destroying  the  eye  similarly  as  does  sarcoma  or  carcinoma. 

In  young  children  it  may  be  impossible  to  diagnose  between  a 
tubercular  tumour  of  the  chorioid  and  a  glioma  of  the  retina  (chap, 
xii.).  Yet,  as  in  either  case  enucleation  is  indicated,  the  diagnosis 
is  not  of  great  clinical  importance. 

Treatment. — So  long  as,  in  cases  of  sarcoma  and  carcinoma,  the 
tumour  is  wholly  intra-ocular,  enucleation  of  the  eyeball  should  be 
performed,  and  may  be  done  with  fair  hopes  of  saving  the  patient's 
life,  if  the  disease  be  primary,  but  it  should  be  stated  that  even 
when  the  eye  is  removed  in  the  early  stage  metastasis  may  never- 
theless take  place.  When  the  orbital  tissues  have  become  involved, 
extirpation  of  all  the  contents  of  the  orbit,  and  even,  if  necessary, 
removal  of  portions  of  its  bony  walls,  ought  to  be  undertaken,  should 
the  general  health  permit,  in  order  to  rid  the  patient  of  his  loath- 
some disease  ;  although  the  probable  presence  of  secondary  growths 
elsewhere  renders  but  slight  the  prospect  of  saving  the  patient's  life. 

Cases  of  miliary  chorioidal  tubercle  do  not  call  for  direct 
treatment. 

In  cases  of  tubercular  tumour,  the  question  of  removal  of  the 
eyeball  must  depend  upon  the  general  state  of  the  patient ;  but, 
if  it  seem  probable  that  life  will  be  prolonged  until  after  the  ocular 
growth  would  have  become  extra-ocular,  removal  of  the  eye  should 
be  recommended. 

*  Other  Diseases  of  the  Chorioid. — Posterior  Staphyloma. — This 
condition  will  be  described  in  connection  with  myopia  (chap,  xvi.), 
which  is  its  almost  constant  cause. 


Detachment  of  the  Chorioid. — As  the  result  of  copious  loss  of  vitreous, 
during  operations,  or  from  injury,  detachment  of  the  chorioid  is  not  un- 
common, but  it  does  not  require  to  be  specially  diagnosed  in  these  instances, 
and  therefore  it  is  not  important  to  consider  it  further  here. 

Idiopathic  detachment  of  the  chorioid  is  extremely  rare.  Its  ophthal- 
moscopic appearances  are  apt  to  be  taken  at  first  sight  for  a  simple  detach- 
ment of  the  retina,  or  for  leuco-sarcoma  ;   but,  on  closer  inspection,  the 


222  DISEASES   OF    THE    EYE.  [chap.  vii. 

chorioidal  stroma  is  observed  to  lie  immediately  behind  the  detached  retina, 
and  its  vessels,  etc.,  are  seen  in  the  upright  image  by  aid  of  the  same  lens 
as  are  the  retinal  vessels.  The  chorioid  is  not  everywhere  detached,  but 
is  separated  from  the  sclerotic  in  several  different  places,  and  these 
detachments  are  seen  in  the  form  of  apparently  solid  hemispherical  pro- 
tuberances rising  abruptly  from  the  fundus  into  the  vitreous  humour.  In 
otlier  places  tlie  chorioid  is  in  contact  with  the  sclerotic,  although  in 
some  of  these  positions  there  may  be  detachment  of  the  retina  alone. 
The  vitreous  humour  is  more  or  less  opaque.  Vision  is  greatly  lowered  or 
quite  destroyed. 

It  is  probable  that  a  clironic  chorioido-rctinitis  has  been  an  antecedent 
condition  in  all  of  these  cases.  Indeed,  signs  of  old  retinitis  are  often 
present,  such  as  perivasculitis  and  connective  tissue  striation  ;  and  in  one 
case  retinitis  was  actually  observed  long  before  the  detachment  of  the 
chorioid  came  on.  Adhesions  between  the  chorioid  and  sclerotic  are 
formed  in  consequence  of  this  inflammation  ;  and  then  inflammatory 
exudation  takes  place  behind  the  chorioid,  and  separates  it  from  the 
sclerotic,  where  it  is  not  adherent  to  the  latter. 

The  process  ends  either  in  phthisis  bulbi,  in  consequence  of  vascular 
changes  and  disturbances  of  nutrition,  or  in  cure  to  a  certain  degree,  in  so 
far  as  by  absorption  of  some  of  the  exudation,  and  by  alteration  of  the 
remainder  of  it  into  connective  tissue,  a  return  of  the  chorioid  and  retina 
to  their  normal  position  is  rendered  possible  ;  but  even  then  restoration  of 
sight,  with  tissues  so  disorganised,  cannot  be  looked  for. 

Treatment  hitherto  seems  to  have  been  of  no  avail.  Probably  active 
mercurialisation  might  afford  the  best  chance  of  doing  good,  should  a  case 
come  under  notice. 

Fuchs  has  pointed  out  that  detachment  of  the  chorioid  occurs  in  a  good 
many  cases  of  cataract  extraction  some  days  after  the  operation,  although 
there  has  been  no  loss  of  vitreous,  and  also  in  some  cases  of  iridectomy. 
It  can  often  be  found  with  the  ophthalmoscope,  and  even  sometimes  with 
the  oblique  illumination,  in  those  cases  of  cataract  extraction  in  which  the 
anterior  chamber  has  not  formed,  or  in  which,  having  formed,  it  has  become 
empty  again.  It  is  mainly  after  iridectomy  for  chronic  simple  glaucoma 
that  chorioidal  detachment  lias  been  noticed.  It  has  also  been  observed 
after  trephine  operations.  The  probable  explanation  is,  that  a  slight 
aperture  of  communication  has  been  niade  between  the  anterior  chamber 
and  the  sub-chorioidal  space,  through  which  the  aqueous  humour  passes 
behind  the  chorioid.  With  the  re-establishment  of  the  anterior  chamber, 
the  chorioidal  detachment  goes  back,  and  the  prognosis  is  in  all  cases  good 
as  regards  vision. 

Central  Senile  Areolar  Atrophy  of  the  Chorioid. — This  is  not  a  very  rare 
disease  and  presents  the  appearance  of  a  white  patch,  often  of  considerabl? 
extent,  at  and  around  the  macular  region.  In  some  cases  a  haemorrhage 
in  the  chorioid  and  posterior  layers  of  the  retina  forms  the  starting-point 
of  the  disease.  The  retinal  functions  always  suffer  much  ;  for  an  absolute 
central  scotoma  is  produced,  which  renders  reading  and  writing  impossible, 
although  orientation  is  not  greatly  impeded,  as  the  periphery  of  the  field 
remains  intact. 


CRAP.  viT.]  THE    UVEAL    TRACT.  223 

Tlie  discovery  of  the  presence  of  this  disease,  after  a  eataract  has 
been  successfully  removed,  is  sometimes  a  source  of  intense  disappoint- 
ment both  to  patient  and  surgeon,  which  cannot  be  guarded  against, 
unless  the  condition  of  the  fundus  oculi  have  been  noted  while  the  cataract 
was  still  incipient. 

Treatment  is  of  no  avail,  but  absolute  rest  of  the  eyes  from  all  attempts 
at  near  work,  and  the  use  of  dark  protection  spectacles  are  important,  so 
that,  at  tlie  least,  the  advance  of  the  disease  may  not  be  promoted. 

■Malformations  of  the  Uveal  Tract. 

Malformations  of  the  Iris. — Corectopia  {Kop-n,  the  pupil ;  eKTowo?,  out  of 
position),  or  malposition  of  the  pupil.  The  pupil  sometimes  occupies  a 
position  farther  from  the  centre  of  the  iris  than  normally. 

Polycoria  {iro\v^,  many  ;  Kopii,  the  pupil). — Where  there  is  more  than 
one  pupil.  The  supernumerary  pupil  may  be  separated  by  only  a  small 
bridge  from  the  normal  pupil,  or  it  maybe  situated  very  near  the  periphery 
of  the  iris.     In  neither  case  has  it  a  special  sphincter. 

Persistent  Pupillarij  Membrane. — This  appears,  most  commonly, 
in  the  form  of  very  fine  threads  stretched  across  the  pupil.  They 
cannot  be  mistaken  for  posterior  synechi?e,  as  they  spring  from 
the  anterior  surface  of  the  iris  at  the  corona,  some  distance,  that 
is,  from  the  margin  of  the  pupil.  They  do  not  interfere  with  the 
motions  of  the  pupil,  nor  with  vision. 

Coloboma  {Ko\of36s,  maimed)  and  Irideremia  (  pt?,  the  iris  ;  Ip-qixla, 
want  of). — Coloboma,  partial  defect,  and  Irideremia  (or  Aniridia),  complete 
absence  of  the  iris,  have  been  shown  by  Treacher  Collins  to  be  due  to  a 
similar  cause — in  short,  that  they  are  different  degrees  of  one  and  the 
same  condition.     They  are  sometimes  hereditary. 

Before  the  iris  is  formed  in  the  foetus  there  exists — between  the  posterior 
surface  of  the  cornea  and  the  anterior  capsule  of  the  lens — the  anterior 
portion  of  the  fibro-vascular  sheath.  This  receives  its  blood-supply 
partly  from  the  ciliary  arteries,  and  partly  from  the  vessels  in  the  posterior 
fibro-vascular  sheath,  which  are  prolonged  round  the  sides  of  the  lens  to 
join  it.  The  cornea,  anterior  fibro-vascular  sheath,  and  lens  lie  in  close 
contact  with  each  other. 

The  iris  is  developed  by  growing  forwards  from  the  margin  of  the 
anterior  chamber,  and  in  so  doing  has  to  insinuate  itself  between  the 
cornea  and  anterior  fibro-vascular  sheath  on  the  one  hand,  and  the  lens 
on  the  other,  pushing  the  prolongation  from  the  posterior  fibro-vascular 
sheath  in  front  of  it.  The  anterior  fibro-vascular  sheath  subsequently 
becomes  the  pupillary  membrane,  of  which  portions  sometimes  persist 
(see  above). 

If  we  suppose  some  abnormal  adhesion  to  occur  between  the  cornea, 
anterior  fibro-vascular  sheath,  and  lens-capsule,  or  some  delay  in  their 
separation  at  the  whole  circvimference  of  the  future  anterior  chamber,  we 


224  DISEASES    OF    THE    EYE.  [chap.  vii. 


can  understand  how  a  mechanical  obstruction  to  any  growth  of  the  iris 
forwards  would  be  introduced,  resulting  in  complete  absence  of  the  iris, 
or  irideremia.  Irideremia  maybe  complete  or  partial.  In  the  latter  case 
it  may  be  the  inner  circle  only  which  is  wanting,  giving  the  pupil  the 
appearance  of  dilatation  with  atropine.  Where  the  entire  iris  is  absent 
the  ciliary  processes  can  be  seen  all  round.  The  condition  may  be  binocular. 
If  the  obstruction  be  confined  to  a  portion  only  of  the  anterior  chamber, 
the  corresponding  portion  only  of  the  iris  will  be  prevented  from  growing 
forwards,  and  the  result  will  be  one  or  more  congenital  colobomata. 

The  patients  suffer  chiefly  from  dazzling  by  light,  from  which  oitlior 
protection  or  stenopaeic  spectacles  afford  some  relief. 

Malformations  of  the  Chorloid. — Coloboma. — This  is  a  solution  of 
continuity  occurring  always  in  the  lower  part  of  the  chorioid,  and  usually 
associated  with  a  similar  defect  in  the  iris.  It  may  commence  at  the  ojDtic 
papilla,  and  involve  the  ciliary  body  also,  and  sometimes  the  sclerotic 
(chap,  vi.),  and  even  the  cr.ystalline  lens  may  have  a  corresponding  notch  ; 
or  it  may  not  extend  so  far  in  either  direction.  The  condition  is  recognised 
ophthalmoscopically  by  the  white  patch,  due  to  exposure  of  the  sclerotic 
where  the  chorioid  is  deficient.  Sometimes  the  retina  is  absent  over  the 
defect  in  the  chorioid.  a  circvimstance  v.hich  may  be  ascertained  by  the 
arrangement  of  the  retinal  vessels  ;  but,  even  if  it  be  present,  its  functions 
at  that  place  are  wanting,  and  a  defect  in  the  field  of  vision  exists.  Central 
vision  is  often  normal. 

Abnormalities  in  the  Colour  of  the  Iris. — The  greenish  discoloration  of 
the  iris  due  to  iritis  and  hyphsema,  has  been  already  alluded  to ;  a  similar 
discoloration  is  seen  in  some  cases  of  chronic  iridocyclitis  due  to  the  yellow 
colour  of  the  aqvieous  humour,  but  other  changes  in  colour,  congenital  or 
acquired,  also  occur. 

Heterochromia  is  the  term  applied  to  the  condition  in  which  the  iris  of 
each  eye  is  of  a  different  colour,  or  in  w'hich  patches  of  a  different  colour 
appear  in  the  iris  in  one  eye.  This  is  usually  a  congenital  anomaly.  Where 
the  tw^o  eyes  are  not  of  the  same  colour  it  has  been  noticed  in  many  cases 
that  the  eye  with  the  lighter  tint,  especially  if  blue,  is  prone  to  become 
affected  with  cyclitis,  and  to  develop  secondary  cataract. 

Ectropion  of  the  Uveal  Pigment,  in  which  the  brown  pigment  passes 
round  the  margin  of  the  pupil  on  to  the  anterior  surface  of  the  iris,  is  met 
with  as  a  congenital  defect,  and  also  in  some  cases  of  glaucoma  and  irido- 
cyclitis with  increased  intra  ocular  tension. 

Siderosis  is  a  peculiar  greenish-yellow  or  rusty  discoloration  of  the 
iris  caused  by  the  infiltration  of  the  tissues  of  the  eye  with  soluble  iron 
salts  resulting  from  the  oxidation  of  chips  of  iron  or  steel  which  found  their 
way  into  the  eye  as  the  result  of  an  accident,  and  had  lodged  in  it  for  a 
considerable  time. 

Albinismus,  or  defective  pigmentation  of  the  chorioid  and  iris. 
This  is  usually  accompanied  by  defective  pigmentation  of  the  hair 
of  the  body.  The  iris  has  a  pink  appearance,  due  to  reflection  of 
light  from  its  blood-vessels,  and  from  those  of  the  choroid,  and 


CHAP.  VII.]  THE    UVEAL   TRACT.  225 

with  the  ophthalmoscope  the  hitter  vessels  can  be  seen  down  to 
their  finest  branchings.  The  pupil  to  the  observer  is  red,  not  black. 
The  light  which  enters  the  eye,  not  being  partially  absorbed  by 
pigment,  causes  the  patient  much  dazzling,  and  high  degrees  of  the 
condition  are  usually  accompanied  by  nystagmus.  In  childhood  the 
albinismus  and  attendant  symptoms  are  more  marked  than  later  in 
life,  when  some  degree  of  pigmentation  usually  takes  place. 

Much  advantage  may  be  derived  in  many  of  these  cases  by  the 
use  of  stenopaeic  spectacles,  at  least  for  near  work.  Any  defect  of 
refraction  should  be  carefully  corrected,  in  order  to  give  the  patients 
the  best  possible  use  of  their  eyes. 

Operations  on  the  Iris. 

Iridectomy. — This  is  performed  for  optical  purposes,  in  zonular 
cataract,  corneal  opacities,  or  closed  pupil ;  to  reduce  abnormally 
high  intra-ocular  tension,  in  primary  and  secondary  glaucoma  ;  and 
for  the  removal  of  tumours  or  foreign  bodies  in  the  iris. 

The  instruments  required  are  a  spring  speculum  ;  a  fixation 
forceps,  with  spring  catch  (Fig.  78)  ;  a  lance-shaped  iridectomy 
knife  (keratome)  (Fig.  74),  or  a  Graefe's  cataract  knife  ;  a  bent  iris 
forceps  (Fig.  75),  or  a  Tyrrell's  hook  (Fig.  76)  ;  a  pair  of  iris  scissors 
curved  on  the  flat  (Fig.  77),  or  de  Wecker's  forceps-scissors  ;  and  a 
small  spatula. 

The  width  of  the  coloho^na  depends  a  good  deal  on  the  length  of 
the  corneal  incision,  for  it  cannot  be  wider  than  the  incision  is  long. 
Its  depth  depends  on  the  proximity  of  this  incision  to  the  corneo- 
scleral margin.  If  a  wide  and  very  peripheral  coloboma  be  desired, 
the  incision  must  be  long,  and  must  lie  actually  in  the  corneo-scleral 
margin  ;  the  iris  forceps  being  then  introduced,  a  portion  of  the  iris 
corresponding  with  the  length  of  the  incision  may  be  seized,  drawn 
out,  and  cut  off,  the  blades  of  the  scissors  being  applied  parallel 
and  close  to  the  incision,  and  by  this  means  a  coloboma,  as  at  Fig. 
79,  is  produced.  An  incision  somewhat  inside  the  corneal  margin 
will  give  a  pupil,  as  in  Fig.  80.  A  narrow  coloboma  (Fig.  81)  is 
obtained  by  making  a  short  corneal  incision,  which  may  be  more  or 
less  peripheral  as  circumstances  require  ;  by  taking  up  as  little  as 
possible  of  the  iris  in  the  forceps,  or  by  using  a  Tyrrell's  hook,  instead 
of  an  iris  forceps,  for  catching  and  drawing  out  the  iris  ;  and  by 
15 


226 


DISEASES   OF   THE   EYE. 


[chap.    VII, 


Fig.  74. 


Fig.  75. 


Fig.  76. 


Fig.  77. 


applying  the  blades  of  the  scissors  at  right  angles  to  the  incision  in 
the  corneal  margin. 

In  glaucoma  a  wide  and  very  peripheral  coloboma  is  required. 
For  optical  purposes  a  narrow  iridectomy  is  required,  because  with 
a  wide  coloboma  the  diffusion  of  light  may  be  very  troublesome  to 
the  patient. 


CHAP.    VII.] 


THE    UVEAL   TRACT. 


227 


The  best  position  for  an  iridectomy  for  glaucoma  is  in  the  upper 
quadrant  of  the  iris,  as  when  made  there  the  subsequent  dazzling 
by  light  and  the  disfigurement  are  least.     But  the  position,  by 


Fig.   78. 

preference,  for  an  optical  pupil  is  below  and  to  the  inside,  being  that 
most  nearly  in  the  direction  of  the  axis  of  vision.  If,  however,  this 
position  be  occupied  by  a  corneal  opacity,  the  coloboma  should  be 
made  directly  downwards  ;  or,  if  that  place  be  ineligible,  then 
downwards  and  outwards,  or  directly  outwards,  or  directly  in- 
wards. The  upward  positions  are  of  little  use  for  optical  pupils, 
owing  to  the  overhanging  of  the  upper  lid  ;  yet  it  often  happens 
that  we  have  no  other  choice. 

In  the  Performance  of  an  Iridectomy,  the  eye  should  be  fixed 
with  a  forceps  at  a  position  on  the  same  meridian  as  that  in  which 
the  coloboma  is  to  lie,  but  at  the  opposite  side  of  the  cornea,  and 
close  to  the  latter. 

The  point  of  the  lance-shaped  knife  is  then  entered  almost  per- 
pendicularly to  the  surface  of  the  cornea,  and  made  to  penetrate 
the  latter.  As  soon  as  the  point  of  the  blade  has  entered  the  anterior 
chamber,  the  handle  of  the  knife  is  lowered,  and  the  blade  is  passed 


Fig.  79. 


Fig.  80. 


Fig.  81. 


on  into  the  anterior  chamber  in  a  plane  parallel  to  the  surface  of  the 
iris,  until  the  incision  has  attained  the  required  length.  The  handle 
of  the  knife  is  now  lowered  still  more,  so  as  to  bring  the  point  of  the 
blade  almost  in  contact  with  the  posterior  surface  of  the  cornea,  in 
order  to  prevent  any  injury  to  the  lens  in  the  next  motion.  The 
knife  is  then  very  slowly  withdrawn  from  the  anterior  chamber. 


228  DISEASES   OF    THE   EYE.  [chap.  vii. 

At  the  same  time  the  aqueous  humour  Hows  oli'  slowly,  and  the 
crystalline  lens  and  iris  come  forwards. 

The  fixation  forceps  is  now  taken  over  by  the  assistant,  and  the 
closed  iris  forceps  is  passed  into  the  anterior  chamber,  its  points 
directed  towards  the  posterior  surface  of  the  cornea,  so  as  to  avoid 
engaging  them  in  the  iris.  When  the  pupillary  margin  has  been 
reached,  the  forceps  is  opened  as  widely  as  the  corneal  incision  will 
permit,  and  the  corresponding  portion  of  the  iris  is  seized  and  drawn 
out  to  its  full  extent  through  the  corneal  incision. 

With  the  scissors  held  in  the  other  hand  the  exposed  bit  of  iris 
is  snipped  off  quite  close  to  the  corneal  incision.  Care  should  now 
be  taken  that  the  angles  of  the  coloboma  do  not  remain  in  the  wound  ; 
and,  if  they  are  seen  to  do  so,  they  must  be  reposed  by  pushing  them 
into  their  places  gently  with  the  spatula. 

Iridotomy. — For  description  and  uses  of  this  operation  see 
chap.  X. 


CHAPTER    VIII. 

THE  PUPIL. 

The  movements  of  the  iris,  which  produce  contraction  and  dilatation 
of  the  pupil,  are  involuntary  and  are  governed  by  two  un striped 
muscles — namely,  the  sphincter  pupillse,  and  the  dilator  pupillae. 
The  sphincter  is  a  ring  of  muscle  situated  close  to  the  margin  of  the 
pupil  and  is  supplied  by  the  third  nerve,  while  the  dilator  is  a  thin 
muscular  layer,  of  which  the  fibres  are  arranged  radially,  and  which 
is  situated  near  the  posterior  surface  of  the  iris,  and  is  supplied  by 
the  sympathetic  nerve. 

These  muscles  are  set  in  motion  either  by  reflex  stimuli,  or  by 
what  Parsons  aptly  terms  synkinesis — i.e.,  by  association  with 
other  voluntary  or  involuntary  movements. 

Contraction  of  the  Pupil  is  brought  about  by  the  light  reflex,  or  by 
the  accommodation  synkinesis. 

The  Light  Reflex  depends  upon  the  transmission  of  the  stimulus 
from  the  retina,  by  the  afferent  path  (the  optic  nerve  and  tracts)  to 
the  pupil  constricting  centre  of  the  third  nerve  nucleus,  in  the  floor 
of  the  Aqueduct  of  Sylvius,  and  thence  by  the  efferent  third  nerve 
path  to  the  sphincter  pupillse.  As  regards  the  afferent  path,  it  has 
been  ascertained  that  the  optic  nerve  contains  fibres  of  two  different 
calibres,  coarse  and  fine,  of  which  one  set,  it  is  not  known  with  cer- 
tainty which,  are  visual  fibres  and  the  other  afferent  pupillo-con- 
strictor  fibres.  The  pupillary  fibres  undergo  partial  decussation 
in  the  optic  commissure,  and  pass  into  the  optic  tracts.  They  leave 
the  tract  before  it  reaches  the  external  geniculate  body,  but  at  what 
point,  and  their  further  route  to  the  third  nerve  nucleus,  are  not 
certainly  known.  It  is  on  the  whole  probable  that  the  path  taken 
is  by  the  superior  brachium  to  the  superior  quadrigeminal  body,  and 
thence  by  new  connections  to  the  third  nerve  nucleus  of  the  same 
and  of  the  opposite  side.  The  portion  of  the  third  nerve  nucleus 
which  gives  origin  to  the  pupillo-constrlctor  fibres  is  the  Edinger- 

229 


230  DISEASES   OF   THE  EYE.  [chap.  viii. 

Westphal  nucleus,  situated  in  the  median  part  of  the  main  nucleus. 
The  efferent  pupillo-constrictor  path  is  contained  in  the  trunk  of  the 
third  nerve.  In  the  orbit  the  pupillo-constricting  fibres  pass  into  the 
branch  which  supplies  the  inferior  oblique,  and  leave  it  again  by  the 
short  root  of  the  ciliary  ganglion.  From  this  ganglion  the  sphincter 
nerve  filaments — the  short  ciliary  nerves — pass  to  the  eyeball,  pierce 
the  sclerotic  around  the  optic  nerve,  and  pass  on  the  inner  surface  of 
the  sclerotic  to  the  iris.  The  innervation  of  the  ciliary  muscle  (the 
muscle  of  accommodation)  is  from  the  same  source. 

The  Accommodation  Synkinesis  is  contraction  of  the  pupil  associ- 
ated with  accommodation,  or  more  strictly  with  convergence  of  the 
optic  axes.  The  act  of  accommodation  of  the  eye  for  near  vision  is 
intimately  bound  up  with  the  act  of  convergence  of  the  optic  axis, 
which  takes  place  simultaneously  with  accommodation  (see  p.  6), 
and  it  can  be  shown,  that  if,  experimentally,  accommodation  and 
convergence  be  dissociated,  it  is  possible  to  accommodate  without 
producing  contraction  of  the  pupil,  but  not  to  converge  the  optic 
axes  without  that  synkinesis.  Hence  it  is  really  with  the  act  of 
convergence,  not  with  the  act  of  accommodation,  that  contraction 
of  the  pupil  is  associated.  The  object  of  this  contraction  is  to  cut 
off  rays  which  would  fall  on  the  peripheral  portions  of  the  lens, 
portions  which  are  not  curved  in  the  change  for  accommodation 
in  the  same  degree  as  is  the  centre  of  the  lens. 

Engorgement  of  the  bloodvessels  of  the  iris,  as  in  hypersemia,  or 
inflammation,  or  following  paracentesis  of  the  anterior  chamber,  is 
a  third  influence  which  causes  contraction  of  the  pupil. 

Dilatation  of  the  Pupil. — The  nerve  supply  of  the  dilator  pupillae 
is  from  the  cervical  sympathetic.  The  path  originates  near  the  third 
nerve  nucleus,  and  passes  through  the  medulla  to  a  region,  in  the 
upper  dorsal  and  lower  cervical  portion  of  the  lateral  column  of  the 
spinal  cord,  called  the  cilio-spinal  centre.  The  path  leaves  the  cord 
by  the  central  roots  of  the  first  three  thoracic  nerves,  and  thence,  by 
way  of  the  rami  communicantes,  passes  on  to  the  first  thoracic 
ganglion.  Thence  into  the  anterior  and  posterior  limbs  of  the  annu- 
lus  of  Vieussens  and  by  the  cervical  sympathetic  to  the  superior 
sympathetic  ganglion,  from  whence  the  path  enters  the  skull  by 
the  cervico-gasserian  fibres  to  reach  the  gasserian  ganglion.  From 
this  ganglion  it  passes  to  the  ophthalmic  division  of  the  fifth  nerve 
by  its  nasal  branch,  and  then,  leaving  it,  it  joins  the  long  ciliary 


CHAP.  VIII.]  THE  PUPIL.  231 

nerves  which  enter  the  eye  around  the  optic  nerve,  and  reach  the 
iris  by  passing  forwards  between  sclerotic  and  chorioid.  It  seems 
probable,  however,  that  all  the  dilating  fibres  do  not  run  to  the  eye 
by  way  of  the  cervical  sympathetic,  and  that  the  gasserian  ganglion 
receives  pupil-dilating  fibres  from  the  sympathetic  traversing  the 
cavum  tympani.  Dilatation  of  the  pupil  is  brought  about  by  the 
sensory  reflex,  or  by  the  cerebral  synkinesis. 

The  Sensory  Reflex  can  be  induced  by  almost  any  sensory  stimulus 
— e.g.,  the  prick  of  a  pin  or  a  pinch  on  the  neck,  galvanism  applied 
to  the  leg,  the  tickling  of  a  sensitive  place  in  the  region  of  the  fifth 
nerve  on  the  face,  etc.  Westphal  observed  dilatation  on  shouting 
loudly  into  the  ear  of  a  person  under  chloroform.  Schiff  and  Foa 
found  that  in  curarised  dogs  and  cats  a  dilatation  took  place  on  the 
application  of  every  stimulus,  not  necessarily  painful,  applied  to  the 
nerves  of  common  sensation  in  any  part  of  the  body.  Indeed,  it  is 
not  necessary  in  the  human  subject  that  the  stimulation  should  pro- 
duce any  sensation,  for  stimulation  of  the  skin  of  the  affected  side  in 
hemianaesthesia,  as  also  in  sleep  and  in  coma,  will  find  response  in 
dilatation  of  the  pupil.  The  afferent  impulses,  in  the  case  of  nerves 
of  common  sensation,  reach  the  cilio-spinal  centre  by  way  of  the 
posterior  spinal  columns. 

The  Cerebral  Synkinesis  is  induced  by  psychical  emotions.  The 
pupils  of  a  cat  in  anger  dilate,  and  those  of  a  frightened  child.  In 
sleep,  or  when  under  the  complete  influence  of  an  ansesthetic,  the 
pupils  are  contracted,  for  then  all  psychical  and  sensitive  stimuli 
are  reduced  to  a  minimum.  Facts  authorise  the  conclusion  that 
the  medium  dilatation  of  the  pupil  in  the  healthy  state  depends 
chiefly  on  the  intensity  of  these  stimuli,  habitually  transmitted 
through  the  sympathetic.  If  in  any  individual  they  be  slight,  his 
pupil  is  contracted  ;  if  intense,  it  is  dilated.  In  delicate,  nervous, 
excitable  people  the  pupils  are  often  much,  and  habitually,  dilated. 

In  addition  to  those  already  mentioned,  there  are  causes  for  the 
dilatation  of  the  pupil,  which  can  hardly  be  referred  to  simple  reflex 
action,  but  which  seem  to  be,  like  the  contraction  of  the  pupil  on 
convergence  of  the  visual  lines,  synkinetic  with  other  centres  in  the 
medulla  oblongata,  especially  with  those  for  respiration  and  uterine 
action.  With  every  deef  inspiration  or  expiration  a  considerable 
pupillary  dilatation  takes  place,  not  identical  with  that  slight  dilata- 
tion occurring  on  each  ordinary  inspiration,  and  depending  on  varia- 


232  DISEASES   OF    THE   EYE.  [chap.  viii. 


tion  of  blood  pressure,  but  due  to  simultaneous  stimulation  of  the 
respiratory  and  pupil-dilating  centres  by  retention  of  carbonic 
acid  gas  in  the  blood.  Marked  dilatation  at  the  beginning  of  each 
labour  pain  has  been  observed,  and  may  be  explained  as  an  associated 
action  of  the  neighbouring  centres  for  uterine  movements  and  pupil- 
dilatation. 

Hippus. — In  addition  to  the  normal  pupillary  motions  described  in 
the  foregoing,  and  visible  for  the  most  part  to  the  naked  eye  of  the  observer, 
there  is  a  phenomenon  of  pupillary  motion,  termed  hippus,  which  is 
discoverable  only  by  aid  of  a  corneal  microscope  or  loup,  consisting  in 
perpetual,  but  very  minute  and  irregular,  fluctuations  in  size  of  the  pupil. 
It  is  due  to  the  ever-varying  sensitive  and  psycliical  reflexes  which  are 
thus  constantly  manifesting  their  influences  on  the  pupil. 

The  Reflex  Mobility  of  the  Pupil  to  Light  is  tested  most  commonly 
for  the  purpose  of  deciding  the  existence  of  a  lesion  in  the  iris  itself 
(posterior  synechise)  or  in  the  efferent  path  (third  nerve).  The 
next  most  common  object  of  the  test,  is  to  determine  the  sensi- 
tiveness to  light  of  the  retina  or  of  the  visual  centre.  It  affords 
generally  a  sufficient  test  of  the  presence  or  absence  of  quantitative 
perception  of  light  :  but  the  latter  function  may  be  wanting  in 
certain  diseased  states,  and  yet  the  pupil-reflex  take  place,  but 
this  is  a  rare  condition  ;  or  the  pupil-reflex  may  be  wanting,- and 
still  perception  of  light  be  present.  AVhen  light  enters  into  the 
eye  the  pupil  of  that  eye  contracts  :  this  is  the  Direct  Reflex  Contrac- 
tion, but  owing  to  the  connection  between  the  two  third  nerve  nuclei 
the  pupil  of  the  unilluminated  eye  contracts  at  the  same  time,  and 
this  constitutes  the  Indirect  or  Consensual  Contraction.  The  test  is 
best  performed  in  diffuse  daylight,  with  the  patient's  face  directed 
towards  the  window,  a  distant  object  being  looked  at,  and  the  eye 
which  is  not  under  examination  being  carefully  excluded  from  the 
lioht.  The  surgeon  then,  having  observed  the  size  of  the  pupil  to 
be  examined,  excludes  the  eye  from  light  with  his  hand  for  some 
moments.  On  removing  the  excluding  hand,  a  normally  reacting 
pupil  will  be  found  to  have  become  dilated  ;  and  this  dilatation, 
after  an  interval  of  about  half  a  second,  will  be  observed  to  give 
way  to  an  extreme  contraction,  which  is  maintained  only  for  a 
moment,  and  is  then  succeeded  by  a  moderate  dilatation,  and  the 
pupil  then  again  contracts  somewhat,  and  so  on,  until,  after  some 
further  minute  oscillations,  it  comes  to  a  standstill.     The  explana- 


CHAP.  VIII.]  THE   PUPIL.  233 


tion  for  this  liippus  is  that  each  contraction  of  the  pupil,  by  diminish- 
ing the  supply  of  light  to  the  retina,  contains  in  itself  the  cause  of 
the  succeeding  dilatation  ;  and,  for  the  converse  reason,  each  dilata- 
tion sets  a-going  the  succeeding  contraction,  until  at  last  equilibrium 
is  attained.  A  comparison  between  the  maximum  of  dilatation  and 
maximum  of  contraction,  along  with  the  promptness  and  rapidity 
with  which  the  contraction  takes  place,  enables  the  observer  to 
form  an  estimate  of  the  activity  of  the  pupil-reflex.  In  performing 
this  test  it  is  important  that  the  patient's  gaze  should  be  fixed  all 
the  time  on  a  distant  object — hence,  unless  where  a  mere  trace  of 
perception  of  light  remains,  the  test  used  with  the  artificial  light 
is  not  so  reliable  as  that  with  daylight — so  that  the  accommodation 
synkinesis  may  not  vitiate  the  experiment.  The  consensual  reflex 
of  the  pupil,  as  well  as  the  direct,  should  always  be  tested — one  eye 
being  alternately  excluded  and  exposed,  the  motions  of  the  pupil  of 
the  other  eye  are  observed  and  compared  with  those  of  its  fellow. 
In  a  case  of  atrophy  of  one  optic  nerve,  say  the  left,  on  illuminating 
the  left  eye  no  movement  of  the  pupil  would  take  place  in  either 
eye,  but  on  throwing  light  into  the  right  eye  both  pupils  would  con- 
tract, the  right  directly  and  the  left  consensually.  In  examining 
the  pupils  we  have  also  to  decide  whether  they  are  of  equal  size  ; 
and,  in  order  to  avoid  error  through  posterior  synechise,  the  com- 
parison should  be  made,  with  both  eyes  open,  successively  in  two 
very  different  degrees  of  illumination.  Under  normal  conditions 
equality  in  size  of  the  pupils  will  exist,  with  both  eyes  open,  and 
there  will  be  only  a  slight  difference  if  one  eye  be  shaded  ;  for  the 
normal  consensual  pupil-reflex  is  not  quite  so  active  as  the  direct 
reflex.  If  the  pupils  be  found  of  different  sizes,  the  least  movable 
one  is  usually  the  pathological  pupil ;  but  this  question  is  often 
difficult  to  decide.  Finally,  it  should  be  noted  whether  the  direct 
pupil-reflex  is  similar  in  all  respects  in  each  eye.  For  the  Argyll 
Robertson  pupil  see  chap,  xiv.,  part  iii.,  and  for  Wernicke's  hemi- 
opic  pupillary  reflex  see  chap,  xiv..  Hemianopsia. 

Action  of  the  Mydriatics  on  the  Pupil.— Solution  of  sulphate 
of  atropine  dropped  into  the  conjunctival  sac  dilates  the  pupil, 
through  absorption  into  the  aqueous  humour.  For  it  has  been 
shown  that  the  aqueous  humour  of  an  eye  into  which  atropine 
has  been  instilled  acts  as  a  mydriatic  when  dropped  into  another 
eye.      It   is    evident    that    atropine    acts,    not    merely    by    para- 


234  DISEASES   OF    THE  EYE.  [chap.  viii. 

lysing  the  sphincter  pupillse,  but  also  by  stimulating  the  dilator, 
inasmuch  as  in  complete  paralysis  of  the  third  nerve  instillation  of 
atropine  produces  a  further  dilatation  of  the  pupil.  If  cocaine  be 
combined  with  atropine  in  the  solution,  or  if  it  be  dropped  in  as  a 
separate  collyrium,  a  further  dilatation  of  the  pupil  takes  place. 
Whether  this  is  to  be  referred  to  contraction  of  the  blood-vessels 
of  the  iris,  or  to  stimulation  of  the  sympathetic  supplying  the  dilator 
pupillcT,  is  not  clear.  Scopolamine,  homatropine,  ephedrine,  etc., 
act  similarly  to  atropine. 

Action  of  the  Miotics  on  the  Pupil.— These  drugs— of  which 
the  chief  are  Eserine  and  Pilocarpine — act  in  all  respects  as  the 
complete  antagonists  of  the  mydriatics,  by  stimulating  the  endings 
of  the  third  nerve  in  the  sphincter  pupillse.  Morphia,  taken  inter- 
nally or  used  hypodermically,  has  an  antagonistic  effect  to  atropine, 
when  it  is  absorbed  into  the  system,  and  is  employed  as  an 
antidote  in  cases  of  atropine  poisoning. 


CHAPTER   IX 

GLAUCOMA.i 

As  the  primary  cause  of  Glaucoma  remains,  to  a  great  extent, 
obscure,  it  cannot  well  be  included  under  the  heading  of  the  diseases 
of  some  definite  part  or  tissue  of  the  eye,  and  therefore  it  becomes 
necessary  to  assign  to  it  a  special  chapter. 

The  chief  and  essential  symptom  of  this  disease  is  Increased 
Intra-ocular  Tension — increased  hardness  of  the  eyeball — due  to 
over-fullness  of  the  globe.  All  the  other  symptoms  of  the  disease 
result  from  this  one. 

There  is  Primary  Glaucoma  and  Secondary  Glaucoma. 

In  primary  glaucoma,  the  increased  tension  comes  on  without 
any  previous  recognisable  disease  of  the  eye  ;  and  it  is  with  it  we 
have  mainly  to  do  in  this  chapter. 

In  secondary  glaucoma,  the  increased  tension  is  caused  by 
obvious  antecedent  disease  in  the  eye. 

Primary  Glaucoma. 

Primary  glaucoma  is  almost  invariably  a  binocular  disease.  Yet 
it  does  not  always  attack  each  eye  simultaneously,  indeed  it  is  more 
common  for  the  disease  to  appear  in  the  eyes  with  an  interval  of 
months,   or  longer. 

Of  primary  glaucoma  there  are,  clinically,  two  kinds — Chronic 
Simple  Glaucoma,  and  Congestive  Glaucoma  which  may  also  be 
acute  or  chronic.  But  these  different  clinical  varieties  of  glaucoma 
are  liable  to  run  into  each  other — chronic  simple  glaucoma  may 

1  From  yXauKos,  sea-green.  The  name  was  given  to  the  disease  by  the 
old  writers,  on  account  of  the  greenish  reflection  obtained  from  the  pupil 
in  some  cases.  But  this  greenish  reflection  is  seen  in  other  diseased  con- 
ditions, and  is  not  characteristic  of  glaucoma. 

235 


236 


DISEASES   OF   THE  EYE. 


[chap.   IX. 


become  congestive,  and  congestive  glaucoma  may  after  a  time  take 
on  the  chronic  simple  form. 

Increased  intra-ocular  tension,  as  stated,  is  the  chief  and  essen- 
tial symptom  of  glaucoma,  whatever  form  of  it  may  come  before 
us ;  although  this  increased  tension  may  not  always  be  present  in 
the  same  degree,  nor  at  every  hour  of  the  twenty-four. 

If  the  tips  of  the  index  fingers  be  placed  close  together  on  a 
normal  eyeball  (Fig.  82),  and  gentle  pressure  be  made  with  them 
alternately,  the  eyeball  will  be  felt  to  pit  slightly,  and  a  sensation 
of  fluctuation  is  given  to  the  fingers.  The  amount  of  this  pitting, 
or  fluctuation,  varies  according  to  the  de- 
■^^■■^H|^H  gree  to  which  the  eyeball  is  hlled  with  its 
^^^BV^I^B^^H  humours,  and  also,  to  some  extent,  accord- 
^^B^"      -J  ]^H       ^^^»  ^^  *^®  thickness  of  the  sclerotic  coat. 


is  harder  than  the  normal  globe,  because  it 


Fig. 


is  too  full. 

But   normal  eyes   may  have  a  tension 
below  or  above  the  average ;  and,  in  eyes  of 
the  latter  class,  it  is  occasionally  difficult  to 
decide  whether  or  not  the  tension  be  abnor- 
mally high.     If  it  be  a  question  of  one  eye  only,  then  a  comparison 
of  its  tension  with  that  of  its  fellow  decides  the   question,  for  the 
physiological  tension  is  always  the  same  in  each  eye. 

For  the  purposes  of  clinical  notation  certain  signs  have  been 
adopted.  Normal  tension  is  indicated  by  the  lettter  T,  or  Tn,  slight 
increase  of  tension  by  T  +  1,  still  higher  tension  by  T  +  2,  while 
T  +  3  denotes  stony  hardness  of  the  eyeball.  In  the  same  way 
diminished  tension  is  T  —  1,  T  —  2,  and  T  —  3.  T  +  ?  and  T  —  ? 
indicate  that  it  is  doubtful  whether  the  tension  be  slightly  above 
or  below  the  normal. 


Schiotz's  tonometer  is  a  most  valuable  instrument  for  estimating  tension  ; 
for  delicacy  and  accuracy  it  is  much  superior  to  the  digital  method,  which 
is  subject  to  more  sources  of  error.  The  instrument  (Fig.  83)  consists 
of:  (a)  A  perforated  cylinder  A  ending  in  a  footplate  D,  curved  to  adapt 
itself  to  the  surface  of  the  cornea.  This  cylinder  supports  (by  means  of 
the  arms  HH)  a  pointer  P  which  moves  on  the  scale  SS.  (6)  Sliding 
freely  in  the  cylinder  is  a  rod  or  stylet  B,  to  which  one  (W)  of  several  weights 
can  be  affixed  above  and  which  acts  on  the  pointer,  (c)  A  collar  C,  wliich 
runs  on  whool  bearings  on  the  cylinder  A,  is  provided  witli  two  L-sliaped 


CHAP.    IX.] 


GLAUCOMA. 


237 


projections  (F)  for  the  pui'pose  of  holding  the  instrument  in  the  vertical 
position. 

The  cornea  having  been  anaesthetised,  the  patient  is  placed  in  the 
recumbent  position  with  the  chin  slightly  raised,  so  that  the  instrument 
may  be  placed  vertically  on  the  cornea  (Fig.  84).  The  weighted  stylet  B 
produces  an  indentation  of  the  surface  of  the  cornea,  the  depth  of  which  is 
measured  by  the  movement  of  the  pointer  on  scale  SS.  The  lower  the 
tension  of  the  eye,  the  deeper  will  be  the  depression.  The  number  of 
divisions  of  the  scale  is  read  off,  begimiing  at  S  on  the  left,  and  note 
taken  of  the  weight  used,  then,  by  reference  to  a  chart  (Fig.  85)  which 


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130 


Fig.  83.  Tonometer 
of  Schiotz. 


Fig    84.     Tonometer  of 
Schiotz  in  use. 


11  10    8     8    7     6     S     4     3     2     1 
Deviations  of  Pointer 

Fig.   85.     Tonometer 
Chart. 


accompanies  the  instrument,  the  tension  in  millimetres  of  mercury  is 
found. 

In  using  the  instrument  it  is  important  to  observe  the  following  pre- 
cautions :  The  eyelids  must  not  touch  the  footplate,  which  should  be 
exactly  in  the  centre  of  the  cornea.  The  instrument  must  be  quite  vertical 
and  any  upward  or  downward  pressure  of  the  collar  C  must  be  avoided. 
The  stylet  must  be  kept  clean  (with  alcohol  or  ether)  so  as  to  avoid  friction 
as  much  as  possible.  The  most  reliable  results  are  obtained  by  using  a 
weight  which  wall  give  a  reading  between  2  and  6  on  the  scale. 

Pulsation  corresponding  to  the  pulse  rate  is  frequently  transmitted  to 
the  pointer  in  normal  as  well  as  in  glaucomatous  eyes.  The  continuous 
application  of  the  tonoineter  for  a  short  time  lowers  the  tension,  so  also 


238  DISEASES   OF    THE   EYE.  [chap.  ix. 


does  massage  of  the  eye.     Axenfeld  has  observed  a  decided  diminution  of 

the  tension  in  glaucoma  patients  when  under  chloroform,  except  in  cases 
of  very  high  tension,  and  he  suggests  that  the  absence  of  such  a  reduction 
in  the  tension  points  to  an  unfavourable  prognosis. 

Other  symptoms  of  glaucoma,  as  already  stated,  are  due  to  the 
increased  tension  ;  but  in  chronic  glaucoma  there  are  fewer  symptoms 
than  in  acute  glaucoma.  Let  us  now  describe  these  two  great  forms 
of  primary  glaucoma  separately. 

And  first  as  to  Chronic  Simple  Glaucoma  (also  known  as  Simple 
Glaucoma,  and  as  Chronic  Non-Congestive  Glaucoma). 

Symftoms. — Dimness  of  vision,  gradually  increasing,  in  the 
affected  eye,  is  the  only  symptom  of  which  the  patient  with  chronic 
simple  glaucoma  usually  complains.  But  some  patients  complain 
of  a  permanent  '  fog,'  which  yet  does  not  reduce  the  acuity  of 
vision  as  measured  with  the  test  types  ;  while  others  have  short 
attacks  of  '  fog '  associated  with  the  appearance  of  rainbow  colours 
around  the  flames  of  lamps  or  candles. 

The  tension  is  raised.  Sometimes  the  eye  is  very  hard  (T  -j-  2, 
or  more),  and  again  it  may  be  but  slightly  raised  (T  +  1).  Even  in 
one  and  the  same  eye  the  tension  usually  varies,  and  may  be  at 
one  time  too  high,  and  at  another  almost,  or  quite,  normal.  Hence 
it  may  be  necessary  to  test  the  tension  at  different  times  before 
a  decision  can  be  arrived  at. 

The  external  appearance  of  the  eye  is  usually  normal,  and  the 
pupil  reacts  well  to  light.  The  anterior  chamber  is  sometimes  a 
little  too  shallow. 

On  examination  wdth  the  ophthalmoscope,  the  optic  papilla  is 
found  to  be  cupped  ;  because  the  optic  disc,  or,  more  correctly,  the 
lamina  cribrosa,  being  the  weakest  part  of  the  sclerotic,  is  the  first 
place  to  give  way  to  increased  intra-ocular  tension.  Consequently, 
the  lamina  cribrosa  being  pushed  back,  the  optic  disc  becomes 
depressed,  or  cupped,  and  the  cup  becomes  sometimes  even  deeper 
than  the  outer  surface  of  the  sclerotic. 

This  cupping  of  the  papilla  (Plate  IV.)  is  a  most  important  sign 
of  glaucoma,  and  differs  essentially  in  appearance  from  the  physio- 
logical cupping  (p.  37),  inasmuch  as  it  occupies  the  entire  area 
of  the  papilla,  and  has  steep,  not  shelving  sides.  As  shown  in 
Plate  IV.  Fig.  4,  the  walls  of  the  excavation  are  often  hollowed 
out,  and  the  ophthalmoscopic  effect  of  this  is  to  give  to  the  retinal 


PLATE    IV 

{To  face  page  238) 

Fig,  1. — 'the  optic  disc  is  atrophied  and  greyish  white,  and  is  surrounded 
by  a  pale  ring,  the  glaucomatous  halo.  The  cupping  is  recognised  by 
the  curving  of  the  vessels,  where  they  dip  over  the  edge  of  the  cup, 
and  seem  to  end  abruptly,  as  well  as  by  the  paler  appearance,  and 
displacement  of  the  trunks  of  the  vessels  in  the  centre  of  the  cup. 

Fig.  2. — C,  cornea  ;  S,  sclerotic  ;  B,  ciliary  body,  atrophied  ;  I,  iris  ;  A, 
anterior  chamber  ;  L,  lens.  The  iris  is  adherent  to  the  cornea  from 
D  to  E. 

Fig.  3. — Letters  as  in  Fig.  2.     The  x  is  just  above  the  canal  of  Schlemm. 

Fig.  4. — N,  optic  nerve,  atrophied,  xx  pointing  to  the  only  remaining 
bundles  of  nerve  fibres.  S,  Sclerotic  ;  Ch,  chorioid  ;  R,  retina,  which 
was  partly  separated  in  making  the  section  ;  C,  deep  cup  ;  V,  a  vessel, 
with  some  others  containing  blood,  below  it. 

Fig.  6. — From  a  case  of  ring-sarcoma  of  the  ciliary  body.  Letters  as  in 
Fig.  2.  The  cornea  (C)  has  been  partly  cut  away,  x  points  to  canal 
of  Schlemm  and  tributary  vessels,  all  filled  with  pigment  cells.  I, 
extension  of  growth  into  iris. 

(For  the  micro-photos  of  sections  represented  by  Figs.  2  and  3 
we  are  indebted  to  the  kindness  of  Professor  O' Sullivan  and  Dr. 
Wigham  of  the  pathological  department  of  Trinity  College,  Dublin.) 


/ 


Plate  IV. 


Fig.   1.     Glaucomatous  Cup. 


Fig.  2.     Closure  of  Angle  of  Anterior 
Chamber  (Glaucoma). 


Fig.   3.     Angle  of  Anterior  Chamber 
in  a  Normal  Eye. 


Fig.  4.     Glaucomatous  Cup. 


Fig.  5.     Secondary  Glaucoma  with  open 

Angle,  but  obstructed  Canal  of 

Schlemm,  etc. 


CHAP.  IX.]  GLAUCOMA.  239 


vessels  the  appearance  of  being  broken  off  at  the  margin  of  the 
papilla  (Plate  IV.  Fig.  1),  where  they  pass  round  the  overhanging 
edge  of  the  excavation,  and  become  hidden  by  it,  while  on  the 
floor  of  the  excavation  they  reappear. 

The  presence  of  an  excavation  may  be  recognised  ophthal- 
moscopically,  in  the  examination  by  the  indirect  method,  by  means 
of  lateral  motions  of  the  convex  lens.  It  will  then  be  seen  that, 
while  the  whole  fundus  seems  to  move  along  with  the  motion  of  the 
lens,  the  floor  of  the  excavation  apparently  moves  in  the  same 
direction,  but  at  a  slower  rate.  This  parallax  is  the  more  marked 
the  deeper  the  excavation,  and  is  best  seen  by  observing  the  margin 
of  the  excavation.  The  phenomenon  is  explained  by  the  accom- 
panying figure  (Fig.  86).  If  o  be  the  optical  centre  of  the  lens 
being  used  in  the  examination,  and  b  and  a  two  points  lying  one 
behind  the  other,  the  inverted  images  of  these  points  will  be  situated 
at  h^  and  «>.     The  line  r/^  ¥  lies  in  the  visual  line  of  the  observer : 


Fig.   86. 

and  if  the  lens  be  moved  upward  a  very  little,  so  that  the  optical 
centre  comes  to  o^,  the  inverted  images  of  b  and  a  will  be  removed 
to  ¥  and  a^.  If  the  observer  have  not  altered  his  point  of  view, 
it  will  seem  to  him  that  the  point  b  has  made  a  more  extensive 
motion  than  the  point  a ;  or  that  it  has  moved  more  rapidly  than 
a,  and  has  glided  between  a  and  the  observer.  Short  and  rapid 
motions  of  the  lens  from  side  to  side,  or  from  above  downwards, 
will  best  show  the  parallax. 

In   examination   by   the    direct    ophthalmoscopic   method,    the 
existence  of  an  excavation  may  be  ascertained,  by  observing  that  a 


240  DISEASES   OF    THE  EYE.  [chap.  ix. 

lens  of  a  dilferent  power  is  required  in  order  to  obtain  a  clear  image 
of  the  margin  of  the  papilla  and  of  its  floor.  The  depth  of  the 
excavation  may  be  estimated  by  noting  the  difference  between  these 
two  lenses — e.g.  if  the  general  fundus  of  the  patient  be  emmetropic, 
and  the  emmetropic  observer  require  —  3  D  to  see  the  floor  of  the 
excavation,  the  depth  of  the  latter  is  about  1  mm.,  and  in  the  same 
proportion  up  to  10  D. 

Besides  being  cupped,  the  optic  papilla  in  glaucoma  becomes 
atrophied,  and  its  consequent  pallor  serves  to  aid  the  diagnosis 
between  this  and  a  physiological  excavation. 

If  primary  atrophy  should  attack  an  optic  nerve  in  the  disc  of  which 
there  is  a  physiological  cup,  the  appearance  presented  may  be  identical 
with  that  of  a  glaucomatous  cup,  and  the  diagnosis  would  then  depend 
upon  other  symptoms  of  each  disease.     (See  p.  242.) 

Spontaneous  pulsation  of  the  arteries  on  the  optic  papilla  may 
be  often  noted  in  glaucoma,  or  can  be  produced  by  slight  pressm-e 
on  the  eyeball  with  the  finger ;  because  blood  can  only  be  forced 
into  these  vessels  by  a  pressure  greater  than  that  opposed  to  it. 
Now%  in  an  eye  with  normal  tension  there  is  no  arterial  pulsation — 
and  slight  pressure  with  the  tip  of  the  finger  does  not  bring  it  on — 
for  the  arterial  tension  is  greater  than  the  intra-ocular  tension ;  and 
therefore  the  blood  flows  in  a  continuous  stream.  But,  in  the 
decidedly  glaucomatous  eye,  the  intra-ocular  tension  opposes  so 
great  an  obstacle  to  the  arterial  flow,  that  at  the  systole  alone  can 
it  make  its  way  through. 

Arterial  pulsation  also  occurs,  although  rarely,  in  exophthalmic  goitre 
(chap.  XX.)  ;  and  it  occurs  where  the  pressure  in  the  arteries  themselves 
is  low  (weak  heart  action,  aortic  regurgitation,  etc.),  even  though  that  in 
the  vitreous  chamber  be  normal. 

Around  the  margin  of  the  glaucomatous  excavation,  especially 
in  chronic  glaucoma,  one  usually  sees  the  whitish  appearance, 
termed  the  glaucomatous  ring  (Plate  IV.  Fig.  1),  which  is  held  to  be 
due  to  atrophy  of  the  chorioid  from  pressure. 

While  increasing  dimness  of  sight  is  the  symptom  of  which  the 
patient  chiefly  complains  in  a  case  of  chronic  simple  glaucoma,  an 
examination  of  the  field  of  vision  will  show  it  to  be  contracted — the 
contraction    of   the    colour-fields    preceding   that   for   white — (Fig. 


CHAP.    IX.] 


GLAUCOMA. 


241 


9)  in  consequence  of  interruption  to  tlie  conduction  in  the  retinal 
nerve-fibres  from  pressure  on  them  at  the  margin  of  the  depressed 
optic  papilla.     This  contraction  of  the  field  must  always  be  carefully 

Left  Field  Right  Field 


Fig.  87. — Case  of  Glaucoma.  Right  Field  (taken  with  perimeter)  con- 
tracted, especially  at  nasal  side,  so  close  up  to  fixation  point  that  operation 
was  contra-indicated.  V  =  6/36.  Left  Field,  as  taken  3^  years  after 
iridectomy,  contracted,  especially  at  nasal  side.  V  =  6/18.  No  further 
contraction  of  field  or  loss  of  vision  took  place  in  this  eye. 

looked  for  with  the  perimeter  in  eight  or  ten  meridians  as  it  is  most 

important  for  diagnosis  and  prognosis.     The  contraction  commences 

at  the  nasal  side   as   a   rule 

(Fig.   87),  while  at  the  same  20 

time  central  vision  is  lowered, 

and    at    a    later     stage    the 

temporal  portion  of  the  field 

becomes    contracted,    and 

gradually  complete   blindness 

is   brought    about.     In   some 

cases  the  field  projects  on  the 

nasal  side  above  or  below  the 

horizontal  line  (Fig.  88). 

In  addition  to  the  exam- 
ination of  the  field  with  the 
ordinary  perimeter,   the   field 

should  be  further  investigated  by  Bjerrum's  method  with  a  black 
velvet  screen  two    metres  square  and  a  test   object  about  2  mm. 
16 


fvmp^\ 


Fig.  88.     Glaucomatous  field  in  a 
late  stage  showing  nasal  "  step." 


242 


DISEASES   OF   THE   EYE. 


[chap.   IX. 


square  or  with  Priestley  Smith's  scotometer.  By  this  means  the 
state  of  relative  vision  within  the  field  is  examined.  In  glaucoma 
the  area  of  relative  defect  in  the  field  can  always  be  traced  to  the 
blind  spot,  if  a  sufficiently  small  test  object  be  used ;  or,  in  other 
words,  the  area  of  most  acute  vision,  and  that  of  relative  defect, 
meet  at  the  blind  spot.  In  some  cases  a  crescentic  para-central 
scotoma  which  includes  the  blind  spot  may  be  found. 

The  diagnosis  between  glaucoma  and  primary  atrophy  of  the 
optic  disc,  which  is  sometimes  difficult,  may  be  made  by  this  method 
of  examination  of  the  field  of  vision.  The  examination  of  the  field 
of  vision  by  the  ordinary  method  does  not  always  assist,  for  in  each  of 
these  diseases  the  field  is  liable  to  be  contracted.  Whereas  Bjerrum's 
symptom  occurs  with  glaucoma,  and  not  with  primary  atrophy. 

The  effect  of  a  miotic  on  the  intra-ocular  pressure  may  aid  the 
diagnosis  ;    for  while  it  would  not  materially  influence  the  normal 

tension     in     primary 
Riffhi  Field  atrophy,  it  would  re- 

duce the  high  tension 
in  glaucoma. 

The  central  colour 
sense  usually  remains 
normal  in  glaucoma 
until  a  late  stage, 
but  in  primary  optic 
atrophy  it  is  defective 
at  an  early  stage. 

Again,      if     slight 
pressure  with  the  tip 
of  the  surgeon's  finger 
during    the    ophthal- 
moscopic examination 
produce    arterial   pul- 
sation   at    the    optic 
papilla,  it  is  suggestive  of  glaucoma  ;  for  in  an  eye  with  normal 
tension,  as  already  stated,  considerable  pressure  is  needed  to  pro- 
duce this  effect. 

The  progress  of  chronic  simple  glaucoma  is  extremely  slow  and 
insidious,  extending  often  over  several  years,  and  ending  in  total 
blindness  if  untreated. 


lenip 


Fig.  89. — Case  of  Glaucoma.  Right  Field, 
taken  by  Bjerrum's  method.  The  contraction 
of  the  field  extends  to  the  blind  spot,  which  is 
situated  in  the  dotted  portion  of  the  figure. 


CHAP.  IX.]  GLAUCOMA.  243 

Acute  Glaucoma.  (Also  called  Acute  Congestive  Glaucoma.) — 
In  this  form  the  Increase  of  Tension  is  always  very  marked.  The 
following  symptoms  are  also  found  : — 

Diminished  Depth  of  the  Anterior  Chamber,  from  pushing  for- 
wards of  the  lens  and  iris. 

Diminution  of  the  Kefracting  Power  of  the  Eye,  by  reason  of  the 
nearer  approach  of  the  latter  to  a  globular  shape. 

Diminution  of  the  Amplitude  of  Accommodation,  and  Anaes- 
thesia of  the  Cornea,  owing  to  pressure  on  the  ciliary  nerves  as  they 
pass  along  the  inner  surface  of  the  sclerotic. 

Opacity  of  the  Cornea,  giving  its  surface  a  steamy  or  breathed- 
on  appearance,  due  to  oedema  of  the  corneal  tissue  and  epithe- 
lium. 

A  similar  appearance  is  seen  in  interstitial  keratitis. 

Indistinctness  of  the  Pattern  of  the  Iris,  similarly  due  to  oedema. 

Opacity  of  the  Aqueous  and  Vitreous  Humours. 

Dilatation  and  Immobility  of  the  Pupil,  the  result,  according  to 
some,  of  paralysis  of  the  ciliary  nerves,  but,  according  to  others,  of 
anaemia  of  the  iris  from  pressure  on  its  vessels.  The  pupil  is  often 
oval,  with  its  long  axis  vertical. 

The  Episcleral,  or  Anterior  Ciliary,  Veins  are  large  and  tortuous 
(Plate  II.  Fig.  4),  owing  to  pressure  on  the  ven^e  vorticosae,  w^hich 
prevents  the  outflow  by  those  channels  of  the  chorioidal  venous 
blood,  which  must  then  pass  off  by  the  anterior  ciliary  veins. 

Subjective  Appearances  of  Light  and  Colour,  and  coloured  halos 
or  rainbows  around  lamps  and  candles  (iridescent  vision)  are  com- 
plained of. 

Pain  is  a  very  marked  symptom  of  acute  glaucoma,  both  in 
the  eye  and  radiating  over  the  corresponding  side  of  the  head, 
and  is  often  very  violent ;  and,  in  consequence  of  the  pain  and 
of  the  injection  of  the  eyeball,  the  term  '  inflammatory '  is  some- 
times applied  to  congestive  glaucoma,  although  there  is  no  in- 
flammation in  the  true  sense. 

Vision  is  greatly  affected,  and  in  cases  of  some  standing  the  field 
of  vision,  when  it  can  be  examined,  will  be  found  contracted. 

The  Optic  Papilla,  when  the  media  are  sufficiently  clear  to  admit 
of  its  being  examined,  is  seen  to  be  cupped,  if  the  disease  have  con- 
tinued sufficiently  long  to  bring  about  this  change. 


244  DISEASES   OF   THE   EYE.  [chap.  ix. 

The  pain,  the  injection,  and  the  indistinctness  of  the  iris  stroma  may 
render  a  diagnosis  from  iritis  not  quite  plain  to  a  beginner  ;  and  an  error 
would  be  serious,  because  the  treatment  is  very  different.  In  iritis  the 
pupil  is  contracted  ;  in  acute  glaucoma  it  is  dilated  and  often  oval  from 
above  downwards.  In  iritis  there  are  usually  posterior  synechias  ;  in 
acute  glaucoma  there  are  none.  In  iritis  the  tension  is  nearly  always 
normal,  and  never  high,  while  in  acute  glaucoma  it  is  always  markedly 
raised.  In  iritis  the  anterior  chamber  is  of  normal  depth  ;  in  acute  glau- 
coma it  is  too  shallow. 

In  acute  glaucoma  we  recognise  certain  Premonitory  Symptoms — 
viz.  sudden  diminution  of  the  amplitude  of  accommodation,  evi- 
denced by  the  rapid  onset  or  increase  of  presbyopia,  and  the  con- 
sequent necessity  for  higher  +  glasses  for  near  work ;  and  the 
occasional  appearance  of  coloured  halos  around  the  flames  of  lamps 
or  candles,  with  attacks  of  fogginess  of  the  general  vision.  The 
duration  of  one  of  these  foggy  attacks  may  be  from  a  few  minutes  to 
several  hours.  Such  attacks  are  apt  to  occur  after  a  sleepless  night, 
or  after  a  meal,  and  are  sometimes  accompanied  by  peri-orbital 
pains.  Slight  opacity  of  the  aqueous  humour,  and  sluggishness  of 
the  pupil,  with  some  dilatation,  are  present  during  an  attack;  but 
the  eye  afterwards  returns  to  its  normal  condition,  and  remains  so 
for  weeks  or  months,  until  another  similar  attack  comes  on.  The 
premonitory  stage  may  last  a  year  or  longer,  but  cases  also  occur  in 
which  there  is  no  premonitory  stage. 

The  most  favourable  time  for  operative  interference  is  during 
this  premonitory  stage.  The  operation  can  then  be  performed 
with  technical  accuracy  in  an  eye  free  from  congestion,  and  w4th  a 
normally  deep  anterior  chamber.  There  is,  too,  as  yet  no  loss  of 
sight,  nor  any  degeneration  of  the  tissues  of  the  eyeball,  and  con- 
sequently the  operation  can  preserve  full  vision.  The  difficulty  is 
to  induce  patients  to  consent  to  operation  at  this  period. 

The  onset  of  the  True  Glaucomatous  Attack  is  usually  at  night. 
It  is  accompanied  by  violent  pain  radiating  through  the  head  from 
the  eye,  and  by  pericorneal  injection,  chemosis,  and  lacrimation. 
The  aqueous  humour  becomes  cloudy,  the  anterior  chamber  shallow, 
the  iris  discoloured,  and  the  pupil  dilated  to  medium  size  and  of 
oval  shape,  while  the  cornea  becomes  steamy  and  anaesthetic.  The 
patient  frequently  complains  of  subjective  sensations  of  light,  and 
vision  is  very  defective,  or  may  be  quite  wanting.  Vomiting  very 
frequently  accompanies  acute  glaucoma. 


CHAP.  IX.]  GLAUCOMA.  245 

The  latter  fact  leads  to  errors  of  diagnosis,  the  patient's  ailment  having 
been  taken  to  be  a  gastric  derangement,  while  the  ocular  symptoms  were 
regarded  as  mere  coincidences,  such  as  a  cold  in  the  eye,  neuralgia,  etc. 

An  attack  such  as  that  just  described  may,  to  a  great  extent, 
pass  away  in  the  course  of  a  few  days,  but  a  complete  remission 
of  all  the  symptoms  does  not  again  take  place.  Some  defect  of 
central  vision  is  left,  or,  it  may  be,  some  slight  peripheral  defect  in 
the  field  of  vision  ;  the  tension  does  not  become  quite  normal  again, 
and  the  pupillary  motions  remain  slightly  sluggish.  Another  acute 
attack  of  glaucoma  comes  on  in  the  course  of  some  weeks  or  months, 
and  it,  too,  may  pass  away,  leaving  the  eye  in  a  worse  condition  than 
it  found  it.  The  attacks  gradually  become  more  frequent ;  and  if 
in  the  intervals  the  eye  be  examined,  the  cornea  and  vitreous  humour 
will  be  found  more  or  less  opaque,  the  optic  papilla  cupped,  and 
pulsation  of  the  central  artery  of  the  retina  may  be  discovered. 
Finally,  there  is  no  remission  from  the  attack,  the  violent  glauco- 
matous symptoms  become  permanent,  and  all  vision  is  for  ever 
destroyed. 

Even  when  vision  has  been  destroyed,  the  high  tension  con- 
tinues, and  gradually  produces  that  disorganisation  of  the  tissues 
of  the  eyeball  known  as  glaucomatous  degeneration.  The  iris 
becomes  atrophied,  the  lens  becomes  opaque,  and  the  cornea 
frequently  ulcerates,  while  hsemorrhages  are  apt  to  occur  in  the 
anterior  chamber.  In  time  the  excessive  intra-ocular  tension  causes 
staphylomatous  bulging  of  the  sclerotic  in  the  ciliary  region,  or 
farther  back ;  and  finally,  these  eyes  may  become  the  subjects 
of  acute  purulent  chorioiditis,  ending  in  phthisis  bulbi. 

Acute  glaucoma  almost  always  comes  on  in  both  eyes,  either 
at  the  same  time,  or  with  an  interval,  it  may  be  of  weeks,  or  of 
months. 

The  reason  for  the  marked  difference  between  the  symptoms 
and  course  of  chronic  and  of  acute  glaucoma  is,  probably,  that  in 
the  former  the  increase  of  tension  is  very  gradual,  and  therefore 
the  eye  gradually  becomes  accustomed  to  it ;  while  in  acute  glau- 
coma the  increase  is  rapid  or  sudden,  and  the  circulation  of  the  eye 
has  not  time  to  accommodate  itself  to  the  new  state  of  things. 

Glaucoma  Fulminans  is  the  term  given  to  a  form  of  the  disease, 
which  is  more  acute  than  the  ordinary  acute  glaucoma  just  described. 
It  has  no  premonitory  stage,  and,  coming  on  with  all  the  symptoms 


246  DISEASES   OF    THE   EYE.  [chap.  ix. 

of  acute  glaucoma  greatly  intensified,  does  not  remit,  and  causes 
complete  permanent  destruction  of  vision  in  the  course  of  a  few 
liours.     It  is  very  rare. 

Subacute  Glaucoma. — This  form  differs  from  acute  glaucoma, 
in  that  its  premonitory  stage  merges  gradually  into  the  actual 
disease,  without  the  occurrence  of  an  acute  attack.  The  eye  gradu- 
ally becomes  hard,  the  pupil  dilated,  the  anterior  chamber  shallow, 
the  aqueous  humour  opaque  ;  while  the  cornea  is  '  steamy '  and 
aUcTsthetic,  and  the  episcleral  veins  are  distended.  With  the  ophthal- 
moscope the  cupped  disc  and  pulsating  arteries  may  be  seen, 
when  the  opacities  of  the  media  permit.  Vision  sinks,  and  the 
field  is  contracted  towards  its  nasal  side.  The  progress  of  the  disease 
is  very  slow  ;  and  in  its  course  attacks  of  ciliary  neuralgia,  with 
greater  increase  of  the  tension,  greater  opacity  of  the  aqueous 
humour,  increase  of  the  corneal  opacity  and  anaesthesia,  and  in- 
creased dimness  of  vision,  are  experienced.  These  attacks  pass  ofi 
in  the  course  of  a  few  days  or  hours,  leaving  the  eye  harder  and 
blinder  than  before.  The  subacute  glaucoma  sometimes  takes  on 
the  acute  form.  It  is  liable  to  bring  about  the  same  glaucomatous 
degeneration  of  the  eye  as  does  the  latter. 

Etiology  of  Glaucoma. — Glaucoma  is  a  disease  of  advanced  life, 
occurring  most  usually  after  fifty  years  of  age,  and  rarely  und«r  the 
thirtieth  year.  It  is  sometimes  hereditary,  and  may  then  make 
its  appearance  at  an  earlier  age  in  the  succeeding  generations.  My- 
opic eyes  are  less  liable  to  it  than  hypermetropic,  or  emmetropic 
eyes.  The  congestive  forms  are  more  common  in  women  than  in 
men. 

Anxiety,  sorrow,  and  influences  in  general  which  depress  the 
spirits  have  often  been  noticed  to  precede  the  onset  of  acute  glau- 
coma. Causes  which  tend  to  dilatation  of  the  pupil  may  also  pre- 
cipitate an  attack. 

Pathology  of  Glaucoma. — The  theory  of  this  disease  which  obtains 
very  general  acceptation  is  known  as  the  Retention  Theory. 

In  the  normal  eye  the  intra-ocular  fluids  are  being  constantly 
renewed,  and  they  must  as  constantly  escape  from  the  eyeball.  Their 
exit  is  mainly  by  way  of  the  sinus  venosus,  or  canal  of  Schlemm, 
situated  in  the  angle  of  the  anterior  chamber  (anterior  way  of  exit). 
The  spaces  of  fontana  are  separated  from  the  sinus  venosus  by  a 
delicate  wall  which  consists  of  a  layer  of  endothelium  only.     Again, 


CHAP.  IX.]  GLAUCOMA.  247 


the  intimate  union  of  the  distal  aspect  of  the  blood-vessel  with  the 
tissue  of  the  sclerotic  keeps  it  patent,  and  in  this  way  the  constant 
outflow  of  the  fluids  is  assured.  Hence  the  most  favourable  ana- 
tomical conditions  for  filtration  are  present  at  the  angle  of  the 
anterior  chamber.  Moreover,  physiological  experiment  has  shown 
that  the  intra-ocular  fluids  do  escape  by  this  path.  It  is  true  that 
the  aqueous  humour  and  other  intra-ocular  fluids  escape,  also, 
through  the  veins  on  the  anterior  surface  of  the  iris,  and  through 
the  veins  of  the  ciliary  body,  into  the  venae  vorticosse  (posterior 
ways  of  exit)  ;  but  it  is  tolerably  certain  that  the  main  exit  is 
through  the  canal  of  Schlemm,  at  the  angle  of  the  anterior  chamber. 

Now,  it  has  been  ascertained  that,  in  glaucomatous  eyes,  the 
root  of  the  iris  is  pushed  forwards,  and  lies  in  close  contact  with  the 
periphery  of  the  cornea  ;  thus  effectually  sealing  the  angle  of  the 
anterior  chamber  (Plate  IV.  Fig.  2),  so  that  no  fluid  can  escape 
through  the  spaces  of  fontana  and  canal  of  Schlemm.  The  intra- 
ocular fluids  must  then  be  retained  in  the  eye,  and  its  tension 
must  be  increased  ;  or,  in  other  words,  it  must  become  harder 
than  it  is  normally.  But  what  the  factor  is  which  brings  about 
the  peripheral  adhesion  of  the  iris  is  an  obscure  question  on  which 
opinions  are  divided. 

Priestley  Smith  is  of  opinion  that  the  chief  predisposing  cause 
of  primary  glaucoma  is  an  insufficient  space — the  circumlental 
space — between  the  margin  of  the  lens  and  the  structures  which 
surround  it,  and  to  the  progressive  increase  in  the  size  of  the  lens, 
which  he  has  shown  to  occur  as  life  advances,  he  attributes  the 
greater  liability  of  elderly  people  to  glaucoma. 

In  eyes  in  which  the  circumlental  space  is  insufficient,  by  reason 
either  of  the  original  structure  of  the  eye  (and  small  eyeballs  are 
specially  liable  to  primary  glaucoma,  a  fact  often  demonstrated  by 
the  small  size  of  the  cornea  in  the  eyes  attacked)  or  of  the  enlarge- 
ment of  the  lens,  any  condition  which  tends  to  overfill  the  veins  of 
the  head  and  uveal  tract  may  initiate  an  attack  of  acute  glaucoma, 
as  follows  : — 

An  increase  in  the  amount  of  blood  in  the  uveal  tract  must  be 
compensated  by  the  expulsion  of  some  other  fluid  from  the  eye  ; 
consequently,  the  aqueous  humour  filters  out  more  rapidly  than  is 
normal  at  the  angle  of  the  anterior  chamber.  As  the  contents  of 
the  chamber  diminish,  the  lens  and  iris  move  forwards  towards  the 


248  DISEASES    OF    THE   EYE.  [chap.  ix. 

cornea.  Now,  in  the  normal  eye,  and  especially  in  the  youthful  eye, 
this  compensation  is  effected  without  danger  to  the  angle  of  the 
anterior  chamber,  because  the  lens  is  comparatively  small,  the 
circumlental  space  large,  and  the  anterior  chamber  deep.  But, 
when  the  lens  and  ciliary  processes  are  already  in  close  relation  to 
each  other,  and  the  anterior  chamber  is  already  shallow,  then  any 
increased  fullness  of  the  uveal  tract  involves  danger  to  the  angle  of 
the  chamber.  The  turgid  ciliary  processes  find  insufficient  space 
for  their  expansion  ;  they  are  carried  forwards  together  with  the 
lens,  and,  pressing  upon  the  base  of  the  iris,  lock  up  the  angle  of  the 
anterior  chamber.  Thereupon,  the  further  escape  of  fluid  being 
impossible,  high  tension  of  the  eyeball  is  established. 

According  to  this  explanation,  then,  the  high  tension  is  due  to 
impeded  escape  of  the  intra-ocular  fluid  (the  retention  theory),  and 
depends,  primarily,  upon  an  increase  in  the  amount  of  blood  in 
the  eye.  Priestley  Smith  considers  that,  in  chronic  simple  glaucoma, 
the  predisposing  causes  are  the  same  as  in  acute  glaucoma  ;  but 
that  in  the  former,  the  vascular  disturbance  being  gradual  and 
slight,  the  vessels  adapt  themselves  to  the  slowly  increasing 
pressure,  and  the  angle  of  the  anterior  chamber  is  more  or  less 
compressed,  but  not  tightly  closed. 

Thomson  Henderson  has  advanced  a  theory  of  glaucoma  very 
different  from  that  generally  held.  There  are,  he  believes,  two  factors 
in  glaucoma  : — a  constant  predisposing  one — namely,  sclerosis  of 
the  ligamentum  pectinatum,  preventing  access  of  the  aqueous 
to  the  canal  of  Schlemm,  the  chief  normal  outflow  of  the  aqueous — 
and  an  immediate  exciting  one,  which  is  vascular.  The  explanation 
of  the  way  in  which  a  rise  in  the  general  blood  pressure  leads  to  an 
increase  of  the  intra-ocular  tension  is  based  on  the  assumption  that 
the  eyeball  is  a  closed  and  unyielding  capsule,  the  volume  of  the 
contents  of  which  is  a  fixed  quantity — an  assumption  which,  to  say 
the  least  of  it,  requires  proof. 

Amongst  other  local  causes  to  which  glaucoma  has  been  attri- 
buted are  abnormal  rigidity  of  the  sclerotic  and  obstruction  of  the 
venae  vorticosae  either  by  pathological  changes  in  their  walls  or  by 
compression  near  their  point  of  exit. 

It  is  very  probable  that  glaucoma  is  due  to  the  combination  of 
a  local  peculiarity  in  the  eye  itself,  with  some  general  constitutional 
derangement.     Sometimes  the  patients  are  neurotic  and  excitable^ 


CHAP.  TX.]  GLAUCOMA.  249 

or  there  may  be  arterio-sclerosis,  high  arterial  tension,  cardiac  dis- 
ease, or  renal  insufficiency. 

Treatment. — In  the  treatment  of  glaucoma,  with  rare  exceptions, 
an  operation  becomes  necessary.  The  performance  of  an  iridectomy 
is  the  means  discovered  by  von  Graefe,  in  the  year  1857,  for  the  cure 
of  glaucoma,  a  disease  which  had  hitherto  been  incurable. 

To  ensure  the  success  of  an  iridectomy  for  glaucoma,  so  far  as 
is  possible,  it  is  necessary  (1)  that  the  incision  should  be  peripheral — 
i.e.  as  far  back  in  the  corneo-sclerotic  margin  as  is  compatible  with 
the  introduction  of  the  knife  into  the  anterior  chamber,  and  with 
the  avoidance  of  injury  to  the  ciliary  body ;  (2)  that  the  portion 
of  iris  removed  should  be  wide — i.e.  involving  about  one-fifth  of  the 
circumference  of  the  iris  (Fig.  79) ;  and  (3)  that  it  should  be  abscised 
as  peripherally,  i.e.  as  close  to  the  root  of  the  iris,  as  possible. 

It  is,  moreover,  important  to  withdraw  the  knife  very  slowly 
from  the  anterior  chamber,  when  the  corneo-scleral  section  is  com- 
plete, in  order  that  the  aqueous  humour  may  flow  off  gradually,  lest 
an  intra-ocular  haemorrhage  from  the  sudden  reduction  of  tension 
should  occur. 

The  portion  of  iris  should  be  most  carefully  abscised,  so  that  no 
tag  of  it  may  remain  in  the  wound  and  become  caught  in  the  cicatrix 
in  the  course  of  healing.  Such  an  occurrence  is  apt  to  produce  a 
cystoid  cicatrix,  which  may  at  a  later  period  become  the  starting- 
point  of  irritation,  and  even  of  serious  inflammation.  Some  opera- 
tors prefer  von  Graefe's  cataract  knife  for  the  performance  of  the 
operation,  but  the  lance-shaped  keratome  is  the  instrument  usually 
employed. 

For  the  purpose  of  reducing  the  intra-ocular  tension,  it  matters 
nothing  what  region  of  the  iris  be  abscised ;  but,  as  a  rule,  the 
upper  quadrant  is  to  be  preferred,  for  there  the  resulting  coloboma, 
being  covered  to  a  great  extent  by  the  upper  lid,  will  give  rise  to  less 
diffusion  of  light  than  in  any  other  position. 

Immediately  after  the  operation,  palpation  of  the  eyeball  should 
show  a  marked  diminution  of  tension.  When  this  is  not  so  the 
prognosis  is  unfavourable.  Should  an  increase  of  tension  occur  on 
the  day  after  the  operation,  it  is  of  no  consequence,  as  it  passes  off 
again  in  the  course  of  the  next  few  days.  Until  then,  the  anterior 
chamber  will  not  be  restored,  and  we  see  cases  where  the  anterior 
chamber  does  not  appear  for  a  week  or  more.     The  bandage  should 


250  DISEASES   OF   THE  EYE.  [chap.  ix. 

be  worn  until  the  anterior  chamber  is  completely  restored.  It  is 
desirable  to  perform  the  operation  with  general  anaesthesia,  to  secure 
technical  accuracy.  The  pain  for  some  time  after  the  operation  is 
considerable,  and  should  be  relieved  by  a  hypodermic  injection  of 
morphia  in  the  corresponding  temple. 

Malignant  glaucoma  is  the  term  applied  to  certain  rare  cases, 
in  which  immediately  after  iridectomy,  although  the  operation 
may  have  been  faultlessly  performed,  the  lens  is  violently  pushed 
forwards,  blocking  the  wound,  obliterating  the  angle  of  the  anterior 
chamber,  and  preventing  any  fluid  fi'om  escaping  from  the  eye,  so 
that  it  is  soon  as  hard  as,  or  harder  than,  before  ;  and  the  condition 
is  accompanied  by  cloudiness  of  the  cornea,  injection  of  the  blood 
vessels,  chemosis,  violent  pain,  and  great  loss  of  sight.  This  com- 
plication seems  to  be  caused  by  the  retention  of  fluid  behind  the 
lens,  and  is  more  likely  to  occur  in  cases  of  chronic  simple  glaucoma, 
than  in  the  acute  forms  of  the  disease.  The  only  prospect  of  saving 
eyes  which  take  this  malignant  course  is  by  the  operation  of  posterior 
sclerotomy.  A  broad  needle,  or  a  Gr?efe's  knife,  is  entered  through 
the  sclerotic,  8  or  10  mm.  behind  the  outer  margin  of  the  cornea, 
and  the  blade  is  given  a  quarter  turn  on  its  axis,  so  as  to  make 
the  wound  gape,  or  the  latter  may  even  be  somewhat  enlarged  in  a 
meridianal  direction.  At  the  same  time  gentle  pressure  is  applied, 
by  means  of  the  upper  lid,  on  the  centre  of  the  cornea.  This  causes 
fluid  to  escape  through  the  scleral  wound  by  the  side  of  the  knife, 
and  it  also  causes  the  lens  to  go  back  into  its  place,  with  restoration 
of  the  anterior  chamber.  The  pressure  on  the  cornea  may  be  main- 
tained with  advantage  for  a  minute  or  somewhat  longer.  This 
operation  is  also  very  useful  as  a  preliminary  to  iridectomy  in  cases 
where  the  anterior  chamber  is  obliterated. 

The  therapeutic  value  of  a  correctly  performed  iridectomy  for 
glaucoma  depends  mainly  on  the  form  of  the  glaucoma — congestive, 
or  chronic  simple — for  which  the  operation  is  performed.  The  more 
congestive  or  acute  the  case,  the  more  favourable  is  the  prognosis 
in  respect  of  the  result  which  may  be  expected  from  the  operation ; 
and  hence  the  congestive  forms  are  more  favourable  for  operation 
than  the  simple  chronic  form. 

In  the  congestive  forms,  the  operation  may  be  expected  with 
great  certainty  to  preserve  permanently  whatever  vision  remains, 
and  it  can  restore  the  gi'eat  loss  of  sight  dependent  on  an  attack  of 


CHAP.  IX.]  GLAUCOMA.  251 

acute  congestive  glaucoma,  if  performed  without  delay.  It  will  not, 
in  these  acute  cases,  restore  vision  which  has  been  lost  for  a  few  days. 

But  in  chronic  simple  glaucoma,  when  the  disease  has  advanced 
so  far  that  the  contraction  of  the  field  has  approached  close  to  the 
fixation-point,  although  central  vision  may  still  be  fairly  good,  the 
prognosis  must  be  very  guarded.  Because  in  such  cases,  while  the 
iridectomy  may  prove  successful  in  so  far  as  reduction  of  tension  is 
concerned,  yet  the  contraction  of  the  field — i.e.  the  progress  of  the 
atrophy  of  the  optic  nerve — is  often  hastened.  Indeed,  where  the 
contraction  is  near  the  fixation-point  at  one  side  (Fig.  87),  and  is 
advanced  in  other  directions,  iridectomy  is  contra-indicated  in 
chronic  simple  glaucoma. 

Yet,  in  the  early  stages  of  chronic  simple  glaucoma,  while  central 
vision  is  as  yet  unaffected  ;  the  field  of  vision,  not  at  all,  or  only 
slightly  contracted ;  and  the  optic  disc  although  somewhat  cupped, 
yet  not  advanced  in  atrophy,  an  iridectomy  may  save  the  sight  per- 
manently. Even  at  a  later  stage,  with  some  contraction  of  the 
field  and  a  certain  amount  of  atrophy,  some  vision  is  often  saved, 
or  blindness  is  retarded. 

A  falling  away  in  vision  must  be  expected  in  almost  all  cases  of 
chronic  simple  glaucoma  after  the  iridectomy  ;  but  in  the  favourable 
cases  this  is  only  temporary,  and  the  sight  gradually  returns  to  its 
previous  state  in  the  course  of  some  weeks. 

In  cases  of  acute  or  subacute  glaucoma,  it  has  frequently  been 
observed  that  shortly,  even  within  a  few  hours,  after  the  perform- 
ance of  the  iridectomy,  the  other  eye,  previously  healthy,  or,  at  most, 
affected  with  but  slight  premonitory  symptoms,  is  attacked  with 
glaucoma.  It  is  probable  that  this  is  due  to  dilatation  of  the  pupil, 
with  pressing  of  the  iris  into  the  angle  of  the  anterior  chamber,  in 
consequence  of  confinement  in  the  dark  room  and  to  the  mental 
anxiety  attending  the  operation,  and  eserine  should  be  put  into 
the  sound  eye  as  a  precaution. 

The  Mode  of  Action  of  the  Operation,  it  is  believed,  consists 
not  so  much  in  the  removal  of  the  portion  of  iris,  as  in  the  nature 
of  the  sclero-corneal  wound,  which  in  successful  cases  results  in  the 
establishment  of  a  sclero-corneal  fistula  opening  into  the  anterior 
chamber  and  through  which  the  intra-ocular  fluids  flow  away. 
When  an  iridectomy  is  done,  the  small  portion  of  the  root  of  the 
iris  which  is  left,  becomes  folded  into  the  wound  and  tends  to 


252 


DISEASES   OF   THE   EYE. 


[chap,    IX. 


prevent  a  solid  closure.     This  view  is  supported  by  Priestley  Smith 
and  Treacher  Collins. 

In  those  cases  where  a  fistula,  as  described,  is  not  formed  by  the 
operation,  Collins  considers  that  the  obstruction  to  the  outflow  of 
lymph  becomes  freed,  either  by  the  iris  being  torn  away  at  its  thinnest 
part — that  is,  its  extreme  root — thus  leaving  a  large  portion  of  the 
filtration  angle  open  for  drainage  ;  or,  by  the  escape  of  the  aqueous 
and  the  drag  on  the  iris,  incidental  to  the  iridectomy  being  insufficient 
to  dislodge  the  periphery  of  an  iris,  which  has  only  recently  come 
into  apposition  with  the  cornea. 

Lagrange,  believing  in  the  necessity  of  providing  a  permanent 
drainage  of  the  anterior  chamber,  first  introduced  a  method  for 
establishing  a  subconjunctival  fistula,  without  any  inclusion  of  the 
iris.  The  essential  part  of  his  operation  consists  in  the  excision 
of  a  small  piece  of  sclerotic  at  the  sclero-corneal  margin  (sclerectomy). 
Various  other  procedures  have  lately  been  devised  for  the  accom- 
plishment of  the  same  object. 

These  operations  are  not  intended  so  much  for  the  congestive 
forms  of  glaucoma,  in  which  iridectomy  is  quite  satisfactory,  as  for 
the  chronic  forms. 

1.  Anterior  Sclerectomy  (Lagrange's  Operation). — At  least  half 
an  hour  before  the  operation  the  pupil  is  contracted  with  a  miotic. 
A  Gr£efe's  knife  is  entered  about  1  mm.  from  the  corneal  margin, 

and  the  counter  punc- 
ture is  made  at  a  cor- 
responding point  at  the 
opposite  side  ;  but  the 
incision  should  not  be 
so  long  as  that  for  a 
cataract  extraction. 
The  incision  is  then 
carried  upwards  into 
the  irido-corneal  angle  ; 
and,  when  it  is  about 
to  be  completed,  the  edge  of  the  knife  is  directed  somewhat  back- 
wards, so  as  to  bevel  the  centre  of  the  sclerotic  incision  in  cutting 
out,  and  finally  a  large  conjunctival  flap  is  formed  (Fig.  90).  The 
conjunctival  flap  is  then  lifted  with  a  forceps,  and  drawn  down- 
wards (Fig.  91)  ;  and,  with  suitably  curved  and  very  sharp  scissors, 


Fig.  90. 


r!HAP.    IX.] 


GLAUCOMA. 


253 


Fig.  91. 


a  sufiiciently  hirge  piece  of  the  sclerotic  is  resected  from  the  lower, 
or  corneal,  edge  of  the  wound,  and  the  conjunctival  flap  is  spread 
over  the  incision.  A 
punch  may  be  used 
instead  of  the  scis- 
sors for  the  resection 
of  the  sclerotic 
(Holth). 

This  operation  is  a 
simple  sclerectomy. 
I  f  necessary  the 
operation  of  sclero- 
iridectomy  is  done, 
and  then  the  iridec- 
tomy may  be  made 

in  the  ordinary  way ;  or  preferably,  only  a  peripheral  button-hole  is 
made  by  simple  incision  into  the  iris,  or  by  excision  of  a  small  piece 
near  the  base  of  the  iris.  The  button-hole  iridectomy  prevents 
prolapse  of  the  iris  quite  as  well  as,  or  even  better,  than  the  excision 
of  the  whole  piece  of  the  iris,  and  the  preservation  of  the  sphincter 
enables  miotics  to  act  with  better  effect,  if  it  be  required  to  use  them. 

In  the  cases  with  rather  high  tension,  sclerectomy  should  be 
combined  with  an  ordinary  iridectomy.  In  lower  degrees  of  tension, 
if  there  is  tendency  to  prolapse  of  the  iris  a  button-hole  iridectomy 
will  suffice,  and  it  should  also  be  resorted  to  in  cases  where  the  con- 
traction of  the  field  approaches  close  to  the  fixation  point.  Simple 
sclerectomy  should  be  reserved  for  chronic  simple  glaucoma  with 
intermittent  or  slight  increase  of  tension. 

2.  Sclerectomy  with  the  Trephine  {Elliot's  Operation  ^). — The  pupil 
having  been  contracted  by  eserine,  the  patient  is  told  to  look  down ; 
the  conjunctiva  is  then  seized  as  high  up  on  the  globe  as  possible,  and 
with  scissors  a  large  conjunctival  flap  is  made  concentric  with  the 
corneal  margin  and  ending  at  each  side  about  8  mm.  away  from  the 
limbus  (Fig.  92).     The  conjunctiva  is  next  dissected  down  to  the 


^  The  operation  of  trephining  for  glaucoma  was  done  independently 
in  the  same  year  by  Freeland  Fergus  and  Colonel  Elliot.  As  a  matter 
of  fact,  Fergus's  first  operation  preceded  Elliot's  in  point  of  time,  but  it 
is  to  the  latter  that  we  owe  the  details  of  the  operation  as  it  is  performed 
at  present. 


254 


DISEASES   OF   THE  EYE. 


[chap.    IX. 


limbus,  but  only  in  the  centre  (bh,  cc,  Fig,  92) ;  the  loosely  adherent 
conjunctiva  in  the  triangles  abc  help  to  keep   the   flap  in  position 

after  the  operation.  As  the  dis- 
section approaches  the  limbus,  the 
sclerotic  should  be  laid  bare.  With 
the  points  of  the  closed  scissors  the 
limbus  should  now  be  well  defined, 
as  a  rounded  ridge  slightly  over- 
riding the  sclerotic.  The  flap  is 
pushed  gently  down,  out  of  the 
way,  with  the  closed  forceps  so  as 
not  to  tear  it,  and  with  a  sharp, 
pointed  scissors  or  a  Bowman's 
needle  the  superficial  layers  of  the 
cornea  are  separated  until  a  dark 
crescent  1  or  2  mm.  broad  {cc, 
Fig.  92)  makes  its  appearance.  Any 
connective -tissue  tags  are  now 
cleared  away  from  the  sclerotic  and 
a  2  mm.  trephine  (Fig.  93)  is  ap- 
plied as  far  forwards  as  possible,  so  that  its  edge  w^ill  just  clear 
the  flap,  and  so  avoid  button-holing  it;  the  lower  end  of  the 
trephine,  if  necessary,  may  be  steadied  with  a  forceps  or  with  the 
guide  provided.  In  rotating  the  trephine  the  pressure  should 
be  a  little  greater  on  the  corneal  side,  as  it  is  thicker  than  the 
sclera  here.  After  a  few  turns  the  trephine  may  be  removed  to  see 
the  position  of  the  circular  groove  made  ;  it  can  easily  be  replaced 
again.     When  the  anterior  chamber  is  entered,  the  aqueous  wells 


Fig.  92.  abb  a,  line  of  con- 
junctival incision  ;  bb  cc,  area  of 
dissected  conjunctiva  ;  abc, 
triangles  of  conjunctiva  left 
attached ;  ccdd,  approximate 
area  in  which  sclerotic  is  laid 
bare.  The  crescent  of  cornea 
above  cc  is  the  portion  exposed 
by  "  splitting  "  when  the  flap  is 
reflected  down  ;  t,  trephine  hole. 


Fig.  93,     Elliot's  trephine,  with  "  chuck  "  for  grasping  the  blade. 


up  round  the  instrument,  there  is  a  slight  sucking  feeling,  the  pupil 
becomes  displaced  upwards,  and  the  patient  feels  a  momentary 
sensation  of  pain.  The  disc  usually  remains  attached  by  a  small 
hinge,  which  should  be  preferably  on  the  scleral  side,  and  in  most 
cases  the  iris  prolapses.     The  disc  of  sclera  is  now  grasped  with  the 


CHAP.    IX.] 


GLAUCOMA. 


255 


special  forceps  (Fig.  94)  and  both  it  and  the  prolapsed  iris  are  snipped 
off  together  with  a  sharp- pointed  iris  scissors,  with  the  result  that 
a  complete,  or  only  a  button-hole,  coloboma  is  made  (Fig.  96).  In 
carrying  out  this  part  of  the  operation,  the  still  adherent  disc  steadies 
the  eye  and  prevents  the  dragging  on  the  iris  which  would  result  if 


Fig.   94.     Elliot's  disc  forceps. 

the  iris  were  excised  separately.  If  the  pupil  is  not  central  or  iris 
tissue  is  engaged  in  the  trephine  hole  an  irrigator  is  used.  The  flap 
is  then  replaced,  no  suture  being  required  as  a  rule.  Atropine  is 
put  into  the  eye  on  the  third  day  or  even  earlier,  owing  to  the 
tendency  to  slight  iritis. 

Figs.  95  and  96  show  two  different  degrees  of  subconjunctival 
filtration  after  trephining.  This  operation  gives  on  the  whole  excellent 
results.  If  tension  recurs  it  may  be  due  to  the  following  causes  : — 
placing  the  trephine  hole  too  far  out ;  blocking  of  the  hole  by  uveal 


Fig.  95.  Trephine  operation 
with  slight  subconjunctival  oedema 
over  the  site  of  the  trephine  hole, 
which  appears  as  a  faint  dark  spot. 
Taken  one  year  after  operation. 


Fig.  96.  Trephine  operation 
with  more  marked  conjunctival 
swelling.  Peripheral  iridec- 
tomy. Taken  one  year  after 
operation. 


tissue,  or  by  the  proliferation  of  uveal  or  connective  tissue  ;  and 
plugging  of  the  hole  by  lens  or  vitreous.  Occasionally  the  disc 
removed  by  the  trephine  is  cut  clean  out  and  may  get   into  the 


256  DISEASES   OF   THE   EYE.  [chap.  ix. 

iiuterior  cliamber,  but  should  this  happen  it  can  be  washed  out  with 
an  irrigator,  or  can  be  removed  with  a  very  fine,  sharp  hook,  if 
necessary,  as  we  have  done  in  two  instances.  It  should  be  stated 
here  that  a  few  cases  of  late  infection  of  the  eye  have  been  recorded 
in  cases  operated  on  by  sclerectomy  or  trephining,  the  micro-organism 
probably  effecting  an  entrance  through  a  defect  in  the  conjunctival 
covering  of  the  wound. 

The  two  operations  just  described  are  those  which  have  met  with 
the  greatest  approval  as  substitutes  for  iridectomy.  Other  opera- 
tions having  the  same  purpose  are  : — 

3.   The  Small  Flap  or  Trapdoor  Operation   (Herbert). — Acting  on   the 
idea  that  trephining  and  sclerectomy  sometimes  produce  too  great  a  dim- 
inution of  the  tension,  Herbert  simply  makes  a  trapdoor 
ilZh—p      at  the  sclerocorneal  junction  (Fig.  97,  F). 
/^  \  The    transverse   incision   is   first   made    with   a    bent 

(        O       1  keratome  and   then    the  lateral  incisions  with  a  narrow 

V  y  cataract  knife  or  with  Harman's  twin  scissors.     The  fil- 

tration is  brought  about,  probably  by  defective  union  of 
Fig.   97.  the  flap,  owing  to  shrinkage  or  forward  displacement. 

4.  Iridencleisis  {Holth's  Operation). — This  consists  in 
subconjunctivally  drawing  one  of  the  pillars  of  the  iris,  after  iridectomy, 
into  the  wound  and  allowing  it  to  become  incarcerated  there,  so  as  to 
form  a  cystoid  cicatrix.  There  is  always  a  danger  of  late  infection  or 
even  of  sympathetic  ophthalmia  in  such  a  method  of  producing  filtration. 
5.  Cyclodialysis  {Heine's  Operation). — The  object  of  this  operation 
is  to  make  a  commmiication  between  the  supra-chorioidal  lymph  space 
and  the  anterior  chamber,  by  separating  the  ciliary  body  and  the  root 
of  the  iris  from  the  ligamentum  pectinatum,  whereby  freer  drainage  for 
the  intra-ocular  fluids  may  be  provided,  by  way  of  the  posterior  exits 
which  are  not  occluded. 

The  pupil  having  been  contracted  with  eserine,  the  operation  is  per- 
formed as  follows  : — About  5  mm.  from  the  corneal  margin  the  conjunctiva 
is  separated  from  the  sclerotic  ;  then,  with  a  straight  lance-shaped  knife, 
which  is  held  vertically  like  a  pencil,  an  incision  2  mm.  long  is  made, 
through  the  sclerotic,  as  deep  as  the  ciliary  muscle,  but  without  injury 
to  the  latter.  A  thin  spatula,  or  stiletto,  is  now  introduced  through  the 
opening  and  passed  forwards,  being  kept  close  to  the  inner  surface  of  the 
sclerotic,  until  it  reaches  the  ligamentum  pectinatum  through  which  it 
is  pushed  into  the  anterior  chamber.  By  lateral  motions  of  the  spatula 
the  dehiscence  can  be  extended  according  to  the  operator's  judgment, 
and  it  is  desirable  it  should  be  carried  to  about  one-third  of  the  circum- 
ference of  the  anterior  chamber.  If  the  spatula  be  slowly  withdrawn, 
no  aqueous  humour  is  lost,  and  in  that  case  a  reduction  of  tension  is  not 
observable  until  a  day  or  two  after  the  operation.  If  some  immediate 
reduction  of    tension  be  desired,  more  or  less  aqueous  is  caused  to  flow 


CHAP,  ix.j  GLAUCOMA.  257 


away.  The  operation  is  recommended  for  chronic  simple  glaucoma, 
htemorrhagic  glaucoma,  and  hydrophthalmos  (p.  2G0).  It  is  more  painful 
than  iridectomy. 

The  Non-Operative  Treatment  of  Glaucoma. — The  miotics  eserine 
and  pilocarpine  as  eye-drops  in  1  per  cent,  solutions  often  reduce 
glaucomatous  tension.  Their  action  depends  on  the  contraction 
of  the  pupil,  and  consequent  drawing  away  of  the  base  of  the  iris 
from  the  angle  of  the  anterior  chamber  ;  and,  if  the  miotic  does 
not  contract  the  pupil  well,  it  will  not  reduce  the  tension.  Cases 
of  acute  glaucoma,  brought  on  by  the  injudicious  use  of  atropine, 
may  frequently  be  completely  and  permanently  relieved  by  a  miotic 
instilled  a  few  times. 

In  acute  congestive  glaucoma  the  use  of  a  miotic  in  the  pre- 
monitory stage  will  often  postpone  the  true  glaucomatous  attack,  and 
even  sometimes  relieve  the  latter  for  the  time  ;  but  the  miotic 
treatment  cannot  produce  a  radical  cure,  and  it  should  only  be  used 
to  preserve  the  health  of  the  eye,  until  the  operation  is  performed. 

In  chronic  simple  glaucoma,  too,  miotics  bring  down  the  ten- 
sion when  they  contract  the  pupil,  and  may  be  used  in  those  cases 
where  the  patient  positively  declines  an  operation,  or  where  an 
operation  in  the  fellow  eye  has  not  resulted  satisfactorily,  or  where 
an  operation  is  contra-indicated  by  a  very  contracted  field.  The 
anti-giaucomatous  action  of  the  miotic  only  lasts  so  long  as  the 
pupil  is  contracted,  and  it  must  consequently  be  applied  once  or 
twice  in  twenty-four  hours.  The  miotic  treatment,  as  a  rule,  can 
only  be  regarded  as  palliative,  yet  cases  are  on  record  in  which 
such  treatment  has  succeeded  in  preserving  vision  for  a  great  many 
years.  Too  great  a  reliance  must  not  be  placed  on  them,  however, 
and  if  during  their  use  in  the  early  stages  of  the  disease  any  further 
contraction  of  the  field  should  take  place,  or  the  tension  should 
remain  high,  then  recourse  must  be  had  to  operation.  Along  with 
the  use  of  miotics,  errors  of  refraction  should  be  corrected,  especially 
hypermetropia,  and  the  eyes  should  not  be  overtaxed  in  the  matter 
of  reading  or  close  work. 

With  regard  to  constitutional  treatment,  glaucomatous  patients 
should  regulate  their  mode  of  living,  and  lead  a  quiet  life,  free  from 
mental  excitement.  They  should  also  avoid  excessive  bodily 
exertion.  Their  diet  should  be  simple,  and  moderation  should  be 
observed  in  the  use  of  alcohol  and  tobacco.  Sleeplessness,  if  present, 
17 


258  DISEASES   OF    THE   EYE.  [chap.  ix. 

must  be  combated.  The  administration  of  bromides  in  nem'otic 
patients,  and  of  potassium  iodide  in  cases  of  arterio-sclerosis,  may 
also  be  of  service.  In  acute  cases,  pending  or  preceding  operation, 
a  free  purge  should  be  given ;  and  for  the  relief  of  pain,  dionine  in 
powder  applied  to  the  eye,  morphia  given  hypodermically,  and  leeches 
applied  to  the  temple  are  very  useful  measures. 

It  may  be  here  once  more  stated  that,  while  miotics  possess  the 
power  of  reducing  glaucomatous  tension,  atropine,  and  all  my- 
driatics, bring  on  glaucoma  where  there  is  already  a  tendency  to  it. 
In  all  old  people,  therefore,  before  atropine  is  used,  it  is  well  to 
ascertain  that  the  tension  is  not  high. 

Treatment  of  Painful  Blind  Glaucomatous  Eyes. — Eyes  blind 
of  acute  glaucoma  may,  as  has  been  stated,  continue  to  be  pain- 
ful, and  to  render  the  patient's  life  very  miserable.  If  curative 
operations  fail,  excision,  or  evisceration,  must  be  resorted  to. 

Secondary  Glaucoma. 

In  addition  to  the  different  forms  of  primary  glaucoma  above 
described,  we  find,  as  already  stated,  that  high  tension  occurs  as  a 
sequel  of  diseased  conditions  previously  existing  in  the  eye.  There 
are  several  diseased  states  which  are  liable  to  become  complicated 
with  glaucomatous  tension  ;  but  it  should  be  clearly  understood 
that,  in  almost  every  instance,  the  immediate  cause  of  the  high 
tension  is  the  same  as  in  primary  glaucoma — namely,  a  closure  of 
the  angle  of  the  anterior  chamber. 

The  following  are  the  chief  conditions  which  are  liable  to  lead 
to  secondary  glaucoma  : — 

a.  Complete  Posterior,  or  Ring  Synechia  (p.  175).  The  iris, 
being  pushed  forwards  by  the  aqueous  humour  pent  up  in  the 
posterior  part  of  the  aqueous  chamber,  is  pressed  tightly  against 
the  cornea,  and  obliterates  the  angle  of  the  anterior  chamber  and  the 
ways  of  exit.  An  iridectomy  or  transfixion  of  the  iris  relieves  the 
high  tension  here. 

h.  Perforating  Wounds  or  Ulcers  of  the  Cornea,  followed  by 
incarceration  of  the  iris  in  the  resulting  cicatrix.  The  iris,  being 
drawn  tautly  towards  the  cornea,  a  large  portion,  or  the  whole,  of 
the  filtration  angle  may  be  closed  by  it.     An  iridectomy  is  indicated. 

c.  Dislocation  of  the  Crystalline  Lens  into  the  Anterior  Chamber. 


CHAP.  IX.]  GLAUCOMA.  259 


Here  the  iioriiicil  How  of  the  iutra-ocular  fluids  through  the  pupil, 
towards  the  filtration  angle,  is  arrested  by  reason  of  the  presence  of 
the  lens  in  the  anterior  chamber.  The  onward  current  then  presses 
the  iris  against  the  posterior  surface  of  the  lens,  and  the  root  of  the 
iris,  whicli  is  unsupported  by  the  lens,  against  the  periphery  of  the 
cornea,  and  in  this  way  the  angle  of  the  anterior  chamber  is  closed. 
In  these  cases  the  lens  must  be  removed  from  the  eye. 

d.  Lateral  (traumatic)  Displacement  of  the  Crystalline  Lens. 
The  lens,  being  pushed  in  between  the  ciliary  processes  and  the 
vitreous  humour,  drives  the  root  of  the  iris  forwards  against  the 
cornea  at  that  place,  while  in  other  parts  of  the  circumference 
the  displaced  vitreous  acts  in  the  same  way.  In  these  cases,  too,  the 
lens  must  be  removed. 

e.  Traumatic  Cataract.  The  swelling  lens  pushes  the  iris  forwards 
against  the  angle  of  the  anterior  chamber.  Evacuation  of  the  lens 
should  be  performed. 

/.  After  Cataract  Extraction.  For  explanation  of  this  see 
p.  286. 

g.  Intra-ocular  Tumours  (p.  219).  The  growth  of  the  tumour 
gives  rise  to  a  transudation  of  serum  from  the  chorioid  which 
detaches  the  retina,  and  after  a  time  pushes  the  lens,  the  ciliary 
processes,  and  the  iris  forwards,  and  thus  closes  the  filtration  angle. 
In  other  cases  the  ligamentum  pectinatum  and  canal  of  Schlemm 
may  be  blocked  by  tumour  cells  (Plate  IV.  Fig.  5). 

h.  Serous-Cyclitis,  or  Iritis.  Here  the  filtration  angle  is  not 
closed.  But  the  filtration-power  of  the  eye  is  diminished,  perhaps 
by  tissue  changes  around  the  filtration  angle,  as  well  as  by  the 
albuminous  exudation  in  the  anterior  chamber. 

Another,  and  peculiar,  form  of  secondary  glaucoma  is  Hsemor- 
rhagic  Glaucoma.  Retinal  haemorrhages,  usually  due  to  thrombosis 
of  the  central  vein,  are  sometimes  followed,  a  few  weeks  later,  by 
increased  intra-ocular  tension,  which  generally  assumes  the  symptoms 
of  acute  or  subacute  glaucoma,  and,  more  rarely,  those  of  chronic 
simple  glaucoma.  A  satisfactory  explanation  for  these  cases  has 
not  been  offered.  When  such  a  glaucoma  becomes  pronounced, 
it  is  not  usually  possible  to  distinguish  it  from  a  primary  form  of 
the  disease.  This  disease  is  practically  hopeless.  Iridectomy  is 
more  likely  to  do  harm  than  good,  the  operation  being  almost  in- 
variably followed  by  fresh  intra-ocular  haemorrhages,  and  by  a  further 


260 


DISEASES   OF   THE   EYE. 


[chap.   IX. 


increase  of  tension.     Sclerotomy  is  said  by  some  to  be  followed  by 
fairly  good  results  ;    but  the  miotic  treatment  is  ineffectual. 


Congenital  Hydrophthalmos. 

This  disease,  also  known  as  Buphthalmos,  and  as  Cornea  Globosa, 
is  glaucoma  of  early  childhood,  tlie  incipient  stages  of  which  are 
intra-uterine.  The  eyeball  is  enormously 
enlarged  (Fig.  98),  the  cornea  very  much 
wider  than  normal  in  its  diameter,  the 
anterior  chamber  deep,  the  iris  trembling, 
and  the  sclerotic  thinned.  Increase  of 
tension  and  cupping  of  the  optic  papilla 
are  usually  present,  and  there  is  severe 
pain  if  the  tension  become  high.  This 
disease  is  sometimes  seen  in  association 
with  neurofibromatosis. 

The  Pathology  of  the  disease  is  obscure. 
Treacher  Collins  holds  that  it  is  caused  by 
a  failure  in  the  separation  of  the  iris  from 
the  back  of  the  cornea  at  its  extreme 
periphery,  in  course  of  the  development  of 
the  eye  ;  E.  von  Hippel  believes  it  to  be 
the  result  of  an  intra-uterine  inflamma- 
tion ;  while  Seef elder's  investigations  lead 
him  to  regard  it  as  due  to  mal-development  of  the  ways  of  exit  of 
the  intra-ocular  fluids.  In  many  cases  there  is  more  or  less  complete 
absence  of  Schlemm's  canal. 

Treatment. — This  disease  is  not  very  amenable  to  treatment. 
A  few  cases  of  spontaneous  recovery  have  been  recorded.  Iridectomy 
sometimes  arrests  the  disease,  but  often  does  harm.  A  few  good 
results  have  been  obtained  with  the  ''  trapdoor "  operation  and 
with  the  trephine.  When  the  disease  is  very  advanced,  treatment 
is  of  no  avail  except  for  the  relief  of  pain. 


Fig.  98.  Congenital 
Buphthalmos  in  the  right 
eye.  The  cornea  of  the 
left  eye  was  larger  than 
normal. 


CHAPTER    X. 

DISEASES   OF   THE   CRYSTALLINE  LENS. 

The  crystalline  lens,  being  an  epithelial  structure  like  the  hair  or 
nails,  is  not  subject  to  inflammation,  the  changes  which  take  place 
in  it  being  degenerative  in  character.  It  is  enclosed  in  a  capsule 
which  is  continuous  round  its  margin,  although  for  convenience  of 
reference  we  speak  of  the  anterior  and  the  posterior  capsule.  The 
inner  or  lental  surface  of  the  anterior  capsule  is  alone  lined  with 
epithelium,  which  under  certain  conditions  may  proliferate.  The 
lens  is  bathed  by  the  aqueous  humour  from  which  it  derives  its 
nutrition  by  osmosis,  through  the  capsule,  and  the  integrity  of  the 
latter  is  essential  to  the  preservation  of  the  transparency  of  the  lens. 

The  only  structures  in  contact  with  the  lens  are  the  vitreous 
h  umour  behind  and  the  pupillary  portion  of  the  iris  in  front.  It  is 
suspended  by  the  zonule  inside  the  ring  formed  by  the  ciliary  pro- 
cesses, but  is  separated  from  them  by  an  interval,  the  '  circum- 
lental  space.'  The  margin  of  the  normal-sized  lens  is  never  visible, 
even  with  a  dilated  pupil.  Degeneration  of  the  lens  gives  rise  to 
the  opacity  called  cataract,  and  proliferation  of  the  capsular  epi- 
thelium causes  capsular  cataract. 

Apart  from  cataract  the  only  abnormalities  of  the  lens  which 
require  consideration  are  dislocation  and  malformations.  Cataract 
may  be  complete — occupying,  in  its  final  stage,  the  w^hole,  or  nearly 
the  whole,  of  the  lens  ;  or  partial — occupying  only  part  of  the  lens, 
and  with  little  or  no  tendency  to  extend  to  other  parts  of  it. 

Complete  Cataracts. 

Of  these,  the  most  common  is  Senile  Cataract.  It  occurs  in 
persons  of  over  fifty  years  of  age,  rarely  in  those  under  forty-five 
years  of  age. 

Progress,    Pathogenesis,    and    Etiology    of    Senile    Cataract. — In 

261 


262  DISEASES   OF   THE  EYE.  [chap.  x. 

incipient  senile  cataract,  the  opacity  is  found  : — a.  In  the  cortical 
layers  of  the  lens,  especially  at  its  equator,  and  in  the  latter  position 
can  often  be  detected  only  with  transmitted  light  from  the  ophthal- 
moscope mirror,  or  with  focal  illumination,  even  if  the  pupil  be 
dilated  with  atropine.  This  opacity  takes  the  form  of  trian- 
^^ular  sectors,  of  which  the  bases  are  towards  the  equator  of  the 
lens,  while  the  apices  are  towards  its  centre.  These  lines  or  sectors 
look  bhxck  with  transmitted  light,  but  grey  with  focal  illumination, 
and  between  them  clear  lens-substance  is  present.  These  opacities 
begin  most  frequently  in  the  lower  inner  quadrant  of  the  lens.  Or, 
h.  Incipient  cataract  may  appear  as  a  diffuse  opacity  in  the  layers 
surrounding  the  nucleus  of  the  lens.  Or,  c.  The  opacity  may  com- 
mence both  near  the  equator  and  around  the  nucleus  at  about  the 
same  time.  Or,  d.  The  opacity  may  in  the  beginning  be  dissem- 
inated through  the  cortex,  in  the  form  of  flocculi,  dots,  and  lines. 
e.  In  some  cataracts,  in  a  very  incipient  stage,  there  are  no  absolute 
opacities  ;  but  with  weak  transmitted  light — i.e.  from  a  plane  oph- 
thalmoscope mirror — numbers  of  fine  dark  lines  will  be  seen  in  the 
lens,  which  vanish  and  reappear  according  as  the  incidence  of  the 
light  is  altered  ;  while  not  until  later  do  true  opacities  make  their 
appearance.  Gradually  the  cataract  extends  to  other  parts  of  the 
lens,  until  the  whole  cortical  portion  is  opaque. 

In  senile  cataract,  the  very  nucleus  itself  does  not  become  cata- 
ractous,- although  it  is  usually  sclerosed  (harder  and  drier). 

Sclerosis  of  the  nucleus  of  the  lens  is  a  physiological  condition  of 
advanced  life,  and  will  be  found  in  many  an  eye  where  there  is  no 
cataract.  It  gives  to  the  senile  non-cataractous  lens,  as  seen  with 
a  dilated  pupil  or  with  focal  illumination,  a  peculiar  smoky  appear- 
ance, which  is  often  mistaken  by  inexperienced  persons  for  cataract ; 
but  examination  with  transmitted  light  will  show  that  there  is  no 
true  opacity.  When  a  senile  cataract  has  become  complete,  the 
sclerosed  nucleus  imparts  to  its  centre  a  brownish  or  yellowish  hue, 
while  the  other  parts  of  the  lens  are  of  a  greyish  white.  As  a  rule, 
the  most  peripheral  layers  of  the  cortex  are  the  last  to  become 
opaque.  Accordingly  as  the  lens/l)ecomes  opaque,  it  often  swells 
slightly  ;  and  when  this  occurs  the  anterior  chamber  becomes  a 
little  shallower. 

Until  the  whole  cortex  is  opaque,  a  clear  interval  will  be  present 
between  the  iris  and  the  cataractous  part ;   and,  on  examination 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  2G3 


with  the  oblique  light,  a  shadow  of  the  iris  will  be  thrown  on  the 
cataractous  part  at  the  side  from  which  the  light  comes  ;  and  the 
cataract,  in  this  way,  is  proved  to  be  immature  in  the  strict  sense. 
If  the  whole  cortical  substance  be  opaque,  the  thickness  of  the 
capsule  alone  will  intervene  between  the  pupillary  margin  and  the 
opacity,  and  no  shadow  of  the  iris  can  be  thrown  on  the  latter. 

In  addition  to  this  examination  with  focal  light,  the  pupil  should 
be  dilated,  and  the  lens  examined  by  transmitted  light  from  the 
ophthalmoscope  mirror,  when  a  completely  opaque  cataract  should 
permit  of  no  red  reflection  being  obtained,  in  any  direction,  from 
the  fundus  oculi. 

As  soon  as  the  whole  of  the  cortical  substance  has  become 
opaque,  any  swelling  of  the  lens  which  there  may  be  subsides,  and 
the  anterior  chamber  finally  regains  its  normal  depth.  If  there  be 
no  glittering  sectors  in  the  cortex,  the  cataract  is  now  mature,  or 
'  ripe  '  for  operation — that  is  to  say,  if  an  extraction  operation  be 
now  undertaken,  the  lens  will  be  with  great  certainty  delivered  in 
its  entirety  ;  whereas,  prior  to  this  stage,  cortical  substance  would 
have  been  more  liable  to  adhere  to  the  capsule,  and  to  be  left  behind. 

But  a  cataract  is  immature,  notwithstanding  the  absence  of  iris- 
shadow  and  of  the  illuminable  pupil,  and  even  though  the  anterior 
chamber  be  of  normal  depth,  if  the  cortex  present  well-marked 
glittering  sectors.  The  glitter  of  the  different  sectors  varies  with 
the  angle  of  illumination,  so  that  the  surface  appears  facetted.  In 
such  a  lens  there  are  thin  transparent  flakes,  as  well  as  opaque  flakes, 
close  beneath  the  capsule  ;  and,  if  an  extraction  operation  be  under- 
taken, the  transparent  portions  are  very  apt  to  remain  within  the  eye, 
in  spite  of  every  attempt  to  remove  them.  A  few  months  later 
the  sectors  lose  their  sharp  contour,  break  down,  and  finally  dis- 
appear.    We  can  then  depend  upon  the  exit  of  the  whole  cataract. 

Yet  in  persons  over  sixty  years  of  age,  in  whom  the  nucleus  is 
usually  large,  many  a  cataract  can  be  completely  removed  which 
does  not  come  up  to  the  strict  standard  of  maturity  just  laid  down  ; 
and,  at  that  time  of  life,  the  surgeon  need  not  hesitate  to  operate, 
without  waiting  for  absolute  B^iaturity  if  the  patient  be  materially 
incommoded  for  want  of  sight!  Strict  asepsis,  and  the  use  of  the 
irrigator  for  the  removal  of  cortical  remains,  have  rendered  the 
removal  of  immature  cataracts  quite  a  safe  procedure. 

The  foregoing  is  the  most  common  course  of  events  in  the  progress 


264  DISEASES   OF    THE   EYE.  [chap.  x. 

of  a  senile  cataract ;  but  there  is  a  less  common  form  of  it,  in  which 
total  opacity  of  the  cortical  layers  never  does  come  about.  In  this 
form  the  lens  is  occupied  by  radiating  linear  opacities  up  to  the  very 
capsule  ;  while  between  these  opaque  lines  there  are  clear  intervals, 
which  may  even  admit  of  the  fundus  oculi  being  examined,  although 
dimly,  and  which  allow  of  a  certain  amount  of  sight.  These  cataracts 
usually  occur  in  myopic  eyes,  and  they  can  be  successfully  removed. 

After  the  stage  of  maturity  a  cataract  gradually  goes  on  to  be 
h/pennature.  Here  one  of  two  changes  takes  place  ;  either  the 
cortical  substance  breaks  down,,  and  becomes  fluid,  the  nucleus 
retaining  its  consistency,  and  gravitating  to  the  lowest  part  of  the 
capsule  (Morgagnian  cataract)  ;  or,  more  commonly,  the  cortical 
substance  dries  up,  as  it  were,  and  finally  comes  to  form,  with  the 
nucleus,  a  hard  flat  disc.  Accompanying  these  changes  in  the  lens- 
substance  are  changes  in  the  epithelium  lining  the  inner  surface  of 
the  anterior  capsule,  which  result  in  a  thickening  of  the  capsule. 
In  a  Morgagnian  cataract  the  fluid  cortex  finally  undergoes  absorp- 
tion, and  the  anterior  and  posterior  capsules  come  in  contact  (cata- 
racta  membranacea).  In  some  cases  the  capsule  remains  more  or 
less  transparent,  and  the  sight  may  greatly  improve  ;  and  cases  are 
on  record  of  spontaneous  cure  of  cataract,  due  to  intracapsular 
absorption. 

The  dimensions  of  the  nucleus  vary  a  good  deal.  In  some 
cataracts  it  is  small,  and  these  are  called  soft  cataracts,  as  they 
consist  chiefly  of  the  soft  cortical  substance.  In  others — and  as  a 
rule  in  patients  over  sixty  years  of  age^the  nucleus  is  large,  and 
these  are  called  hard  cataracts,  although  they  are  not  hard  through- 
out. The  size  of  the  nucleus  can  be  estimated  pretty  accurately 
by  the  extent  and  intensity  of  the  yellowish  or  brownish  reflection, 
which  is  obtainable  by  focal  illumination  from  the  centre  of  the 
cataract. 

In  some  senile  cataracts,  the  sclerosis  is  not  confined  to  the 
nucleus,  but  extends  to  the  cortical  layers  as  well.  This  causes 
much  disturbance  of  sight,  and  the  term  cataracta  nigra  is  given 
to  these  lenses,  from  their  very  dark  hue,  although  they  are  not 
cataracts  in  the  true  sense  of  the  term.  They  require  operation,  and, 
as  they  are  always  of  large  size,  wide  openings  have  to  be  made  to 
deliver  them. 

In  the  lenses  of  young  people  there  is  no  nucleus  :  consequently, 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  265 


in  the  complete  cataracts  of  children  and  of  young  adults,  there  is 
no  nucleus  ;  the  whole  lens  becomes  opaque,  and  the  cataract  is 
always  soft. 

Pathogenesis  of  Senile  Cataract. — According  to  Priestley  Smith's  investi- 
gations a  diminished  rate  of  growth  of  the  lens  precedes  the  formation  of 
cataract  ;  and  it  is  held  by  some  that  the  cataractous  process  in  the 
senile  lens  is  the  result,  in  the  first  instance,  of  a  rapid  sclerosis  and  shrink- 
ing of  the  nucleus.  If  the  process  of  sclerosis  and  shrinking  be  very 
gradual,  cataract  does  not  appear,  because  the  cortical  layers  of  the  lens 
have  time  to  accommodate  themselves  to  the  altered  state  of  things  ; 
but,  if  the  shrinkage  be  rapid,  the  cortical  layers  cannot  so  rapidly  accom- 
modate themselves,  and  consequently  the  fibrillse  of  these  layers  bscome 
separated  somewhat  froin  each  other,  fluid  collects  in  the  interspaces,  and 
causes  disintegration  of  the  lens-substance,  gradually  leading  to  opacity 
of  the  whole  lens.  As  the  opacity  increases,  more  fluid  is  present  in  the 
lens,  and  this  causes  swelling  of  the  lens.  When  the  whole  cortex  has 
become  opaque,  the  fluid  contents  begin  to  diminish,  and  the  lens  returns 
to  its  normal  size.  Senile  cataract,  according  to  this  view,  is  entirely 
a  local  process.  But  it  has  not  been  proved  that  the  nucleus  of  these 
cataractous  lenses  does  undergo  a  process  of  shrinkage. 

Others  incline  to  the  view,  for  which  they  advance  fairly  well-founded 
reasons,  that  senile  cataract  is  the  result  of  certain  specific  toxines  which 
enter  the  lens  and  damage  the  epithelial  cells  lining  its  capsule,  and  that 
this  leads  on  to  derangement  of  all  the  lenticular  fibres. 

Burdon  Cooper  believes  that  cataract  is  the  result  of  a  hydrolysis  of 
the  lens  protein,  which  results  in  the  formation  of  tyrosin.  Tyrosin  is 
not  present  in  the  normal  lens  but  is  found  in  the  aqueous  and  in  the 
lens  in  senile  cataract,  and  also  in  the  aqueous  humour  after  discission  of 
the  clear  lens. 

Both  the  congenital  and  acquired  forms  of  cataract  are  often  here- 
ditary. 

Senile  cataract  has  not  been  associated  with  any  recognisable 
disturbance  of  the  general  health,  but  there  is  some  evidence  to  con- 
nect it  with  a  renal  impermeability  not  sufficient  to  manifest  itself 
in  appreciable  clinical  symptoms. 

The  Symptoms  to  which  senile  cataract,  in  the  earliest  stages, 
gives  rise  are  :  more  or  less  dimness  of  vision,  as  if  looking  through 
a  mist,  or  a  net,  and  sometimes  polyopia.  The  polyopia  annoys 
the  patients  especially  in  the  evening,  when  they  look  at  gas  or 
candle  flames,  the  moon,  etc.  It  is  caused  by  the  irregular  astig- 
matism produced  by  the  slight  changes  which  sometimes  precede 
actual  opacities  (p.  262),  or  by  the  points  of  early  peripheral  opa- 
cities extending  into  the  pupillary  area. 


266  DISEASES   OF    THE   EYE.  [chap.  x. 


In  some  cases  of  incipient  cataract  there  is  an  increase  in  the 
refracting  power  of  the  lens,  with  the  result  that  the  patient  becomes 
slightly  myopic,  if,  previously,  he  have  been  emmetropic. 

Oradually,  as  the  opacity  extends  to  other  parts  of  the  lens,  the 
acuteness  of  vision  becomes  decidedly  affected  ;  and  this  is  the 
more  marked,  the  more  the  cortex  at  the  anterior  and  posterior  poles 
of  the  lens  is  involved.  In  those  cases  where  the  equatorial  parts 
of  the  lens  are  but  little  affected,  while  the  polar  regions  are  a  good 
deal  affected,  the  patients  see  better  in  the  dusk,  or  with  their  backs 
to  the  light,  than  when  their  eyes  are  exposed  to  a  strong  light ;  the 
reason  being  that  in  the  dusk  the  pupil  is  dilated,  and  light  can  pass 
through  the  clearer  periphery  of  the  lens,  while  in  a  strong  light  the 
pupil  is  contracted.  On  the  other  hand,  when  the  opacity  is  con- 
fined rather  to  the  equator  of  the  lens,  a  strong  light  is  not  disturbing 
to  sight ;  or,  if  the  centre  of  the  lens  be  quite  clear,  a  strong  light 
may  even  be  agreeable  to  the  patient. 

According  as  the  lens  becomes  more  opaque,  the  acuteness  of 
vision  is  proportionately  reduced,  until,  finally,  even  large  objects 
cannot  be  discerned,  and  only  quantitative  perception  of  light  re- 
mains. Some  cataracts,  however,  when  quite  ripe,  still  admit  of 
finger-counting  at  a  few  feet. 

In  advanced  stages  of  the  disease,  when  the  opacities  oct-upy 
a  great  portion  of,  or  the  entire  cortex,  they  are  easily  recognised 
even  by  ordinary  daylight,  often  giving  a  greyish  appearance  to 
the  pupil. 

luflaminatory  exudation  of  some  standing  in  the  area  of  the  pupil 
would  afford  a  somewhat  similar  appearance,  but  would  be  attended  by 
other  signs  of  the  previous  inflammatory  process,  such  as  synechise,  dis- 
organisation of  the  iris,  etc.,  and  the  opacity  would  be  seen  to  lie  more  in 
the  plane  of  the  iris  than  does  any  lental  opacity. 

The  length  of  time  occupied  by  the  ripening  of  a  cataract  varies 
in  different  cases  from  a  few  months  to  many  years.  In  very  old 
persons  the  progress  is,  in  general,  more  rapid  than  at  an  earlier 
time  of  life.  That  form  which  commences  at  the  equator  as  fine 
lines  is  slower  than  that  with  flocculent  opacities,  or  than  that  in 
wdiich  the  cortex  around  the  nucleus  is  likewise  implicated  at  an 
early  period. 

All  examinations  as  to  the  conditions  of  the  lens  are  rendered 
easier  and  more  conclusive  if  the  pupil  be  previously  dilated  ;    but 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  2G7 

the  tension  of  the  eye  should  be  ascertained  before  a  mydriatic  is 
instilled,  lest  glaucoma,  or  a  tendency  to  it,  be  present. 

Treatment. — It  is  very  doubtful  whether  purely  medical  treat- 
ment is  of  any  avail  in  the  treatment  of  cataract  at  any  stage.  The 
only  treatment  of  this  kind  which  seems  to  have  produced  slight 
improvement  in  some  cases  is  potassium  iodide,  administered  in- 
ternally, or  applied  locally  by  eye  baths  (2  to  6  per  cent,  solutions) 
or  subconjunctival  injections  of  1  or  2  per  cent,  solutions.  Removal 
of  the  cataract  by  operation  is  the  only  real  cure  for  blindness 
caused  by  it. 

In  cases  of  incipient  cataract,  or  in  those,  rather,  which  have 
advanced  somewhat  beyond  this  stage,  we  often  find  that  vision 
is  improved,  or  made  more  pleasant,  by  the  wearing  of  tinted  glasses 
to  moderate  the  light.  With  commencing  cataract,  where  slight 
myopia  has  come  on,  low  concave  glasses  for  distant  vision  will,  for 
a  time,  be  found  of  service  ;  while,  for  reading,  stenopseic  glasses 
sometimes  give  good  results.  Yet,  as  a  rule,  patients  are  unwilling 
to  avail  themselves  of  any  of  these  aids. 

Dilatation  of  the  pupil  is  in  many  cases  of  great  benefit,  especially 
where  the  nucleus  is  much  more  opaque  than  the  cortical  portion  ; 
but  sometimes  the  resulting  diffusion  of  light  is  distressing  to  the 
patient,  and  greater  impairment  and  confusion  of  vision  are  pro- 
duced. 

Patients  with  incipient  or  advancing  cataract  may,  with  impunity, 
be  allowed  to  make  every  use  they  can  of  the  sight  they  possess  ; 
and  the  surgeon  should  give  them  hints  as  to  the  arrangement  of 
light  in  their  rooms,  and  for  their  work,  etc.,  so  as  to  enable  them  to 
employ  their  sight  to  the  best  advantage. 

The  truly  distressing  period  in  the  progress  of  cataract,  when 
both  eyes  are  affected,  lies  between  the  advent  of  that  degree  of 
blindness  which  incapacitates  the  patient  for  reading  or  writing,  or 
for  making  his  way  about  alone,  and  the  occurrence  of  maturity, 
or  of  that  degree  of  maturity  which  is  deemed  requisite  for  successful 
removal.  This  is  often  a  lengthened  time.  Fortunately,  in  many 
instances  the  cataract  in  one  eye  is  much  more  advanced  than  that 
in  the  other  ;    and  then  no  such  trial  need  be  passed  through. 

The  question  is  often  asked  by  patients,  whether  the  cataract  in  one 
eye  should  be  extracted  until  both  eyes  are  blind.  The  answer  is  : — 
A  patient  with  one  mature  cataract,  and  the  other  progressing  towards 


268  DISEASES   OF   THE   EYE.  [chap.  x. 

maturity,  should  have  the  ripe  cataract  removed.  Hypermaturity  is  thus 
avoided,  and  also  the  stage  of  blindness  above  referred  to.  Again,  if  there 
be  a  ripe  cataract  in  one  eye,  and  not  even  incipient  cataract  in  the  ether, 
it  is  often  advisable  to  operate  for  the  purpose  of  increasing  the  binocular 
field  of  vision. 

Artificial  Ripening. — For  the  purpose  of  hastening  the  maturity  of 
a  cataract,  when  the  patient  has  become  incapacitated,  the  following 
method  is  sometimes  used.  The  anterior  chamber  is  paracentesed,  and, 
when  the  aqueous  humour  has  flowed  of?,  the  lens  is  massaged  with  gentle 
circular  motions,  with  the  angle  of  a  strabismus  hook,  or  other  suitable 
instrument,  applied  to  the  anterior  surface  of  the  cornea.  The  circular 
massage  must  be  applied,  through  the  cornea,  to  the  entire  surface  of 
the  lens  as  far  as  its  very  periphery.  Within  forty -eight  hours  the  cortex 
becomes  opacjue.  The  proceeding  acts  by  deranging  the  epithelium  of  the 
anterior  capsule,  after  which  the  aqueous  humour  can  pass  through  the 
intact  capsule,  and  produce  disorganisation  of  the  lens  fibres,  as  occurs 
after  the  operation  of  discission.  Care  must  be  taken  that  the  pressure 
be  not  too  great,  or  the  capsule  may  be  ruptured,  or  severe  iritis  may  be 
caused.  This  measure  is  employed  less  frequently,  since  it  has  become 
the  practice  to  extract  cataract  in  many  cases  before  maturity  is  reached. 

Complete  Congenital  Cataract. — Children  are  sometimes  born 
with  ciystalline  lenses  opaque  in  all  their  layers,  w^hile  the  other 
tissues  of  the  eye  are  healthy.  With  congenital  cataract  defects 
of  the  chorioid  or  retina,  or  congenital  amblyopia  without  ophthal- 
moscopic appearances,  are  also  sometimes  present,  and  are  usually 
indicated  by  nystagmus.  These  cataracts  sometimes  shrink,  and 
the  remaining  lens  substance  is  contained  in  a  flattened  and  much- 
thickened  capsule  which  is  sometimes  difficult  to  divide.  Children 
with  congenital  cataracts  are  sometimes  imbecile  or  weak-minded. 

TrcatiHcnt. — Discission. 

Complete  Cataract  of  Young  People.— The  spontaneous  occur- 
rence of  total  acquired  cataract  in  the  youthful  lens  is  of  rare  occur- 
rence, and  its  pathogenesis  is  unknown. 

Treatment. — Discission. 

Diabetic  Cataract. — This  is  a  complete  opacity  of  the  crystalline 
lens  occurring  in  diabetes,  but  the  immediate  cause  of  the  cataract 
is  not  known.  The  cataract  does  not  differ  in  appearance  or  con- 
sistency from  other  cataracts,  according  to  tlie  time  of  life  of  the 
patient. 

Treatment  and  Prognosis  of  Diabetic  Cataract. — A  few  cases  have 
been  recorded  in  which  upon  reduction  of  the  sugar  in  the  urine,  by 
suitable  anti-diabetic  treatment,  the  central  opacity  disappeared ; 


CHAP.  X.]  THE    CRYSTALLINE   LENS.  209 


but,  as  a  rule,  extraction  of  the  cataract  is  the  method  which  must 
be  relied  on  to  restore  sight,  and,  contrary  to  a  very  general  opinion, 
these  cases  are  not  very  unfavourable  for  extraction  operations, 
except  when  the  diabetes  is  rapidly  progressive  or  there  is  acetonuria. 
We  have  operated  on  cases  of  this  kind,  and  always  with  success, 
save  once,  when  the  eye  was  lost  by  intra-ocular  haemorrhage  ;  and 
we  have  seen  such  cases  operated  on  successfully  by  others.  Occa- 
sionally patients  operated  on  for  diabetic  cataract  die  of  coma 
within  a  fortnight  or  so  after  the  operation,  and  hence,  when  opera- 
tion is  contemplated,  it  is  necessary  to  submit  the  possibility  of 
this  occurrence  to  the  patient. 

Glass-Blower's  Cataract. — Glass-blowers  are  very  liable  to  cataract. 
The  appearance  of  the  cataract  is  characteristic  ;  it  consists  of  a  well- 
defined  disc  of  opacity  in  the  centre  of  the  posterior  cortex  of  the  lens. 
It  only  occurs  in  men  who  have  been  engaged  at  the  work  for  many  years. 
Whether  this  is  due  to  the  great  lieat  to  which  their  eyes  are  exposed 
to  the  ultra-violet  rays,  to  profuse  sweating,  or  to  the  congestion  in  the 
blood-supply  of  the  uvea  caused  by  the  repeated  act  of  blowing,  or  to 
some  other  cause,  is  unknown. 

Treatment. — Extraction. 

Black  Cataract. — This  name,  as  above  stated,  is  sometimes  given  to 
cases  of  extreme  sclerosis  of  the  lens,  in  which  it  assumes  a  dark  brown 
colour  ;  but  in  other  cases  the  lens  is  really  black.  The  pigment  is  not 
a  direct  derivative  of  haemoglobin,  but  is  the  result  of  a  cellular  activity 
like  melanin.  The  prognosis  for  an  operation  in  these  latter  cases  is  not 
good,  as  they  are  often  complicated  with  disease  of  the  chorioid,  or  \\ith 
haemorrhage  in  the  vitreous  humour. 

Partial  Cataracts. 

These  are  nearly  all  congenital. 

Central  Cataract. — This  is  a  congenital  and  usually  non-pro- 
gressive form.  It  is  an  opacity  of  the  central,  or  oldest,  lens-fibres, 
while  the  peripheral  layers  remain  clear. 

Treatment. — Discission,  or  iridectomy. 

Zonular,  or  Lamellar,  Cataract. — This  is  congenital,  or  forms  in 
early  infancy,  and  is  the  most  common  kind  of  cataract  in  children. 
It  usually  is  present  in  both  eyes,  but  it  has  been  seen  in  one  eye 
only.  In  zonular  cataract  the  very  centre  of  the  lens  is  clear 
(Fig.  99,  diagrammatic),  while  around  this  is  a  cataractous  layer 
or  zone,  and  outside  that  again  the  peripheral  layers  are  trans- 
parent.    The    majority    of   these   cases   are   not   progressive,    but 


270  DISEASES    OF   THE  EYE.  [chap.  x. 


occasionally  the  whole  lens  does  become  opaque,  and  usually  then 
there  have  been  previously  some  sliglit  opacities  in  the  otherwise 
clear  cortical  layers. 

With  oblique  illumination,  the  cortical  layers  of  the  lens  are 
seen  to  be  clear,  while  towards  the  centre  of  the  lens 
a  uniform  grey  circular  opacity  will  be  observed.  The 
diameter  of  this  opacity  may  be  small,  perhaps  not  more 
than  3  mm.  or  4  mm.,  or  it  may  extend  very  nearly  to 
^  the  equator  of  the  lens.     If  the  pupil  be   dilated,   and 

the  lens  examined  with  transmitted  light,  the  cataractous 
portion  will  appear  as  a  more  or  less  dark  disc  in  the  centre  of 
the  lens,  while  all  around  it  is  seen  the  red  light  reflected  from  the 
fundus  oculi.  The  centre  of  this  disc  is  either  of  the  same  degree 
of  darkness  as  its  margin,  or  but  very  little  darker  ;  and  this  fact 
serves  to  distinguish  this  form  of  cataract  from  one  in  which  the 
whole  centre  of  the  lens  is  opaque.  In  the  latter  case  it  is  evident 
that  the  centre  of  the  opacity  must  be  darker  than  its  margin.  In 
many  cases  small  radial  opacities  are  seen  round  the  equator  of  the 
lens,  passing  from  the  anterior  to  the  posterior  surface,  their  con- 
cavity embracing  the  circumference  of  the  central  opacity.  They 
are  called  riders  (Fig.  99). 

It  has  been  held  that  lamellar  cataract  is  due  to  some  transient 
disturbance  of  nutrition  in  utero,  occurring  at  the  time  the  affected 
layers  of  the  lens  are  being  laid  down.  But  against  this  view  is  the 
fact  that  one  half  of  the  lens  only  may  present  the  appearance  of 
zonular  cataract.  The  subjects  of  it  are  usually  rachitic,  as  shown 
by  the  irregular  and  imperfect  development  of  the  teeth  (Fig.  100). 
and  by  rachitic  alterations  in  the  bones 
of  the  skull.  Convulsions  during  infancy 
in  these  patients  are  common. 

The  Treatment  of  central  lental  cata- 
ract and  of  zonular  cataract  is  similar, 
and  consists  either  in  elimination  of  the  ^ig.  lOO. 

lens  by  discission  or  in  the  formation  of 

a  narrow  coloboma  downwards  and  inwards  by  means  of  iridec- 
tomy. The  latter  is  very  decidedly  to  be  preferred  in  those  cases 
in  which  the  central  opacity  is  so  small  that,  on  dilatation  of  the 
pupil,  the  acuteness  of  vision,  with  the  aid  of  a  stenop^cic  slit,  is 
increased  in  a  satisfactory  degree.      When   the   improvement  so 


BP^  T?! 


CHAP.  X.]  THE   CRYSTALLINE    LENS.  271 


produced  is  but  slight,  the  operation  of  discission  is  indicated. 
The  advantage  of  iridectomy  over  discission,  when  the  former  can 
be  adopted,  is  that  no  spectacles  are  afterwards  required,  and 
that  the  power  of  accommodation  is  retained. 

Punctate  Cataract. — This  is  a  congenital  form  of  cataract  in  which 
minute,  rather  bhiish  dots  are  scattered  through  the  lens.  It  is  non- 
progressive and  does  not  affect  the  sight  very  much.  It  is  probably  a 
form  of  zonular  cataract. 

Anterior  Polar,  or  Pyramidal,  Cataract  may  be  either  congenital 
or  acquired.  In  the  former  case  it  must  be  referred  to  some  inflam- 
matory disturbance  occurring  about  the  third  period  of  development 
of  the  lens.  In  both  cases  the  mode  of  origin  of  the  opacity  is  the 
same,  whether  it  be  punctiform,  flakelike,  or  pyramidal — namely, 
by  contact  of  the  lens  with  an  inflamed  cornea.  In  foetal  life  this 
may  occur  without  any  perforation  of  the  cornea,  as  there  is  then  no 
anterior  chamber.  Fig  101  shows  a  case,  in  which  in  the  left  eye 
a  filament  connects  the  disc- 
like anterior  polar  cataract 
with  an  opacity  of  the  cor- 
nea. In  the  right  eye  there 
is  a  pyramid-shaped  cataract. 
After  birth  a  perforating  ulcer  Fig.  101. 

of  the  cornea  is  a  neces- 
sary precursor  of  this  form  of  lental  opacity,  but  the  ulcer  need 
not  be  central  (p.  65).  This  contact  with  an  inflamed  and  ulcerating 
cornea  leads  to  subcapsular  cell-proliferation,  at  that  portion  of  the 
capsule  which  is  exposed  in  the  pupillary  area,  and  to  consequent 
subcapsular  opacity  in  this  small  area. 

No  Treatment  is  required,  as  vision  is  not  affected. 

Fusiform,  or  Spindle-Shaped,  Cataract  is  also  congenital,  and  is  rare. 
It  consists  in  an  axial  opacity  extending  from  pole  to  pole,  and  mav  be 
conibined  with  central  or  lamellar  opacity. 

The  foregoing  forms  of  cataract,  with  the  exception,  perhaps,  of  the 
anterior  polar  and  genuine  black  cataract,  are  primary  ;  that  is  to  say, 
they  are  not  dependent  on,  nor  are  they  the  results  of,  disease  in  other 
parts  of  the  eye. 

Posterior  Polar  Cataract.— An  opacity  at  the  posterior  pole  of 
the  lens  may  occur  congenitally. 


272  DISEASES   OF    THE   EYE.  [chap.  x. 


Secondary,  or  Complicated,  Cataract. 

Some  diseased  states  of  tlie  eye  give  rise  to  cataract. 

Of  this  a  partial  kind  is 

Posterior  Polar  Cataract.— Besides  the  congenital  variety, 
posterior  polar  cataract  may  be  acquired.  This  form  is  seen,  with 
transmitted  light,  as  a  star-shaped  or  rose-shaped  opacity  in  the 
most  posterior  layers  of  the  posterior  cortical  substance,  its  centre 
corresponding  with  the  posterior  pole  of  the  eye. 

Posterior  polar  cataract  is  usually  found  in  eyes  which  are  the 
subjects  of  disseminated  chorioiditis,  retinitis  pigmentosa  or 
diseased  vitreous  humour.  It  sometimes  progresses,  and  becomes 
a  complete  cataract ;  and  then  the  prognosis  for  sight  after  extrac- 
tion is  not  very  good,  owing  to  the  disease  which  is  present  in  the 
deep  parts  of  the  eye. 

The  additional  disturbance  of  sight  caused  by  the  presence 
of  posterior  polar  cataract  depends  a  good  deal  upon  its  density. 

Total  Secondary  Cataract  often  ensues  lipon  contact  of  the  lens 
with  inflammatory  products  in  the  eye — e.g.  where  false  membranes 
have  been  produced  by  inflammation  in  the  uveal  tract ;  and  it  is 
called  Cataracta  Accreta,  when  the  iris  or  ciliary  processes  arfi  ad- 
herent to  it.  Cataract  is  also  caused  by  detaefhment  of  the  retina, 
intra-ocular  tumour,  absolute  glaucoma,  dislocation  of  the  lens,  etc. 
The  reason  of  this  is  that  the  nutrition  of  the  lens  becomes  impaired. 

Such  cataracts  often  undergo  a  further  degeneration,  and  become 
calcareous.  Calcareous  cataracts  are  easily  recognised  by  their 
densely  white  or  yellowish-white  appearance  ;  and  almost  always 
indicate  deep-seated  disease  in  the  eye,  even  when  the  functions,  so 
far  as  they  can  be  tested,  are  fairly  good. 

These  secondary  cataracts  rarely  come  within  the  range  of 
Treatment,  as  the  diseases  which  give  rise  to  them  are  usually 
destructive  of  sight.  When,  occasionally,  they  can  be  dealt  with 
they  should  be  extracted. 

The  term  secondary  cataract  is  also  used  in  cases  in  which,  after  a 
cataract  extraction,  the  capsule  of  the  crystalline  lens,  which  is  left 
behind,  presents  an  obstacle  to  good  sight,  but  here  it  is  not  a 
suitable  term.  This  will  be  referred  to  again,  and  does  not  come 
within  the  scope  of  this  paragraph. 


CHAP.  X.]  THE   CRYSTALLINE  LENS..  273 


Capsular  Cataract. 

By  this  term  is  meant  an  opacity  of  the  anterior  capsule,  or  of 
the  capsular  epithelium.  It  is  usually  confined  to  the  centre  or 
anterior  pole,  and  is  most  frequently  seen  in  over-ripe  senile  cataracts, 
and  in  secondary  cataracts. 

Traumatic  Cataract. 

Every  perforating  injury  of  the  eye  which  opens  the  capsule  of 
the  lens  is  liable  to  cause  cataract,  by  reason  of  the  admission  of 
the  aqueous  humour. 

Perforating  injuries  with  sharp  instruments,  or  the  entrance  of 
small  foreign  bodies — in  both  cases,  as  a  rule,  through  the  cornea — 
are  the  most  common  injuries  that  produce  traumatic  cataract. 
Blows  upon  the  eye,  without  any  perforating  wound,  also,  although 
more  rarely,  produce  cataract.  In  these  latter  cases  there  is  a 
rupture  of  the  capsule,  either  at  the  equator  of  the  lens,  or  on  its 
posterior  or  anterior  surface. 

Within  a  few  hours  after  a  perforating  injury  of  the  anterior 
capsule,  the  lens-substance  in  the  immediate  neighbourhood  of  the 
opening  becomes  opaque,  swells,  and  protrudes,  as  a  grey  flufTy- 
looking  mass,  through  the  opening  in  the  capsule  into  the  anterior 
chamber,  where  it  gradually  breaks  up,  dissolves,  and  becomes 
absorbed.  It  is  immediately  followed  by  other  portions  of  the 
lens  which  have  become  cataractous,  until,  after  some  weeks,  the 
whole  lens  will  have  disappeared,  and  the  pupil  will  again  become 
black  ;  and  the  eye  may  now  see  well  with  a  suitable  convex  lens. 
The  swelling  and  absorption  of  the  lens  are  all  the  more  rapid,  the 
larger  the  opening  in  the  capsule  and  the  younger  the  patient. 

But  the  course  of  events  just  sketched  is  the  most  favourable 
one,  and  is  hardly  likely  to  take  place  in  a  case  which  is  wholly  un- 
treated. In  the  first  place  the  swelling  of  the  lens — especially  if, 
in  consequence  of  a  wide  opening  in  the  capsule,  it  be  rapid — is 
liable  to  irritate  the  iris,  and  to  cause  iritis  ;  or  to  push  the  periphery 
of  the  iris  forwards  against  the  periphery  of  the  cornea,  block  the 
angle  of  the  anterior  chamber,  and  cause  secondary  glaucoma 
(p.  256). 

Moreover,  violent  plastic  or  purulent  uveitis  may  come  on,  as  the 
18 


274  DISEASES   OF   THE  EYE.  [chap.  x. 

consequence  of  the  introduction  of  infective  matter  on  the  per- 
foratinjj;  object,  or  foreign  body,  which  causes  the  cataract.  Wliere 
this  occurs,  the  case  enters  the  category  of  diseases  of  the  uveal 
tract ;    and  the  cataract,  as  such,  becomes  a  minor  consideration. 

Again,  we  sometimes  meet  with  traumatic  cataracts  which  do 
not  undergo  absorption,  but  simply  remain  stationary ;  or,  in 
the  course  of  years,  they  may  undergo  secondary  changes,  similar 
to  those  which  occur  in  senile  cataract.  In  these  instances,  the 
trauma  is  usually  a  blow  on  the  eye,  not  a  perforating  injury  : 
and  it  is  believed  that  the  rupture  of  the  capsule  closes  soon  after 
the  blow,  and  hence  no  lens  matter  can  escape  into  the  anterior 
chamber  ;  also,  the  rupture  in  many  of  these  cases  is  probably  at 
the  equator  of  the  lens,  where  the  aqueous  would  not  readily  gain 
access  to  the  lenticular  substance. 

Occasionally,  cataracts  caused  by  blows  on  the  eye  (concussion 
cataracts)  take  the  form  of  posterior  polar  cataracts,  very  similar 
to  those  seen  sometimes  w^ith  chorioiditis  and  retinitis  pigmentosa 
(chap,  xii.),  the  rest  of  the  lens  remaining  transparent.  These  trau- 
matic posterior  polar  cataracts  sometimes  clear  up  spontaneously. 

Where  the  cataract  is  produced  by  a  small  foreign  body,  which 
has  passed  through  the  cornea  and  into  the  lens,  it  is  a  matter  of 
importance,  for  the  prognosis,  to  decide  whether  the  foreign  body  be 
in  the  lens,  or  have  passed  through  it  into  the  deeper  parts  of  the 
eye.  In  the  former  case  we  may  hope  to  extract  it  with  the  cata- 
ractous  lens  ;  while  in  the  latter  case  we  must  fear  that  it  will  set  up 
dangerous  inflammatory  reaction.  In  such  cases  the  lens  should  be 
well  searched  with  focal  illumination,  and  the  transmitted  light 
may  also  be  of  use  ;  but  in  these  traumatic  cataracts  there  are 
often  glittering  sectors  in  their  deep  parts,  which  may  readily  be 
mistaken  for  a  metallic  foreign  body.  If  the  foreign  body  be  of 
steel  or  iron,  the  Rontgen  rays  may  be  employed  for  its  detection 
(chap.  xi.). 

Very  rarely  the  capsule  has  been  opened,  and  yet  the  lens  has 
not  become  opaque  ;  and,  also,  very  rarely,  after  a  perforating 
injury,  the  opacity  which  formed  has  cleared  away  again.  The 
latter  event  is  more  frequently  seen  in  cases  of  traumatic  posterior 
polar  cataract  than  in  other  cases. 

Treatment.— ThQ  pupil  should  be  kept  dilated  with  atropine,  in 
order  to  draw  the  iris  out  of  the  way  of  the  swelling  lens  matter  : 


CHAP.  X.]  THE    CRYSTALLINE   LENS.  275 

and  nothing  more  is  necessary  if  complications  do  not  arise.  But 
should  iritis,  or  high  tension,  come  on — and  the  surgeon  must  con- 
stantly test  the  tension — it  is  important,  without  further  delay,  to 
extract  as  much  as  possible  of  the  cataract.  This  may  be  done 
either  without  an  iridectomy,  through  a  linear  incision  some  10  mm. 
long  in  the  upper  third  of  the  cornea,  or  with  an  iridectomy,  through 
an  incision  in  the  upper  margin  of  the  cornea. 

If  a  foreign  body  be  present  in  the  lens,  extraction  of  the  latter 
with  the  foreign  body  should  invariably  be  undertaken. 

Where  violent  purulent  or  plastic  uveitis  is  set  up  by  the  trauma, 
the  treatment  resolves  itself  into  that  required  for  these  inflamma- 
tions (chap.  vii.). 

Operations  for  Cataract. 

With  regard  to  the  State  of  Health  of  the  Patient  about  to  be  oper- 
ated on  for  senile  cataract  it  is  desirable,  as  in  every  operation,  that 
it  should  be  good.  Yet,  we  have  so  often  in  these  cases  to  deal  with 
very  old  people,  that  we  cannot  in  every  instance  require  sound 
organs  and  a  robust  constitution  ;  and,  as  a  matter  of  experience, 
serious  disease  of  the  heart,  lungs,  and  liver,  even  when  they  all 
existed  in  the  same  individual,  have  not  proved  any  impediment  to 
a  successful  operation.  Diabetes  is  no  absolute  contra-indication, 
although,  as  already  stated,  coma  does  sometimes  ensue,  and  even 
in  the  presence  of  Bright's  disease  a  successful  operation  may  be 
performed.  Very  advanced  years,  even  up  to  one  hundred,  form 
no  obstacle. 

The  State  of  the  Eye  itself  should  be  carefully  investigated  prior 
to  proposing,  or  undertaking,  an  operation  for  cataract,  and  is  a 
more  important  matter  than  the  patient's  general  health.  Above 
all  things,  it  is  to  be  determined  w^iether  there  be  intra-ocular  com- 
plications, which  would  neutralise  the  result  of  a  successful  operation, 
such  as  detachment  of  the  retina,  disseminated  chorioiditis,  atrophy 
of  the  optic  nerve,  etc.  The  examination  of  the  eye  before  the  lens 
has  become  opaque,  if  the  surgeon  have  had  that  opportunity,  will 
provide  the  most  reliable  data  ;  and,  for  this  reason,  a  careful  note 
should  be  taken  of  the  condition  of  the  fundus  in  each  case  of  incipient 
cataract.  The  examination  of  the  fundus  of  the  fellow  eye,  if  its 
lens  be  clear,  may  help  in  determining  the  point,  in  so  far  as  those 


270  DISEASES    OF    THE   EYE.  (chap.  x. 

intra-ociilar  diseases  are  concerned  which  are  apt  to  be  binocular  ; 
but  retinitis  pigmentosa,  which  is  usually  binocular,  is  no  contra- 
indication to  operation.  Again,  the  ccjudition  of  the  anterior 
capsule  of  the  lens  should  be  observed,  for  a  defined  glistening  white 
square  patch,  about  2  mm.  broad,  situated  in  the  centre  of  the  cap- 
sule, tells  the  tale  of  intra-ocular  mischief.  It  cannot  be  confounded 
with  the  more  diffused  striated  and  punctated  capsular  alterations 
due  to  over-ripeness. 

Finally,  the  functions  of  the  eye  should  be  examined.  With 
an  uncomplicated  cataract  of  the  most  opaque  kind,  good  perception 
of  light  should  be  present,  so  that  the  light,  say,  of  a  candle  some 
two  metres  distant  may  be  distinguished.  In  less  dense  cataracts, 
fingers  may  be  counted  at  1  m.  or  1'5  m.,  even  when  full  maturity 
has  been  attained.  The  field  of  vision  must  be  examined  by  means 
of  the  '  projection  '  of  light — i.e.  the  position  of  a  lighted  candle 
held  in  different  parts  of  the  field  should  be  recognised  by  the  patient, 
who  is  required  to  point  his  finger  in  the  direction  of  the  light,  as  it  is 
moved  rapidly  from  one  part  of  the  field  to  another.  This  exami- 
nation is  usually  made  by  means  of  the  light  reflected  from  the 
ophthalmoscope  mirror.  If  the  patient  fail  to  project  the  light  in 
any  direction,  a  diseased  condition  in  the  corresponding  part  of  the 
retina  may  be  suspected.  Yet,  in  cases  of  very  old  uncomplicated 
cataract,  the  patients  often  project  the  light  in  some  one  direction, 
no  matter  where  it  may  come  from.  A  certain  degree  of  intelli- 
gence on  the  part  of  the  patient  is  required  for  this  test. 

By  the  foregoing  means,  most  of  the  intra-ocular  complications 
of  a  serious  nature  can  be  detected  ;  but  there  is  at  least  one  against 
which  there  is  no  safeguard,  namely,  a  small  circumscribed  spot  of 
chorioido-retinal  degeneration  at  the  macula  lutea  (central  senile 
chorioiditis,  p.  192).  After  removal  of  a  cataract  from  an  eye 
affected  in  this  way,  the  patient's  vision  is  so  much  improved  as  to 
enable  him  to  go  about  alone  ;  but  reading  will  still  I'emain  an 
impossibility  for  him,  and  to  that  extent  the  result  of  the  operation 
will  be  a  disappointment  to  patient  and  surgeon. 

The  Cornea  should  be  Examined. — Such  corneal  opacities  as 
would  seriously  compromise  vision  may  contra-indicate  the  opera- 
tion ;  but  slighter  opacities,  discernible  only  with  oblique  illumina- 
tion, would  merely  diminish  the  future  acuteness  of  vision,  and 
would  require  a  corresponding  prognosis  to  be  given  before  operation. 


CHAP.    X.] 


THE    CRYSTALLINE   LENS. 


277 


The  Condition  of  the  Appendages  of  the  Eye,  too,  must  be  ex- 
amined. Should  there  be  any  conjunctivitis,  or  blepharitis,  it  ought 
to  be  cured  or  alleviated,  and  a  bacteriological  examination  should 
then  be  made  before  the  operation  is  undertaken. 

In  cases  of  dacryocystitis,  extirpation  of  the  lacrimal  sac  is 
imperative,  prior  to  a  cataract  extraction.  Should  the  precaution 
be  neglected,  infection  of  the  wound  with  disastrous  results  is  very 
likely  to  ensue. 

Extraction  of  Cataract. 

Linear  Extraction. — The  extraction  through  a  linear  incision 
in  the  cornea  is  applicable  only  to  soft,  or  fluid,  cataracts,  in  persons 
under  the  age  of  twenty-five.  The  instruments  required  are  : — 
A  spring  lid  speculum,  a  fixation  forceps,  a  broad  keratome  or  a 
Grrefe's  cataract  knife,  a  cystotome,  and  a  spatula.  The  pupil  is 
contracted  with  eserine. 

The  eye  having  been  cocainised,  and  the  speculum  applied,  a  fold 
of  conjunctiva  close  to  the  lower  margin  of  the  cornea  is  seized  (Fig. 
102)  with  the  fixation  forceps,  and  the  eye  fixed  by  it  throughout  the 
operation.  The  point  of  the 
keratome  is  now  entered  into 
the  cornea  above  about  4  mm. 
inside  the  margin,  and  is  passed 
into  the  anterior  chamber.  The 
blade  of  the  knife  is  then  laid 
in  a  plane  parallel  to  that  of  the 
iris,  and  pushed  on  until  the 
corneal  incision  has  attained  a 
length  of  6  or  7  mm.  The  point 
of  the  knife  being  now  laid 
close  to  the  posterior  surface  of 
the  cornea — in  order  that  no 
injury  may  be  done  to  the  iris 
or  lens  when  the  aqueous  humour 

commences  to  flow  off — the  instrument  is  very  slowly  withdrawn, 
so  that  the  aqueous  humour  may  come  away  gradually,  w^ithout 
causing  prolapse  of  the  iris.  In  withdrawing  the  knife  it  is  well  to 
enlarge  the  inner  aspect  of  one  or  other  end  of  the  wound,  by  a 
suitable  motion  of  the  instrument  in  that  direction. 


;^S^= 


Fig.   102. 


278 


DISEASES   OF    THE   EYE. 


[chap.  X. 


The  keratome  being  now  laid  aside,  the  cystotome  is  passed  into 
tlie  anterior  chamber  (Fig.  103)  as  far  as  the  opposite  pupillary 
margin,  care  being  taken,  by  keeping  the  sharp  point  of  the  instru- 
ment directed  either  up  or  down,  not  to  entangle  it  in  the  wound 

or  in  the  iris.  The  point  is  now 
turned  directly  on  to  the  anterior 
capsule,  and,  by  withdrawing  the 
z::^z=z^zi.  cystotome  towards  the  corneal 
incision,  an  opening  in  the  cap- 
sule of  the  width  of  the  pupil  is 
produced.  The  cystotome  is  then 
i-emoved  from  the  anterior  cham- 
ber, with  the  same  precautions  as 
^  on  its  introduction. 

The  spatula  is  then  placed  on 
the  outer  lip  of  the  wound,  and 
the  latter  is  made  to  gape  some- 
what, gentle  pressure  being  at  the 
same  time  applied  to  the  inner 
of  the  eye  by  the  fixation  forceps,  and  in  this  way  the 
evacuated.     When  the  pupil  has  become  quite   black  the 


Fig.   103. 


aspect 
lens  is 

operation  is  concluded.  If  pressure  do  not  at  first  clear  the. pupil 
completely,  the  speculum  should  be  removed,  the  eyelids  closed, 
a  compress  applied,  and  a  few  minutes  allowed  to  elapse,  in 
order  that  some  aqueous  humour  may  be  secreted.  A  renewal 
of  the  efforts  to  clear  the  pupil  will  probably  now  be  successful, 
or,  if  not,  another  pause  may  be  made,  and  then  fresh  attempts  em- 
ployed until  the  pupil  is  quite  clear.  Fragments  may  be  fetched 
out  of  the  anterior  chamber  with  the  spatula,  or  better  still  they  may 
be  washed  out  of  it  with  an  irrigator.  Should  some  fragments  be 
left,  no  ill  results  need  necessarily  follow,  although  iritis  is  more  apt 
to  supervene  than  if  the  lens  be  thoroughly  evacuated.  Fragments 
left  behind  become  absorbed.  If  there  be  a  prolapse  of  the  iris 
which  cannot  be  reposed,  it  must  be  abscised. 

The  Combined  Operation  {i.e.  combined  with  an  iridectomy). 
For  success  in  the  cataract  operation,  it  is  necessary,  not  only  to 
select  a  rational  method,  but  also  to  devote  the  utmost  attention 
to  a  series  of  minute  details  in  its  performance.  We  shall  describe 
the  operation  as  we  are  in  the  habit  of  performing  it. 


THE   CRYSTALLINE   LENS.  279 


Preparation  of  the  Patient. — A  gentle  purgative  is  given  the  day 
before  tlie  operation,  so  that  the  bowels  need  not  be  disturbed  for 
two  days  after  the  operation.  The  face  is  washed  with  hot  water 
and  soap,  shortly  before  the  operation. 

Preparation  of  the  Eye. — Just  before  the  operation,  at  intervals 
of  two  minutes,  three  drops  of  a  sterilised  solution  of  adrenaline 
(1  in  1000)  containing  3  per  cent,  of  cocaine  are  dropped  into  the 
eye.  Finally,  the  lids  having  been  everted,  the  conjunctival  sac  is 
thoroughly  washed  out  by  irrigation  with  sterilised  physiological 
solution  of  common  salt,  particular  attention  being  paid  to  the 
fornix  of  each  lid,  and  to  the  inner  and  outer  canthus.  Then  the 
skin  of  the  eyelids  and  immediate  surroundings  of  the  eye  are 
painted  with  tincture  of  iodine  and  the  eyelashes  are  cut  short  so 
as  to  obviate  contact  with  the  knife.  If  the  iodine  be  not  used 
a  piece  of  moistened  sterilising  gauze  should  be  placed  over  the 
patient's  face,  leaving  an  opening  for  the  eye. 

Preparation  of  the  Instruments. — Immediately  before  the  opera- 
tion the  instruments  are  sterilised  by  boiling  and  are  then  plunged 
for  a  moment  into  absolute  alcohol,  laid  on  a  sterilised  porcelain 
tray,  and  covered  with  a  sterilised  cloth,  until  required.  It  is  better 
to  have  the  instruments  dry  when  in  use. 

During  the  Progress  of  the  Operation,  small  pledgets  of  sterilised 
lint,  wet  with  the  sterilised  salt  solution,  are  employed  to  wipe 
away  coagula,  cortical  masses,  etc.,  and  are  not  used  a  second  time. 
An  assistant  should  place  the  instruments  in  the  surgeon's  hand  in 
their  turn,  and  take  out  of  his  hand  those  he  has  used,  in  such  a 
manner  as  to  render  it  unnecessary  for  the  operator  to  look  away, 
even  for  a  moment,  from  the  field  of  operation. 

The  Operation. — A  spring  wire  lid-speculum  is  applied.  The 
eye  is  fixed  with  a  catch  fixation  forceps  by  a  fold  of  conjunctiva  and 
sub- conjunctival  tissue,  below  the  vertical  meridian  of  the  cornea,  or 
a  little  to  one  side  of  this  line  (Fig.  104). 

The  point  of  the  knife  is  entered  just  outside  the  margin  of  the 
clear  cornea,  at  the  outer  extremity  of  an  imaginary  horizontal  line 
which  would  leave  a  third  of  the  corneal  circumference  above  it. 
The  knife  is  then  passed  cautiously  through  the  anterior  chamber, 
and  the  counter-puncture  is  made  just  beyond  the  corneal  margin 
at  the  inner  extremity  of  the  horizontal  line  described  (Fig.  104), 
and  the  incision  is  then  finished  in  the  sclero-corneal  margin  by  a  few 


280  DISEASES   OF   THE  EYE.  [chap.  x. 

slow  to-aiid-fro  motions  of  the  knife.  The  blade  will  then  be  found 
to  be  under  the  conjunctiva,  of  which  a  flap  is  formed  in  cutting  out. 
We  consider  it  a  great  mistake  to  make  a  smaller  incision,  or  to  try 
to  vary  the  size  of  the  incision  according  to  the  presumed  size  of  the 
cataract.  Within  limits,  a  large  incision  heals  as  well  as  a  smaller 
one,  and  it  avoids  the  necessity  for  using  any  undue  pressure  in  the 
delivery  of  the  lens.  While  the  incision  is  being  made,  the  aqueous 
humour  flow^s  off. 

The  Second  Stage  of  the  Operation  consists  in  an  Iridectomy. 
The  fixation  of  the  eye  having  been  given  over  to  the  assistant,  the 
iridectomy  is  performed  by  passing  a  curved  iris  forceps  into  the 
anterior  chamber,  seizing  the  smallest  possible  portion  of  the  sphincter 
of  the  iris  at  a  point  corresponding  with  the  centre  of  the  incision, 
drawing  it  out,  and  with  the  forceps-scissors  excising  a  very  small 
central  bit  of  iris.  This  should  be  done  by  approaching  the  forceps- 
scissors  from  over  the  cornea — i.e.  at  right  angles  to  the  wound — 
the  iridectomy  being  tkus  made  with  one  snip  of  the  instrument, 
and,  if  care  be  taken  to  keep  the  blades  close  to  the  forceps,  a  narrow, 
neat  coloboma  will  be  obtained.  A  Tyrrell's  hook,  instead  of  a 
forceps,  may  be  used  to  draw  out  the  iris,  and  this  stage  of  the 
operation  is  thereby  rendered  less  painful,  as  the  pinching  of  the 
iris  with  the  forceps  causes  pain.  A  small  coloboma,  say  of  2,mm. 
to  3  mm.  in  width,  as  in  Fig.  81,  is  sufficient  to  allow  of  an  easy 
delivery  of  the  lens  by  doing  away  with  the  resistance  of  the  sphincter 
iridis,  and  to  prevent  secondary  prolapse  of  the  iris  {vide  infra)  ; 
and  its  advantages  over  a  wide  iridectomy,  from  an  aesthetic  point 
of  view,  are  obvious.  It  should  be  the  object  of  the  surgeon  to 
obtain  the  smallest  possible  coloboma.  The  procuring  of  a  neat 
coloboma  is  much  facilitated  if,  prior  to  the  operation,  the  pupil  has 
been  contracted  (Fig.  104)  by  the  instillation  of  one  or  two  drops  of 
solution  of  sulphate  of  eserine.  We  now  always  made  a  peripheral 
iridectomy,  leaving  the  sphincter  intact  (see  Glaucoma,  p.  255).  If 
this  be  done  the  delivery  of  the  lens  must  precede  the  iridectomy 
and  eserine  should  not  be  put  in  before  the  operation. 

The  Third  Stage  of  the  Operation  is  the  Capsulotomy.  The 
operator  takes  the  fixation  forceps  from  his  assistant,  who  then 
raises  the  speculum  and  eyelids  slightly  off  the  globe,  in  order  that 
no  pressure  may  be  exerted  on  the  latter  during  the  remainder  of  the 
operation.     The  surgeon,  passing  the  cystotome  into  the  anterior 


CHAP.    X.] 


THE    CRYSTALLINE   LENS. 


281 


chamber,  divides  the  anterior  capsule  of  the  lens  by  two  incisions, 
one  passing  from  the  lower  pupillary  margin  upwards  and  outwards, 
the  other  upwards  and  inwards,  as  far  as  the  anterior  surface  of  the 
lens  can  be  seen,  while 
a  third  incision  is  made 
along  the  upper  peri- 
phery of  the  lens.  An 
extensive  opening  in 
the  capsule  is  of  im- 
portance, because  other- 
wise difficulty  in  de- 
livery of  the  lens  may 
be  experienced,  and  be- 
cause a  small  opening 
renders  the  occurrence 
of  secondary  cataract 
more  likely.  In  divid- 
ing the  capsule  it  is 
important  not  to  dig 
into  the  lens,  as  this, 
in  the  case  of  a  hard 
cataract,  is  apt  to  dislocate  it.  A  rather  oblique  application  of  the 
cystotome  to  the  capsule  is,  for  this  reason,  the  best. 

The  cystotome  as  it  is  withdrawn  may  pull  a  tag  of  the  capsule 
into  the  corneal  wound,  where  it  lies  until  the  end  of  the  operation, 
and  where,  owing  to  its  transparency,  it  may  easily  pass  unnoticed. 
Such  a  tag  acts  as  a  foreign  body,  and  may  subsequently  form  the 
starting-point  of  troublesome  complications. 

Capsule  forceps  have  been  devised  for  the  purpose  of  taking  away 
a  large  portion  of  the  anterior  capsule,  instead  of  merely  dividing 
it ;  but  this  does  not  altogether  obviate  the  danger  of  capsule  in  the 
wound,  nor  does  it  do  away  with  the  likelihood  of  secondary  cataract. 
The  method  has  no  advantages  over  that  just  described,  in  cases 
where  the  capsule  is  not  thickened.  But,  when  the  anterior  capsule 
is  thickened,  and  is  therefore  almost  certain  to  cause  an  obstruction 
to  vision,  it  is  always  desirable  to  tear  away  a  central  portion  of  it 
with  forceps. 

The  Fourth  Stage  is  the  Delivery  of  the  Cataract.  The  eye  is 
drawn  gently  downwards— the  patient  being  called  on  to  assist  in 


Fig.  104. — Cataract  extraction.  Position 
of  the  knife  after  the  counter-puncture  has 
been  made.  Lower  dotted  hne  indicates 
where  the  sclero-corneal  incision  will  be,  and 
the  upper  dotted  line  shows  the  limit  of  the 
conjunctival  flap. 


282  DISEASES   OF    THE   EYE.  [chap.  x. 


this  motion  by  looking  towards  his  feet ;  the  spoon  or  spatula  is 
placed  just  below  the  lower  edge  of  the  cornea,  and  gentle  pressure 
is  exercised  on  this  place,  the  pressure  being  gradually  increased, 
until  the  upper  margin  of  the  lens  presents  itself  in  the  wound,  when, 
the  same  pressure  being  maintained,  the  spoon  is  advanced  over 
the  cornea  towards  the  wound,  pushing  the  lens  before  it  and  out 
through  the  wound.  When  the  greatest  diameter  of  the  lens  has 
passed  the  wound,  the  pressure  of  the  spatula  should  immediately 
be  diminished,  lest  rupture  of  the  zonula  be  caused.  The  fixation 
forceps  and  speculum  are  now  removed  from  the  eye,  and  a  cold 
sterilised  compress  is  laid  on  the  closed  lids. 

It  may  be  noted  that  the  fixation  forceps  and  the  speculum  are 
used  until  this  late  stage  in  the  operation.  Some  operators  employ 
neither  fixation  forceps  nor  speculum  from  beginning  to  end  of 
the  operation  ;  while  others  discard  the  fixation  forceps  when  the 
corneal  section  is  completed,  but  retain  the  speculum  until  after  the 
iridectomy  only,  delivering  the  lens  with  the  finger  placed  on  the 
lower  lid.  The  use  of  the  fixation  forceps  and  speculum  until  after 
the  lens  is  delivered  gives  more  security  and  stability  to  the  operator, 
but  if  escape  of  vitreous  be  feared,  the  speculum  should  be  removed 
before  the  lens  is  delivered. 

The  Fifth  Stage  consists  in  Freeing  the  Pupil  of  any  Cortical 
Masses  which  may  have  been  rubbed  off  in  the  passage  of  the  lens 
through  the  wound,  and  is  what  is  called  the  Toilette  of  the  Wound. 
The  presence  of  cortical  remains  is  recognised  by  the  pupil  not 
having  become  quite  black,  or  by  the  vision  not  being  such  as  it 
ought  to  be  (fingers  counted  at  several  feet),  or  by  inspection  of  the 
cataract  just  removed  showing  that  some  portions  of  it  are  left 
behind.  The  use  also  of  focal  electric  illumination  for  the  detection 
of  cortical  fragments  is  very  advantageous.  If  any  fragments  be 
present,  the  cold  sterilised  compress  having  lain  on  the  eye  for  a  few 
minutes  to  enable  some  aqueous  humour  to  collect,  the  operator, 
facing  the  patient,  raises  the  upper  lid  with  the  thumb  of  the  left 
hand,  and  then,  with  the  first  and  second  fingers  of  the  right  hand 
laid  on  the  lower  lid,  he  makes  light  rotatory  motions  with  this  lid 
over  the  cornea  so  as  to  collect  the  masses  towards  the  pupi),  and 
then  with  a  few  rapid  light  motions  upwards,  with  the  margin  of  the 
lid,  these  masses  are  driven  towards,  and  out  of,  the  w^ound.  Care 
and  delicacy  of  touch  are  required  in  order  to  perform  this  lid- 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  283 

mancBuvre  successfully,  without  rupturing  the  hyaloid  by  undue 
pressure. 

Of  late  we  always  remove  cortical  masses  with  the  irrigator,  which 
leaves  a  beautifully  clear  pupil  and  cleans  the  field  of  operation 
admirably. 

With  an  iris  forceps  the  blood-clots  which  may  adhere  to  the 
wound  are  now  removed. 

The  coloboma  has  now  to  be  seen  to.  The  peripheral  portions 
of  the  iris  corresponding  with  the  ends  of  the  wound  are  apt  to  have 
become  prolapsed  in  the  course  of  the  operation,  and  to  have  dis- 
placed the  angles  of  the  coloboma  upwards.  If  this  be  not  corrected, 
the  prolapsed  portions  of  the  iris  heal  in  the  wound,  and  cause 
bulgings  there  later  on,  the  pupil  in  the  course  of  some  months 
becoming  drawn  up  towards  the  cicatrix.  Hence,  in  every  case, 
even  where  everything  seems  to  be  in  order,  it  is  important  to  pass 
the  narrow  spatula  into  the  anterior  chamber,  and  gently  to  stroke 
down  each  pillar  of  the  coloboma  as  far  as  it  can  be  brought.  The 
instillation  of  eserine,  before  the  commencement  of  the  operation, 
will  cause  the  sphincter  iridis  to  assist  in  producing  the  desired 
result.  Finally,  the  conjunctival  flap  is  spread  out  smoothly  into 
its  place,  so  that  it  covers  the  incision  in  the  corneo-scleral  wound. 
All  this  is  aptly  termed  the  toilette  of  the  wound. 

The  sight  of  the  eye  should  then  be  tested  by  finger  counting, 
as  this  affords  the  patient  satisfaction,  and  lends  him  courage  for  the 
next  few  days  of  strict  quiet.  Patients,  especially  those  for  whom 
cataracts  with  yellowish  or  orange-coloured  nucleus  have  been 
extracted,  often  state  now  that  all  objects  seem  to  them  to  be  of  a 
deep  blue  colour.  This  is  a  contrast  effect,  due  to  the  elimination 
of  the  yellow  medium  through  which  light  had  reached  the  retina. 
A  drop  of  eserine  solution  is  instilled,  to  provide  further  security 
against  prolapse  of  iris.  Finally,  the  conjunctival  sac  is  flooded 
with  the  sterilised  saline  solution. 

The  dressing  is  now  applied.  A  piece  of  dry  sterilised  lint, 
sufficiently  large  to  extend  J  inch  beyond  the  orbital  margin  in 
every  direction,  is  laid  on  the  closed  eyelids.  Pieces  of  sterilised 
absorbent  cotton-wool  are  laid  on  this,  the  hollows  at  the  inner 
canthus,  etc.,  being  carefully  filled  up  ;  so  that,  when  the  bandage 
is  applied,  it  may  exert  equal  and  gentle  pressure  on  every  part  of 
the  eye.     Three  turns  of  a  narrow  roller  bandage  over  the  dressing 


284  DISEASES    OF    THE   EYE.  [chap.  x. 

and  round  the  head  are  applied  ;  but  various  other,  and  doubtless 
equally  good,  forms  of  bandage  are  in  use.  The  pressure  of  the 
bandage  need  only  be  sufficient  to  maintain  the  dressing  firmly  in 
its  place.     The  othei  eye  is  closed  by  a  light  bandage. 

A  few  surgeons  think  it  safer  to  perform  a  preliminary  iridectomy 
some  days  or  weeks  before  extracting  the  lens,  but  in  addition  to  the  dis- 
adv'antage  of  submitting  the  patient  to  two  operations  instead  of  one, 
it  renders  difficult  the  subsequent  making  of  a  conjunctival  flap,  and  is 
liable  to  cause  adhesion  of  the  pillars  of  the  iris  in  the  angle  of  the  wound. 

Accidents  liable  to  occur  during  the  Operation. — The  Incision  may  be 
made  Too  Short,  and  the  delivery  of  the  lens,  consequently,  may  be  so 
difficult  that  the  margins  of  the  wound  become  contused,  and  consequently 
suppuration  may  be  promoted.  The  zonula,  too,  may  be  ruptured  by 
the  excessive  pressure  used  to  force  the  lens  out  through  the  narrow 
aperture,  and  prolapse  of  the  vitreous  may  ensue.  If  the  directions  above 
given  be  carefully  attended  to,  the  vast  majority  of  both  hard  and  soft 
cataracts  may  be  extracted  without  difficulty  ;  but  should  the  wound  be 
made  too  small,  it  can  best  be  enlarged  by  the  forceps-scissors,  or  a  blunt- 
pointed  knife  made  for  the  purpose. 

The  iris  may  come  forward  in  front  of  the  knife  edge  when  making 
the  incision.  In  such  a  case  it  may  be  made  to  recede  by  drawing  the 
eyeball  forwards  with  the  knife  ;  if  the  aqueous  have  escaped,  the  knife 
may  be  withdrawn  and  a  spatula  inserted  with  which  the  iris  can  be  pro- 
tected, while  the  knife  is  reintroduced  for  the  completion  of  the  section. 

Haemorrhage  into  the  Anterior  Chamber  may  take  place.  It  may  be 
from  the  iris,  from  the  corneo -sclerotic  margin,  or  from  the  conjunctiva. 
The  blood  can  be  best  removed  with  the  irrigator,  or  if  it  be  not  available 
pressure  with  the  spatula  on  the  cornea,  which  causes  the  wound  to  gape, 
is  often  successful  in  clearing  the  chamber  of  blood,  which  might  interfere 
with  accurate  division  of  the  capsule.  Yet,  when  this  cannot  be  com- 
pletely got  rid  of,  the  capsulotomy  can  be  performed  by  the  exercise  of 
greater  care.  Adrenaline  dropped  into  the  eye  aids  in  arresting  the 
bleeding. 

Prolapse  of  the  Vitreoife  Humour.  This  accident  may  be  caused  by 
undue  pressure  made  on  the  eyeball  by  the  speculum,  fixation  forceps, 
or  spatula,  or  by  the  lower  lid  during  the  lid-manoeuvre.  It  may  be  due 
to  defective  zonula  with  fluid  vitreous  humour.  In  other  cases  it  may  be 
caused  by  the  patient,  who  "  squeezes  "  the  eye  by  contraction  of  the 
orbicularis.  The  best  way  to  deal  with  "  sc[ueezers,"  short  of  using  an 
anaesthetic,  is  to  remove  the  speculum,  and  get  an  assistant  to  put  firm 
pressure  on  the  eyebrow  with  the  fingers  of  one  hand,  which  at  the  same 
time  draws  the  upper  eyelid  well  up,  while  the  lower  eyelid  is  drawn  apart 
with  the  thumb  of  the  other  hand.  When  the  vitreous  prolapses  prior 
to  delivery  of  the  lens,  the  latter  falls  back  into  the  eye,  and  can  orly  be 
delivered  by  at  once  drawing  it  out  with  a  vectis  ;  and  the  accident  is 
one  of  the  most  serious  which  can  occur  in  tlio  course  of  the  operation, 
for  it  is  often  impossible  to  reach  the  lens  witli  the  \ectii;  without  doing  such 


CHAP.  X.]  THE    CRYSTALLINE   LENS.  285 


damage  to  the  eye  that  sight  is  lost.  Loss  of  vitreous  after  deUvery  of 
the  lens  is  less  serious  ;  indeed,  a  considerable  portion  of  the  vitreous  may 
then  escape  without  ill  result  to  the  eye  ;  yet  it  increases  the  traumatism, 
and  renders  inflammatory  reaction  more  liable  to  occur.  Opacities  in  the 
posterior  chamber  of  the  eye  are  frequently  an  ultimate  rcvsult  of  loss  of 
vitreous  ;  but  a  much  more  serious  consequence  is  sometimes  seen  in 
detachment  of  the  retina. 

Collapse  of  the  Cornea.  In  some  cases,  especially  in  old  people,  the 
cornea,  instead  of  retaining  its  curvature,  falls  into  folds,  and  lies,  more  or 
less  flattened,  on  the  iris.  This  is  not  of  any  consequence,  as  the  cornea 
becomes  restored  to  its  usual  shape  when  the  anterior  chamber  is  formed. 

Normal  After -Progress. — Soon  after  the  completion  of  a  normal 
operation,  the  effect  of  the  cocaine  having  passed  off,  some  smarting 
commences,  and  continues  for  four  or  five  hours.  After  that  time, 
the  patient  has  no  unpleasant  sensation  in  the  eye,  unless  it  be  some 
itching,  or  a  slight  momentary  pain,  or  sensation  of  a  foreign  body, 
especially  when  the  eye  is  moved  under  the  bandage.  The  first 
dressing  is  made  in  forty-eight  hours,  in  a  manner  similar  to  that 
immediately  after  the  operation,  a  drop  of  atropine  being  instilled, 
as  also  at  each  successive  dressing  ;  and  the  sterilised  salt  solution 
is  used  for  freely  w^ashing  the  margins  of  the  eyelids,  some  of  it 
being  allowed  to  trickle  into  the  conjunctival  sac.  At  this  first 
dressing,  it  is  w^ell  to  abstain  from  a  very  minute  or  lengthened 
examination  of  the  eye  ;  but,  if  the  lid  be  gently  raised,  the  w^ound 
will  be  found  closed,  the  cornea  clear,  the  anterior  chamber  com- 
pletely restored,  and  the  pupil  semi-dilated  and  black.  The  sub- 
sequent dressings  are  made  night  and  morning,  for  the  purpose  of 
instilling  atropine.  On  the  third  day  after  the  operation  the  patient 
may  be  allowed  to  sit  up,  the  room  being  kept  moderately  dark  ; 
and  on  the  fifth  or  sixth  day  the  bandage  may  be  left  aside  perman- 
ently, and  dark  glasses  w^orn  in  its  stead.  In  the  course  of  a  few 
more  days  the  patient,  having  been  gradually  accustomed  to  more 
light,  may  be  allowed  out  of  doors.  It  is  desirable  to  continue  the 
use  of  atropine  for  about  a  fortnight  longer,  or  until  all  abnormal 
vascular  injection  of  the  white  of  the  eye  has  disappeared,  as  until 
then  there  is  danger  of  iritis.  (For  selection  of  glasses  in  aphakia 
see  end  of  this  chapter.) 

Irregularities  in  the  Process  of  Healing. — The  pain  may  continue  longer 
than  four  or  five  hours,  and  it  is  then  well  to  give  a  hypodermic  injection 
of  morphia  in  the  corresponding  temple,  so  that  the  patient  may  not  be 


286  DISEASES    OF    THE   EYE.  [chap.  x. 

restless.  Should  severe  pain  come  on  some  hours  later,  it  is  apt  to  be  due 
to  an  accumulation  of  tears  under  the  eyelids,  and  it  immediately  subsides 
on  the  bandage  being  removed,  and  exit  given  to  the  tears  by  slightly 
opening  the  eye. 

Post-operative  Conjunctivitis. — Conjunctivitis  in  varying  degrees  of 
severity  is  liable  to  occur  at  times.  The  very  fact  of  bandaging  the  eye 
tends  to  favour  the  development  of  any  organisms  present  in  the  con- 
junctiv^al  sac,  by  diminishing  the  cleansing  lid  movements  and  the  secre- 
tion of  tears,  as  well  as  by  increasing  the  temperature.  The  use  of  too 
strong  antiseptics  also  promotes  its  development,  or  lens  matter,  blood- 
clots,  etc.,  left  lying  in  the  conjunctival  sac. 

Late  Appearance  of  the  Anterior  Chamber. — At  the  first  dressing  it 
will  sometimes  be  found  that  there  is  no  anterior  chamber,  although  the 
appearance  of  the  wound  is  satisfactory  ;  but  this  need  occasion  no  alarm, 
as  the  anterior  chamber  is  sometimes  not  restored  for  three  or  foiu-  days. 
Should  the  anterior  chamber  be  slow  in  forming,  it  is  only  necessary  to 
remove  the  bandage  and  substitute  a  wire  mask  or  shield,  when  closure 
of  the  wound  usually  takes  place.  But  in  some  of  these  cases  a  down- 
growth  of  corneal  epithelium  may  take  jjlace,  w'hich  may  spread  over  the 
whole  of  tlie  iris  and  anterior  chamber  and  may  cause  glaucoma. 

Striped  Keratitis.  At  the  first  dressing,  also,  it  may  sometimes  be 
observed  that  there  is  a  more  or  less  well-marked  striated  cloudiness  of 
the  cornea,  extending  over  nearly  the  whole  of  it,  or  occupying  only  a 
part  in  the  immediate  neighbourhood  of  the  wound.  This  opacity  is 
held  by  some  to  be  the  result  of  injury  to  the  endothelium  of  the  posterior 
surface  of  the  cornea  during  the  operation.  It  is  this  endothelium  which 
protects  the  cornea  from  being  infiltrated  by  the  aqueous  humour,  and  the 
appearance  we  call  striped  keratitis  is  caused  by  oedema  of  the  colrnea. 
According  to  another  explanation,  striped  keratitis  is  due  to  folding  of 
the  posterior  layers  of  the  cornea,  on  account  of  the  difference  in  tension 
in  the  vertical  and  horizontal  directions.  Striped  keratitis  is,  for  the 
most  part,  of  no  serious  import,  as  it  usually  passes  away  in  a  few  days, 
and  leaves  the  cornea  perfectly  clear. 

Expulsive  Haemorrhage.  Soon  after  the  operation — it  may  be  before 
the  patient  is  removed  from  the  couch — great  pain  sets  in.  On  removal 
of  the  dressings  they  are  found  to  be  saturated  with  blood,  while  the 
corneal  flap  is  turned  downwards,  the  wound  is  gaping,  and  througli  it 
blood-clot,  vitreous,  and  iris  protrude.  The  haemorrhage  is  from  the 
retinal  or  cliorioidal  blood-vessels  which  are  atheromatous.  The  accident, 
which  is  rare,  cannot  be  foreseen,  and  the  eye  is  always  lost. 

Septic  Infection.  With  careful  aseptic  measiu-es  this  is  a  rare  event. 
Wlien  it  occurs,  it  usually  does  so  between  the  twelfth  and  thirty-sixth 
hour  after  the  operation,  rarely  earlier  or  later,  and  is  very  serious  ;  for, 
in  the  vast  majority  of  cases,  do  the  surgeon  what  he  may,  it  leads  to  the 
loss  of  the  eye.  Its  onset  is  usually  made  known  by  severe  pain  of  a  con- 
tinuous aching  kind  in  and  about  the  eye  ;  and  it  is  thus  easily  distin- 
guished 'from  tlie  slight,  short,  stabbing  pain,  with  long  intermissions, 
and  gradually  diminishing  intensity,  which  some  patients  complain  of, 
and  whicli  lias  no  evil  import.     On  removing  the  bandage  the  margin  of 


THE    CRYSTALLINE   LENS.  287 


the  upper  lid  will  be  found  oedematous,  the  eye  full  of  tears,  and  the  wound 
covered  with  a  layer  of  muco-pus,  which  can  be  removed  with  the  forceps 
in  one  mass,  while  the  aqueous  humour  and  cornea  may  already  present 
some  opacity.  In  some  hours  more,  the  corneal  opacity  increases  con- 
siderably, the  iris  becomes  distinctly  inflamed,  and  the  pupil  filled  with 
a  mass  of  inflammatory  exudation.  In  many  instances  the 
attack  commences  as  septic  iritis.  The  inflammatory  process 
may  remain  confined  to  the  wound  and  iris,  and  when,  in 
the  course  of  some  weeks,  it  entirely  subsides,  it  leaves  the 
pupil  drawn  up  towards  the  wound  so  that  an  appearance 
as  in  Fig.  105  is  presented.  Or,  the  inflammation  may  strike 
into  the  ciliary  body  and  chorioid,  and  produce  purulent  panophthalmitis 
with  total  destruction  of  the  eye. 

The  pneumococcus  is  the  most  frequent  cause  of  septic  inflammation, 
but  staphylococci  and  streptococci  are  sometimes  responsible  for  it.  Owing 
to  the  vascularity  of  the  conjunctiva,  sepsis  is  less  liable  to  occur  with  a 
conjunctival  flap  than  with  a  purely  corneal  incision. 

To  combat  Septic  Infection  the  best  method  is  the  immediate  cauterisa- 
tion of  the  corneal  wound,  if  it  be  the  seat  of  the  process,  in  its  whole 
extent,  with  the  galvano-cauter5^  Also,  the  wound  may  be  opened  up 
from  end  to  jend  with  a  spatula,  the  aqueous  humour  evacuated,  and  the 
anterior  chamber  washed  out  with  injections  of  sublimate  solution  1  in 
10,000,  while  the  conjunctival  sac  is  irrigated  with  the  same  solution. 
If  necessary  these  measures  are  to  be  repeated  at  intervals  of  eight  or  ten 
hours.  Good  results  have  been  obtained  from  use  of  the  staphylococcus 
vaccine.  Sub-conjunctival  injections  of  solution  of  sublimate  1  in  2,000, 
or  of  oxycyanide  of  mercury  1  in  5,000,  are  often  of  use  in  these  cases,  if 
they  be  commenced  very  soon  after  the  onset  of  the  attack.  Half  a  c.cm. 
is  to  be  injected  as  far  back  as  possible  under  the  conjunctiva  once,  or 
even  twice,  in  twentj-four  hours  ;  and  from  four  to  eight  injections  are 
usually  needed  according  to  the  severity  of  the  case.  Intense  chemosis 
and  much  pain  are  caused.  To  prevent  the  painfulness  of  the  injection, 
five  drops  of  a  1  per  cent,  solution  of  acoine  may  be  added  to  the  quantity 
cf  oxycyanide  of  mercury  solution  injected,  or  to  the  sublimate  injection 
a  few  drops  of  2  per  cent,  cocaine  solution.  Nevertheless  very  severe 
radiating  pain  usually  comes  on  a  quarter  of  an  hour  later,  and  continues 
for  several  hoiu-s.  Hot  fomentations  afford  some  relief  from  this  pain. 
The  patient  should  be  confined  to  bed,  and  a  dressing  should  be  applied 
to  the  eye. 

Plastic  Iritis.  A  few  days  after  the  operation  plastic  iritis,  sometimes 
of  a  severe  type,  may  come  on.  It,  too,  must  be  reckoned  as  due  to 
infection  during  the  operation,  especially  if  some  lens-substance  have 
remained,  for  the  latter  is  a  favourable  nidus  for  the  cultivation  of  infective 
material.  The  iritis  is  ushered  in  with  the  usual  symptoms  of  pain. 
General  plastic  uveitis  may  ensue,  and  sympathetic  uveitis  may  result. 
It  is  said  that  a  mild  iritis  may  be  caused  by  the  staphylococcus  albus. 
Treatment  consists  in  strict  confinement  to  a  dark  room,  with  atropine, 
and  sub-conjunctival  mercurial  injections,  and  quinine  or  large  doses  of 
salicylate  of  soda  internally. 


.288  DISEASES   OF    THE   EYE.  [chap.  x. 

Detachment  of  the  Chorioid.  Fuchs  has  pointed  out  that  detachment 
of  the  chorioid  occurs  some  days  after  cataract  extraction,  in  some  of 
those  cases  in  which  the  anterior  chamber  does  not  form  ;  or  in  which, 
having  formed,  it  becomes  empty  again.  Detachment  of  the  chorioid 
occurs  occasionally  after  iridectomy  unconnected  with  cataract  extraction. 
It  can  be  seen  with  the  ophthalmoscope,  and  sometimes  even  with  focal 
illumination.  Vision  while  the  lesion  is  at  its  height  is  seriously  affected, 
but  the  prognosis  is  good,  for  the  detached  portion  always  becomes  reposed. 
Cystoid  Cicatrix.  After  convalescence,  the  cicatrix  in  the  corneal 
margin  sometimes  becomes  prominent  and  semi-transparent,  presenting 
the  appearance  of  a  vesicle,  and  may  attain  a  large  size.  The  extremities 
of  the  incision  are  the  most  common  positions  for  this  condition,  but  it 
may  occupy  the  entire  length  of  the  cicatrix.  It  does  not  generally  appear 
for  some  weeks,  or  more,  after  the  operation.  In  some  cases  it  is  caused 
by  a  tag  of  iris  which  is  incarcerated  in  the  wound  ;  but  in  other  cases  by 
a  small  piece  of  capsule,  which  has  similarly  healed  in  the  wound.  Irregu- 
larity in  curvature  of  the  cornea,  and  consequent  irregular  astigmatism, 
are  the  least  of  its  evil  consequences.  If  the  condition  be  caused  by  in- 
carceration of  iris,  the  pupil  will  be  gradually  drawn  close  to  the  upper 
corneo-sclerotic  margin  ;  while,  if  it  be  caused  by  a  portion  of  capsule, 
irido-cyclitis  may  be  produced.  Whether  the  iris  or  the  capsule  be  the 
cause,  these  eyes  are  always  exposed  to  the  danger  of  a  sudden  onset  of 
purulent  irido-chorioiditis  (p.  192).  All  this  demonstrates  the  immense 
importance  of  attention  to  those  details  of  the  operation,  which  are  calcu- 
lated to  obviate  incarceration  of  iris,  or  of  capsule,  in  the  cicatrix. 

Cataract  Extraction  without  Iridectomy,  or,  as  it  is  more  com- 
monly termed,  The  Simple  Operation.— This  method  differs  from 
the  Combined  Operation,  in  that  the  incision  occupies  a  greater 
extent  (about  one-third)  of  the  circumference  of  the  cornea,  and 
that  no  iridectomy  is  made.  The  round  pupil,  and  consequent 
prettier  appearance  of  the  eye,  and  the  diminished  tendency  to  loss 
of  vitreous,  and  to  incarceration  of  the  capsule,  are  the  advantages 
this  procedure  has  over  the  Combined  Operation  as  above  described  ; 
for  vision  with  a  circular  pupil  is  not  appreciably  better  than  where 
a  narrow  coloboma  has  been  made. 

On  the  other  hand,  the  extraction  without  iridectomy  exposes 
the  eye  to  the  serious  danger  of  prolapse  of  the  iris  into  the  wound 
some  hours,  or  days,  after  the  operation.  An  iridectomy  must  be 
made  in  all  cases  in  which  the  iris  cannot  be  satisfactorily  reposed 
after  delivery  of  the  lens.  These  cases  are,  however,  few  in  number. 
But,  even  when  the  iris  can  be  well  reposed,  security  against  the 
occurrence  of  a  prolapse  within  the  first  two  or  three  days  after  the 
operation  is  not  obtained  ;    nor  does  eserine,  nor  anv  other  means, 


X.]  THE    CRYSTALLINE   LENS.  280 


provide  the  desired  safeguard.  Prolapse  of  the  iris  does  take  place 
after  a  number  of  these  operations,  and  there  is  no  means  of  fore- 
telling in  what  eyes  it  will  occur.  The  prolapsed  j^ortion  of  iris 
heals  in  the  wound,  which  then,  in  a  few  weeks,  becomes  more  or 
less  cystoid  and  bulging,  causing  displacement  of  the  pupil  and 
irregular  curvature  of  the  cornea,  with  resulting  deterioration  of 
vision.  Nor  is  this  all ;  for  such  eyes  are  liable — weeks,  months, 
or  even  years  after  the  operation — to  take  on  severe  irido-cyclitis, 
ending  in  total  loss  of  sight.  Another  disadvantage  of  the  operation 
is  that  removal  of  cortical  remains  cannot  be  so  effectually  per- 
formed as  where  a  coloboma  has  been  made. 

Why  it  is  that  in  the  simple  extraction  prolapse  of  the  iris  with 
subsequent  incarceration  is  more  liable  to  occur,  even  some  days 
after  the  operation,  than  in  the  combined  operation,  and  why  it  is 
difficult  to  devise  a  sure  means  for  preventing  the  accident,  as,  also, 
how  even  a  very  narrow  coloboma  is  almost  ahvays  sufficient  to 
protect  the  eye  from  this  accident,  can  be  explained  as  follows  : — 
Within  a  few  hours  after  the  operation  the  wound  in  the  corneal 
margin  commonly  closes,  the  aqueous  humour  collects,  and  the 
anterior  chamber  is  restored.  But  it  takes  many  hours  more  for  the 
delicate  union  of  the  lips  of  the  wound  to  become  quite  consolidated, 
and  during  this  time  it  requires  but  a  slight  thing — a  cough,  a  sneeze, 
a  motion  of  the  head,  the  necessary  efforts  in  the  use  of  a  urinal  or 
bed-pan,  no  matter  how  careful  the  nursing — to  rupture  the  newdy 
formed  union  ;  and,  as  a  matter  of  fact,  this  often  does  take  place. 
The  aqueous  humour  then  flows  away  through  the  wound  with  a 
sudden  gush,  and,  where  the  simple  extraction  has  been  employed, 
carries  with  it  the  iris.  It  is  the  aqueous  humour  behind  the  iris 
which  is  chiefly  concerned  in  the  iris-prolapse. 

The  formation  of  even  a  narrow  coloboma  prevents  prolapse  of 
the  iris  when  the  wound  is  ruptured,  but  this  is  not  because  the 
portion  of  iris  which  is  liable  to  prolapse  has  been  taken  away, 
for  that  would  be  nothing  less  than  the  whole  of  that  part  of  the 
iris  which  corresponds  with  the  length  of  the  wound.  The  coloboma 
averts  secondary  iris-prolapse,  by  providing  a  way  for  the  aqueous 
humour  contained  in  the  posterior  part  of  the  anterior  chamber  to 
escape  directly  through  the  w^ound,  without  carrying  with  it  the 
iris  in  its  rush  ;  and  the  narrowest  coloboma  which  can  be  formed 
is  sufficient  for  the  purpose. 
19 


290  DISEASES   OF   THE   EYE.  L^hap.  ^. 

But  all  the  advantages  of  the  simple  operatiou,  without  the 
danger  of  prolapse,  can  be  obtained  by  making  a  small  peripheral 
iridectomy  or  simple  incision  of  the  iris,  which  leaves  the  sphincter 
intact.  When  this  procedure  is  adopted,  the  lens  is  delivered  before 
the  iridectomy  is  made. 

Extraction  in  the  Capsule. — The  ideal  cataract  extraction  is 
that  in  which  the  opaque  lens  in  its  capsule  is  removed,  thereby 
obviating  all  subsequent  troubles  due  to  the  capsule.  The  objection 
which  has  prevented  the  method  from  coming  into  general  use  is 
the  great  danger  of  prolapse  of  vitreous  which  must  attend  it,  owing 
to  the  liability  of  the  hyaloid  membrane  to  be  ruptured  during 
delivery  of  the  cataract.  The  operation  has  been  performed  by 
ophthalmic  surgeons  from  time  to  time,  and  has  been  more  especially 
cultivated  in  India  by  Major  Henry  Smith.  His  incision  lies  in  the 
cornea  about  3  mm.  below  its  upper  margin,  the  puncture  and 
counter-puncture  being  in  the  corneo-scleral  margin,  as  peripherally 
as  possible.  The  speculum  is  then  removed,  and  the  assistant  raises 
the  upper  lid  w^ith  a  strabismus  hook,  at  the  same  time  drawing  the 
eyebrow  and  upper  lid  upwards,  with  firm  pressure  of  the  fingers, 
while  the  lower  lid  is  drawn  down  with  the  other  hand.  The  curve 
of  a  strabismus  hook  is  placed  on  the  cornea  in  its  lower  third,  and  a 
Daviel's  spoon  just  above  the  upper  edge  of  the  wound.  With  these 
instruments  gentle  pressure  and  counter-pressure  are  made,  until 
the  lens  is  more  than  half  delivered  ;  it  is  then  tilted  with  the  hook, 
and  the  delivery  is  completed.  The  operation  may  be  done  with  or 
without  iridectomy,  but  must  be  performed  slowly  and  cautiously, 
else  the  lens  capsule  may  be  ruptured,  and  the  object  of  the  method 
frustrated.  Major  Smith,  in  a  large  number  of  cases,  had  loss  of 
vitreous  in  only  6*6  per  cent.  This  method  is  still  on  its  trial  in 
Europe  and  has  not  met  with  universal  approval. 

Mental  Derangements  after  Cataract  Extractions. — After  cataract  ex- 
tractions, during  the  period  of  confinement  to  bed,  passing  mental  dis- 
turbance is  sometimes  seen  in  old  people.  This  usually  takes  the  form 
of  confusion  of  ideas,  hallucinations,  and  terror.  It  is  hard  to  assign  a 
cause  for  it,  but  probably  it  is  mainly  due  to  the  quiet,  and  to  the  exclusion 
of  light  if  a  binocular  bandage  have  been  applied,  following  on  a  period 
of  some  anxiety  and  excitement.  A  few  doses  of  sulphonal,  and  permis- 
sion to  sit  up — at  least  in  bed — with  removal  of  the  bandage  from  the 
unoperated  eye,  will  be  the  best  measures  to  adopt  in  such  a  case  ;  and 
speedy  restoration  of  mental  equilibrium  may  be  looked  for  with  confidence. 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  291 

Care  should  be  taken  not  to  mistake  the  symptoms  of  atropine  poisoning 
for  this  form  of  mental  disturbance. 

Secondary  Glaucoma  after  Cataract  Extraction  occurs  now  and  then,  by- 
whatever  method  the  extraction  may  have  been  performed.  This,  per- 
haps, is  contrary  to  what  would  be  expected,  in  view  of  the  diminished 
contents  of  the  globe,  and  especially  where  an  iridectomy  has  been  made. 
High  tension  in  these  instances  may  come  on  soon  after  recovery  from 
the  cataract  operation,  or  after  a  good  result  has  existed  for  a  consider- 
able time.  It  is  due  in  some  cases  to  the  corneal  epithelium  growing  into 
the  wound  and  into  the  anterior  chamber,  where  it  spreads  over  the  angle 
of  the  latter,  and  occludes  the  ways  of  exit.  It  is  associated  then  with 
slow  formation  of  the  anterior  chamber  (see  above).  Glaucoma  may  also 
arise  from  blocking  of  the  angle  of  the  anterior  chamber  by  accumulations 
of  cells  in  cases  of  extraction  followed  by  iritis  with  punctate  deposits. 
Or  again  there  may  be  adhesion  of  the  capsule  or  hyaloid  membrane  to 
the  w^ou^nd.  In  the  latter  case  division  of  the  capsule  along  the  inner 
surface  of  the  wound  is  indicated,  otherwise  trephining  or  iridectomy 
should  be  done. 

Erythropsia  after  Cataract  Operations.  For  an  account  of  this  see 
chap.  xiv. 

Secondary  Cataract. — The  term  secondary  cataract,  as  here 
employed  (compare  p.  272),  usually  means  a  closure  of  the  opening 
which  is  present  in  the  anterior  capsule  after  the  removal  of  a  cata- 
ractous  lens,  combined  with  a  thickening  of  the  capsule  in  some 
cases,  whereby  an  impediment  is  offered  to  the  rays  of  light  in 
passing  through  the  pupil.  The  thickening  may  have  pre-existed 
in  the  capsule,  or  it  may  be  due  to  subsequent  proliferation  of  the 
epithelial  cells  on  the  inner  surface  of  the  capsule.  Or,  without 
becoming  thickened,  the  capsule  may  become  wrinkled,  and  cause 
irregular  refraction  of  the  rays  entering  the  eye  and  consequent 
lowering  of  the  vision.  The  term  is  also  applied  to  those  cases  in 
which,  after  cataract  extraction,  an  exudation  in  the  pupil,  following 
upon  iritis,  has  occurred.  Finally,  and  very  incorrectly,  it  is  applied 
to  the  cases  which  Fig.  105  represents,  in  which,  after  suppuration 
of  the  wound  with  irido-cyclitis,  the  iris  is  dragged  upwards,  and  the 
pupil  is  consequently  obliterated. 

The  most  simple  form  of  secondary  cataract  occurs  as  a  very  fine 
cobweb-like  membrane — the  capsule  of  the  lens — extending  over 
the  whole  area  of  the  pupil,  which  can  often  only  be  discovered  by 
careful  examination  with  oblique  illumination.  It  may  not  cause 
any  trouble  of  vision  until  some  months  after  the  extraction,  when 
a  little  thickening  or  wrinkling  of  it  may  have  taken  place. 

lotomy,  as  the  operation  for  making   a   clear  opening  in 


202  DISEASES   OF    THE  EYE.  [chap.  x. 

this  membrane  is  called,  is  performed  with  a  Knapp's  needle-knife. 
This  instrument  has  a  blade  4J  mm.  in  length.  It  cuts  on  one  side 
only,  and  the  blade  and  the  evenly  rounded  shaft  are  so  proportioned 
that  the  shaft  fills  exactly  the  opening  made  by  the  blade,  and  con- 
sequently the  needle  can  be  moved  within  the  anterior  chamber 
in  every  direction,  without  escape  of  aqueous  or  bruising  of  the 
cornea.  Tlie  instrument  must  be  of  the  utmost  sharpness  in  point 
and  edge,  so  that  it  may  cut,  and  not  tear.  The  point  of  the  needle- 
knife  is  entered  subconjunctivally  into  the  anterior  chamber,  and 
made  to  pierce  the  capsule,  and  with  one  sweeping  motion  of  the 
blade  an  opening  is  cut  in  it,  hard  and  inelastic  bands  being  avoided. 
Ziegler's  knife  is  also  a  useful  instrument,  and  for  tough  membranes 
a  better  one.     With  it  a  sawing  motion  is  used. 

Iridotomy  is  the  operation  used  for  cases  (as  in  Fig.  105)  where 
the  iris  forms  a  complete  ^nd  tightly  stretched  curtain  across  the 
pupil.  A  vertical  incision  having  been  made  in  the  cornea,  about 
3  mm.  long,  and  the  same  distance  removed  from  its  inner  margin, 
the  closed  blades — one  of  which  has  a  sharp  point — of  de  Wecker's 
forceps-scissors  are  passed  into  the  anterior  chamber.  The  blades 
are  then  opened,  and  the  sharp  point  of  one  of  them  is  forced  through 
the  stretched  iris,  and  some  3  or  4  mm.  behind  it.  By  closing  the 
blades  the  tightened  iris  fibres  are  cut  across,  and  on  their  retraction 
a  central  clear  pupil  is  formed  in  the  iris  and  retro-iridic  tissue. 

Another  method  consists  in  making  two  oblique  incisions  in  the 
iris  with  the  scissors  from  either  angle  of  the  wound,  these  incisions 
meet  below,  thus  isolating  a  Y-shaped  portion  of  iris  which  can  be 
grasped  with  a  forceps  and  excised  at  its  base  above.  With  the  object 
of  preventing  loss  of  vitreous,  Elsching  does  a  similar  operation,  but 
introduces  the  scissors  through  two  small  incisions  made  by  trans- 
fixion of  the  cornea  with  a  cataract  knife. 

Ziegler's  Operation  is  performed  with  his  knife,  which  has  a 
straight,  narrow  blade  7  mm.  long,  the  shank  just  fitting  the  puncture 
that  is  made.  It  is  introduced  at  the  upper  margin  of  the  cornea, 
carried  to  a  point  3  mm.  from  the  opposite  periphery  of  the  iris,  and 
3  mm.  from  the  lower  end  of  the  vertical  meridian.  The  membrane 
is  then  pierced  and  cut  upwards,  with  a  very  slight  sawing  motion. 
The  point  of  the  blade  is  then  carried  an  equal  distance  to  the 
other  side  of  the  vertical  meridian,  the  membrane  again  pierced 
and  cut  upwards  to  the  termination  of  the  first  incision.     The  flap 


CHAP.    X.] 


THE    CRYSTALLINE   LENS, 


293 


of  iridic  tissue  tlins  formed  retracts  downwards,  leaving  a  wide 
triangular  pupil. 

Discission  means  the  tearing  of  the  antei'ior  capsule  of  the 
lens  with  a  needle,  so  as  to  give  the  aqueous  humour  access  to  the 
lenticular  fibres,  which  causes  them  to  swell,  and  gradually  to 
become  disintegrated  and  absorbed.  The  larger  the  capsular  open- 
ing, the  more  freely  is  the  aqueous  brought  in  contact  with  the 
lens,  and  the  more  rapid  is  its  swelling.  The  rapidity  of  the  swelling, 
disintegration,  and  absorption  depend,  also,  on  the  original  con- 
sistence of  the  lens.  The  softer  it  is  the  more  rapid  is  the  process, 
the  completion  of  which  may  require  from  a  few  weeks  to  many 
months.  It  is  wise  to  make  the  first  discission  of  moderate  extent, 
especially  in  adults. 

The  instruments  required  are  a  spring  speculum,  a  fixation 
forceps,  and  a  discission  needle.  The  pupil  is  to  be  dilated  with 
atropine. 

The  eye  having  been  cocainised,  the  speculum  applied,  and  the 
eye  fixed  close  to  the  inner  margin  of  the  cornea,  the  needle  is  passed 
under  the  conjunctiva  a  few  millimetres  outside  the  margin  of  the 
cornea,  and  enters  the  anterior  chamber  sub-conjunctivally  at  the 
sclero-corneal  margin.  It  is  then  advanced  upwards  to  the  upper 
margin  of  the  pupil  (Fig.  106), 
where  it  is  passed  into  the 
capsule,  but  not  deeply  into 
the  lens,  and  a  vertical  incision 
is  effected  by  withdrawing  the 
instrument  slightly.  If  an  ex- 
tensive opening  in  the  capsule 
be  wished  for,  a  horizontal 
incision  can  be  added  to  the 
vertical  one  by  a  corresponding 
motion  of  the  needle.  During 
these  manoeuvres  the  sclero- 
cornea,  at  the  point  of  punc- 
ture, must  form  the   fulcrum 

for  thejnotions  of  the  instrument.  The  instrument  is  then  with- 
drawn from  the  eye,  and  some  aqueous  humour  escapes  through 
the  opening.  Atropine  is  instilled,  and  the  dressing  applied. 
The  patient  is  kept  in  bed  for  a  day,  and  then  the  dressing  may  be 


294  DISEASES   OF    THE   EYE.  [chap.  x. 

dispensed  with,  and  dark  spectacles  worn.  The  iris  is  to  be  kept 
well  under  the  influence  of  atropine,  until  the  absorption  of  the  lens 
is  completed.  Repetition  of  the  operation  is  called  for,  if  the  opening 
be  so  small  as  to  admit  of  but  a  very  slow  absorption  of  the  lens,  or 
if,  as  sometimes  happens,  the  opening  should  close. 

This  method  is  applicable  to  all  complete  cataracts  up  to  the 
twenty-fifth  year  of  age,  and  to  those  lamellar  cataracts  up  to  the 
same  age  in  which  the  opacity  approaches  so  close  to  the  periphery 
of  the  lens,  that  nothing  can  be  gained  by  an  iridectomy  (p.  270). 
After  the  above  age,  the  increasing  hardness  of  the  nucleus,  and  the 
increasing  irritability  of  the  iris,  render  the  method  unsuitable. 

Discission  is  a  safe  procedure,  when  used  with  the  above  indica- 
tions and  precautions.  Iritis  should  not  occur,  with  perfect  asepsis, 
indeed  it  is  much  more  liable  to  be  met  with  if  a  linear  extraction 
be  subsequently  done. 

Another  danger  consists  in  glaucomatous  increase  of  tension 
(secondary  glaucoma),  which  may  come  on  without  any  subjective 
symptoms — although  severe  pain  usually  attends  it — while  the 
absorption  of  the  lens  is  still  running  its  proper  course.  It  may 
happen,  consequently,  that,  when  absorption  of  the  cataract  is  com- 
pleted, the  eye  will  be  found  blind  from  glaucoma.  Frequent 
testings  of  the  tension  of  the  eye  during  the  cure  are  therefore  a"lnost 
important  precaution.  Should  the  tension  rise,  removal  of  the  lens 
through  a  linear  incision  in  the  cornea  is  at  once  indicated. 

Dislocation  of  the  Crystalline  Lens. — This  may  be  congenital 
(p.  294),  or  it  may  be  the  result  of  disease,  such,  for  example,  as 
anterior  sclero-chorioiditis  ;  or  it  may  be  caused  by  a  blow  on 
the  eye. 

The  dislocation  due  to  disease  or  trauma  may  be  partial  or 
complete.  Partial  dislocation  is  often  so  slight  as  to  be  discoverable 
only  when  the  pupil  is  widely  dilated,  the  margin  of  the  lens  becoming 
then  visible,  by  aid  of  the  ophthalmoscope  mirror,  as  a  curved  black 
line  in  some  one  direction  ;  or,  the  displacement  may  be  so  great 
as  to  bring  the  margin  of  the  lens  across  the  centre  of  the  undilated 
pupil,  in  which  case  one  part  of  the  eye  will  be  highly  hypermetropic, 
while  in  another  part  it  will  be  myopic.  Complete  dislocation  may 
take  place  into  the  anterior  chamber,  into  the  vitreous  humour,  or 
even  under  the  conjunctiva  (Fig.  69),  if  the  sclerotic  have  been 
ruptured. 


cHAr.  X.]  THE   CRYSTALLINE   LENS.  295 

The  symptoms  in  partial  dislocation  are  those  of  loss  of  power 
of  accommodation,  and  monocular  double  vision.  Iridodonesis  {i.e. 
trembling  of  the  iris  when  the  eye  moves)  is  present,  as  a  rule,  in 
consequence  of  the  loss  of  support  provided  for  the  iris  by  the  lens. 
The  anterior  chamber  is  caused  to  be  shallow  at  one  part  by  pressure 
of  the  dislocated  lens  against  it,  while  at  any  part  where  the  lens 
does  not  press  against  the  iris  it  is  deep.  In  complete  dislocation 
the  symptoms  are  those  of  aphakia — i.e.  extreme  hypermetropia, 
and  want  of  power  of  accommodation. 

Treatment. — In  partial  dislocation  it  is  rarely  that  any  treatment 
can  be  of  service.  The  prescribing  of  spectacles  suited,  so  far  as  it 
is  practicable,  to  the  faulty  refraction  is  indicated.  In  complete 
dislocation  of  the  lens  into  the  anterior  chamber,  its  extraction  is 
usually  required,  especially  if  it  cause  symptoms  of  irritation.  It 
is  advisable  to  fix  the  lens  with  a  discission  needle  before  extracting 
it  with  the  spoon,  otherwise  it  may  slip  back  out  of  sight.  Dis- 
location into  the  vitreous  humour  is  generally  unattended  by 
irritation  ;  but  when  the  latter  does  arise,  removal  of  the  lens  by 
aid  of  a  spoon,  through  a  peripheral  corneal  incision,  has  to  be 
attempted,  but  the  patient  should  be  warned  that  enucleation  may 
be  necessary  in  case  of  failure  to  remove  the  lens. 

Congenital  Defects  of  the  Lens.  Congenital  Cataract  (pp.  268,  209, 
271). 

Ectopia  of  the  Lens  (Congenital  Dislocation). — This  is  often  hereditary, 
and  often  present  in  more  than  one  member  of  a  family.  The  displace- 
ment is  more  frequently  in  an  upward  direction  than  in  any  other.  It 
is  usually  in  both  eyes.  It  is  due  to  a  mal-development  of  the  zonula  of 
Zinn,  which  in  these  cases  is  shorter  in  the  direction  towards  which  the 
lens  is  luxated.  Discission  or  extraction  is  not  indicated  here.  Occa- 
sionally some  advantage  is  gained  for  \asion  by  the  correction  with  glasses 
of  one  or  other  portion  of  the  doubly  refracting  eye. 

Coloboma  of  the  Lens. — Coloboma  of  the  lens  often  co-exists  with  colo- 
boma  of  the  iris  (p.  223),  but  may  be  present  alone.  It  is  generally  in 
the  lower  periphery  of  the  lens. 

Lenticonus. — This  is  a  rare  congenital  anomaly  of  the  lens,  in  which 
its  anterior  surface,  or,  still  more  rarely,  its  posterior  surface,  is  cone- 
shaped.  The  derangements  of  vision  are  very  smilar  to  those  caused  by 
conical  cornea. 

Aphakia  (a,  prk. ;  c^aKo'?,  a  lentiL  lens) ,  or  Absence  of  the  Crystal- 
line Lens. — The  emmetropic  eye  after  the  removal  of  a  cataract 
becomes  highly  hypermetropic,  and  its  power  of  accommodation  is 


296  DISEASES    OF    THE   EYE.  [chap.  x. 

lost.  Consequently,  in  order  that  the  eye  may  have  the  best  possible 
sight  for  distant  objects,  a  high  convex  glass  has  to  be  experimentally 
found  to  suit  it,  and  yet  stronger  lenses  must  be  prescribed  for 
shorter  distances. 

The  degree  of  vision  obtained  varies  considerably  in  different 
cases  ;  frequently  V  =  J  is  obtained,  but  V  =  y^  may  be  regarded 
as  a  satisfactory  result ;  and  even  lower  degrees,  which  enable  the 
patients  to  find  their  way  about  with  comfort,  are  classed  as  suc- 
cessful operations.  The  vision  often  improves  for  some  months 
after  the  operation,  patients  who  at  first  obtained  only  y^,  or  so, 
advancing  up  to  ^  or  J.  For  reading,  writing,  etc.,  at  about  25  cm., 
a  still  higher  convex  glass  must  be  provided.  If  the  correcting  lens 
for  distant  vision  be,  as  is  usually  the  case,  +  10  D,  its  power,  for 
the  purposes  of  vision  at  25  cm.,  must  be  increased  by  the  lens  which 
would  represent  the  amplitude  of  accommodation  from  infinite 
distance  up  to  25  cm.  This  lens  is  4  D  (because  VV-  =  4)  ;  therefore 
+  14  D  is  the  lens  required  for  reading,  etc.  With  these  two  lenses 
the  majority  of  cataract  patients  are  satisfied.  For  distinct  vision 
at  middle  distances,  they  learn  to  vary  the  power  of  the  lenses  by 
moving  them  a  little  closer  to,  or  farther  from,  the  eye  ;  but,  if 
necessary,  a  lens  can  be  prescribed  for  distinct  vision  at  any  desired 
distance. 

In  the  case  of  hospital  patients,  one  is  often  obliged  to  select  the 
+  glasses  a  -fortnight  or  three  weeks  after  the  operation,  but  the 
result  is  more  satisfactory  when  the  selection  can  be  postponed  for 
six  weeks  or  two  months.  Permanent  wearing  of  the  +  glasses 
should  not  be  permitted  until  all  redness  of  the  eye  has  passed  off, 
and  the  time  at  which  this  occurs  varies  in  different  cases.  Until 
then,  also,  dark  protection  spectacles  should  be  worn. 

In  the  majority  of  cases,  after  cataract  operations,  the  best 
vision  is  not  obtained  unless  a  certain  degree  of  astigmatism  is  cor- 
rected. This  astigmatism  is  caused  by  a  flattening  of  the  vertical 
meridian  of  the  cornea,  due  to  the  cicatrix  at  its  upper  margin,  and 
hence  it  is  against  the  rule  (chap,  xvi.),  so  that  the  axis  of  the  + 
cylinder  is  generally  parallel  to  the  incision.  An  obliquity  in  the 
incision  often  produces  an  obliquity  in  the  principal  meridians  of  the 
astigmatism.  The  degree  of  astigmatism  varies,  and  may  be  very 
high.  It  rapidly  reaches  its  maximum  after  the  operation,  and 
then  gradually  diminishes  for  weeks  or  months,  and  in  some  cases 


CHAP.  X.]  THE   CRYSTALLINE   LENS.  297 


completely  disappears  ;  hence  it  is  tliat  glasses  for  permanent  use 
can  be  better  prescribed  a  month  or  two  subsequently  to  the  opera- 
tion. We  have  found  that  corneal  incisions  give  rise  to  higher 
degrees  of  astigmatism  than  operations  with  a  conjunctival  flap. 

The  prismatic  action  of  strong  cataract  lenses  outside  the  central 
axis  interferes  with  clear  peripheral  vision,  and  this  has  been  to  a 
very  large  extent  obviated  by  lenses  invented  by  Gullstrand  with  a 
special  curvature.     They  are  called  "  aspherical  "  lenses. 


CHAPTER    XI. 

DISEASES   OF   THE   VITREOUS   HUMOUR. 

The  vitreous  humour  is  an  inert  body,  and  with  the  exception  of  some 
congenital  abnormalities,  the  diseases  affecting  it  are  mostly  secondary 
to  lesions  of  the  uveal  tract  or  retina. 

Purulent  Inflammation  of  the  Vitreous  Humour  occurs  only  as 
the  result  of  perforating  injuries,  or  of  the  lodgment  of  a  foreign  body, 
or  as  an  extension  of  a  purulent  process  from  the  chorioid  (p.  192). 

Ophthalmoscofically ,  a  purulent  deposit  in  the  vitreous  humour 
gives  a  yellowish  reflection,  when  light  is  thrown  into  the  eye  with 
the  ophthalmoscope  mirror,  or  on  examination  with  oblique  light. 

The  condition,  if  at  first  confined  to  the  vitreous  humour,  usually 
soon  extends  to  the  surrounding  tissues,  and  leads  to  panophthal- 
mitis (p.  192)  and  complete  destruction  of  the  eye. 

But,  in  some  cases  of  purulent  chorioiditis,  where  the  inflam- 
matory process  is  not  very  acute  or  violent,  there  may  be  little  or  no 
outward  signs  of  inflammation — there  may  be  no  iritis  or  irritation 
of  the  eye.  In  these  cases  difficulty  is  often  experienced  in  making 
a  diagnosis  between  abscess  of  the  vitreous  and  glioma  of  the 
retina,  in  w^hich  latter  disease,  too,  a  whitish  or  yellowish  reflex 
is  obtainable  from  the  vitreous  chamber.  These  cases  of  '  quiet ' 
purulent  infiltration  or  abscess  of  the  vitreous  humour  (so-called 
pseudo-glioma),  the  result  of  subacute  purulent  chorioiditis,  occur 
in  cerebro-spinal  meningitis,  the  acute  exanthemata,  with  foreign 
bodies  in  the  vitreous,  and  under  some  other  as  yet  obscure  con- 
ditions. Tubercle  of  the  chorioid  may  also  give  rise  to  the  appear- 
ance. The  history  of  the  case  and  low  tension  of  the  eye  in  abscess 
are  often  the  only  guides  in  diagnosis  ;  but  iritis,  or  posterior 
synechia,  and  retraction  of  the  periphery  of  the  iris,  with  bulging 
forwards  of  its  pupillary  part,  and  turbidity  of  tlie  vitreous,  if  these 
be  present,  speak  for  abscess,  while  a  lobulated  appearance  is  not 

298 


CHAP.  XI.]  THE    VITREOUS   HUMOUR,  299 

SO  common  as  in  glioma.  Occasionally,  however,  a  sure  diagnosis 
is  not  only  difficult,  but  impossible.  Yet  if  a  case  of  abscess  of  the 
vitreous  humour  be  taken  for  glioma  of  the  retina,  the  error  is  not 
practically  serious,  for  if  excision  of  the  eyeball  be  recommended 
for  a  case  of  abscess  it  will  be  done  on  an  eye  which  is  hopelessly 
blind,  and  which  would  become  phthisical  and  disfiguring.  The 
diagnosis  may  perhaps  be  assisted  by  means  of  transillumination 
(p.  218). 

Inflammatory  Affections  of  the  Vitreous  Humour,  other  than 
the  purulent  form,  are  for  the  most  part  the  consequence  of  diseases 
of  the  chorioid  (including  those  which  accompany  high  myopia, 
chap,  xvi.),  ciliary  body,  or  retina,  and  display  themselves  as  opa- 
cities of  various  kinds.  These  are  either  cells  derived  from  the 
primarily  diseased  tissue,  or  they  are  secondary  changes  (connective 
tissue  development)  in  the  vitreous  humour,  the  result  of  the  cellular 
invasion. 

The  chief  Varieties  of  Vitreous  Humour  Opacities  are  : — (1)  A 
Dust-like  Opacity  characteristic  of  syphilitic  disease  of  the  retina 
and  chorioid.  It  may  occupy  the  entire  vitreous  humour,  but  is 
frequently  confined  to  the  region  of  the  ciliary  body,  or  to  that  of 
the  posterior  layers  of  the  vitreous  humour.  (2)  Flakes  and  Threads. 
These  occur  with  chronic  affections  of  the  chorioid  or  ciliary  body, 
and  may  be  the  result  also  of  hsemorrhages  into  the  vitreous  humour. 
They  invade  every  portion  of  the  humour.  (3)  Membranous 
Opacities,  which  are  rare,  and  are  probably  the  result  either  of 
extensive  hsemorrhagic  extravasations  or  of  chorioidal  exudations. 

Most  of  the  alterations  in  the  vitreous  humour  are  attended  with, 
or  give  rise  to,  fluidity  of  it,  or  Synchysis.^ 

The  Diagnosis  of  opacities  in  the  vitreous  humour  is  made  with 
the  ophthalmoscope  mirror  and  a  not  very  bright  light,  or  with  the 
plane  mirror  (p.  35).  If  a  very  bright  light  and  a  concave  mirror 
be  employed,  the  finer  opacities  will  not  be  readily  seen.  The  pupil 
being  illuminated,  the  patient  is  directed  to  look  rapidly  in  different 
directions,  when  the  opacities  will  be  seen  to  float  across  the  area 
of  the  pupil,  as  they  are  thrown  from  one  side  of  the  eye  to  the 
other  in  the  fluid  vitreous. 

Opacities  in  the  vitreous  can  be  distinguished  from  those  in  the 


■■   rriV,  together  ;  \eo},   to  pour. 


300  DISEASES   OF    THE   EYE.  [chap.  xi. 

lens  by  the  fact  tliat  the  latter  are  fixed,  and  are  arranged  for  the 
most  part  in  a  radiating  manner. 

Another  and  very  fine  method  for  the  detection  of  delicate 
opacities  in  the  vitreous  consists  in  placing  a  high  +  lens,  say  +  10  D, 
behind  the  ophthalmoscope  mirror,  and  then  approaching  close  to 
the  eye,  as  in  the  examination  of  the  upright  image.  Minute  opaci- 
ties will  then  be  seen  as  black  dots  floating  in  the  vitreous  humour. 

The  ophthalmoscope  does  not  always  detect  changes  in  the 
chorioid  or  retina,  when  opacities  are  present  in  the  vitreous  ;  and 
in  many  such  cases  we  are  led  to  the  belief,  either  that  the  diseased 
changes  in  the  chorioid  or  retina  are  too  fine  to  be  seen  with  the 
ophthalmoscope,  or  that  they  are  situated  in  the  region  of  the 
ciliary  body  which  is  out  of  view. 

When  the  optic  disc  is  viewed  through  a  vitreous  humour  full 
of  fine  opacities,  it  appears  redder  than  the  normal,  as  does  the 
sun  on  a  foggy  day,  and  it  may  be  difficult  to  decide  whether  or 
not  neuritis  is  present. 

Vision  is  affected  by  opacities  in  the  vitreous  humour  in  pro- 
portion to  their  density,  and  to  the  extent  to  which  the  vitreous 
humour  is  occupied  by  them.  The  patients  often  observe  them  as 
floating  positive  scotomata  in  their  field  of  vision.  These  entoptic 
appearances  are  caused  by  the  shadows  of  the  opacities  thrown,  on 
the  retina. 

The  Prognosis  depends  on  the  cause  of  the  opacities.  The  dust- 
like opacities  accompanying  specific  retinitis  are  favourable  for 
absorption,  while  the  flake  and  thread  opacities  frequently  remain 
as  permanent  obstructions.  Moreover,  by  shrinking,  many  of  the 
more  organised  opacities  give  rise  to  detachment  of  the  retina  and 
consequent  blindness. 

Treatment. — Opacities  of  the  vitreous  humour  offer  special  diffi- 
culties in  their  treatment  owing  to  the  torpid  metabolism  of  the 
part,  and  the  consequent  difficulty  in  influencing  its  tissues  by  in- 
ternal remedies.  In  addition  to  the  medicines  suitable  for  the  con- 
stitutional state  which  may  be  the  cause  of  the  opacities,  Heurte- 
loup's  artificial  leech,  or  dry  cupping  on  the  temple,  is  useful ;  and 
in  many  cases,  soon  after  the  application,  a  marked  clearing  up  of 
the  vitreous  is  apparent. 

Sub-conjunctival  injections  (p.  120)  of  a  4  per  cent,  sterilised 
solution  of  chloride  of  sodium  are  a  valuable  treatment  for  opacities 


CHAP.  XL]  THE    VITREOUS  HUMOUR.  301 

in  the  vitreous  liumour,  in  many  chronic  or  subacute  cases.  They 
are  not  used  if  acute  uveitis  be  present.  The  injection  is  repeated 
after  a  day  or  two,  when  the  swelHng  and  irritation  have  subsided. 
Usually  not  more  than  two  or  three  injections  can  be  oiven  in  a 
week. 

Sub-conjunctival  injections  enter  largely,  also,  into  the  therapy 
of  chronic  uveal  diseases  (p.  187,  etc.),  of  certain  corneal  diseases 
(p.  120,  etc.),  and  of  some  other  diseases  of  the  eye  (p.  287). 

The  curative  action  of  these  injections  depends  on  the  hyper- 
cTmia  to  which  they  give  rise,  and  the  consequent  increased  supply 
to  the  diseased  part  of  the  healing  substances  of  the  blood — the 
opsonins,  bacteriolysins,  etc.  There  is  consequently  little  to  be 
gained  therapeutically  in  non- purulent  cases  by  the  use  of  solutions 
of  sublimate,  cyanide  of  mercury,  hetol,  and  so  on,  in  preference  to 
the  4  per  cent,  solution  of  common  salt. 

Haemorrhage  in  the  Vitreous  Humour.— This  is  often  caused 
by  blows  on  the  eye,  which  rupture  intra-ocular  blood-vessels.  It 
is  the  result,  too,  of  certain  diseases  of  the  retina  and  chorioid,  which 
are  accompanied  by  haemorrhages  in  those  membranes  ;  or,  of 
disease  of  the  coats  of  the  retinal  or  chorioidal  vessels.  It  is  seen 
in  old  people  with  atheromatous  vessels,  and  it  occurs  in  pernicious 
anaemia,  syphilis,  and  malaria. 

Some  quite  healthy  young  people  of  both  sexes  are  liable  to 
recurrent  hsemorrhages  in  the  vitreous  humour,  which,  when  they 
cease,  either  leave  the  vitreous  humour  clear,  or  it  may  remain  more 
or  less  opaque.  Strands  of  connective  may  form  in  it,  or  it  may 
be  followed  by  retinitis  proliferans,  or  by  detachment  of  the 
retina.  In  most  cases  no  satisfactory  explanation  for  the  occur- 
rence of  these  haemorrhages  in  young  people  can  be  offered,  but  in 
some,  early  arterio-sclerosis  or  tubercular  disease  of  the  coats  of  the 
retinal  or  chorioidal  blood-vessels  may  be  the  cause.  The  arterial 
tension  is  often  high,  constipation  is  often  present,  and  there  may 
be  epistaxis. 

Haemorrhages  in  the  vitreous  humour,  when  viewed  with  the 
ophthalmoscope,  present  the  appearance  of  black  floating  masses, 
between  which  the  chorioidal  reflex  appears.  If  they  lie  in  the 
anterior  part  of  the  vitreous  chamber,  close  behind  the  lens,  they 
may  be  seen  with  focal  illumination,  and  then  are  red.  When 
the  vitreous  humour  is  full  of  blood,  no  red  reflex  can  be  obtained 


302  DISEASES   OF    THE   EYE.  [chap.  xi. 


with  the  ophthalmoscope,  and  the  pupil  looks  quite  black  when 
light  is  thrown  into  the  eye  from  the  mirror. 

Treatment. — The  constitutional  cause,  if  discoverable,  should  be 
treated.  Sub-conjunctival  saline  injections  will  promote  absorption 
of  vitreous  humour  hremorrhages,  and  the  internal  administration  of 
citric  acid  has  been  recommended  on  the  ground  that  an  increased 
coagulability  of  the  blood  is  present.  If  the  coagulability  of  the 
l)lood  be  reduced,  lactic  acid  or  calcium  chloride  is  indicated. 
Fibrolysin  has  been  employed  in  these  cases  apparently  with  ad- 
vantage in  some  of  them.  But  many  of  these  cases  are  incur- 
able, or  undergo  only  partial  cure.  In  recent  cases  rest  in  bed  is 
important. 

Mouches  Volantes,  Muscse  Volitantes,  and  Myodesopsia  ^  are 
terms  applied  to  the  motes  which  people  frequently  see  floating 
before  their  eyes,  but  which  do  not  interfere  with  the  acuteness  of 
vision,  nor  can  the  ophthalmoscope  detect  opacities  in  the  vitreous 
humour,  nor  any  other  intra-ocular  disease.  These  motes  are  most 
apparent  when  a  bright  surface,  such  as  a  white  wall  or  the  field  of  a 
microscope,  is  looked  at.  Mouches  volantes  have  no  clinical  im- 
portance. Those  annoyed  with  them  should  be  strongly  recom- 
mended not  to  look  for  them,  as  in  that  case  others  are  very  apt  to 
become  visible.  They  depend,  probably,  upon  minute  remains  of 
the  embryonic  tissues  in  the  vitreous  humour. 

Fluidity  of  the  Vitreous  Humour,  or  Synchysis,  is  not  rare. 
It  can  only  be  diagnosed  with  certainty  when  the  humour  contains 
floating  opacities.  Low  tension  of  the  eyeball  does  not  always 
indicate  fluidity  of  the  vitreous,  although  soft  eyeballs  nearly  always 
contain  fluid  vitreous  humour.  Trembling  of  the  iris  (iridodonesis) 
is  also  no  sign  of  fluid  vitreous,  although  it  often  accompanies  it, 
but  merely  indicates  that  the  iris  is  not  supported  in  the  normal 
way  by  the  crystalline  lens.  Defective  zonula  of  Zinn,  however,  is 
often  caused  by,  or  is  a  concomitant  of,  fluid  vitreous  ;  and,  by 
causing  displacement  of  the  lens,  would  allow  of  trembling  of  the  iris. 

The  causes  of  synchysis  are  chorioiditis  and  staphyloma  of  the 
chorioid  and  sclerotic,  and  it  also  occurs  as  a  senile  change. 

Fluidity  of  the  vitreous  humour  is  not,  j)er  se,  a  condition  of 
serious  import,  unless  the  eye  come  to  be  the  subject  of  an  operation 

^  fxv'ia,  a  fly  ;  bfis,  seeing. 


CHAP.  XT.]  THE    VITREOUS   HUMOUR.  303 

involving  an  incision  in  the  corneo-sclerotic  coat,  when  it  renders 
prolapse  of  the  vitreous  more  liable  to  take  place. 

Synchysis  Scintillans  is  a  fluid  condition  of  the  vitreous  humour, 
with  cholesterine  and  tyrosine  crystals  held  in  suspension  in  it. 
The  ophthalmoscopic  appearances  are  very  beautiful,  resembling 
a  shower  of  golden  rain.  They  usually  occur  in  old  people,  and 
seldom  cause  any  marked  deterioration  of  vision. 

Foreign  Bodies  in  the  Vitreous  Humour  and  Interior  of  the 
Eye  in  General. — One  of  the  most  common  and  most  serious  acci- 
dents to  the  eye  is  perforation  of  the  sclerotic,  or  of  the  cornea  and 
crystalline  lens,  by  a  small  foreign  body  (shot,  morsel  of  iron,  copper, 
stone,  or  glass),  which  lodges  in  some  part  of  the  interior  of  the  eye 
— very  frequently  in  the  vitreous  humour. 

The  danger  threatened  by  a  foreign  body  in  the  eye  is  great. 
It  is  rarely  that,  whether  it  remain  free,  or,  as  sometimes  happens, 
become  encapsuled,  it  is  tolerated  permanently  in  any  part  of  the 
interior  of  the  eye  without  inflammatory  reaction,  except  when  it 
lies  in  the  crystalline  lens,  and  there,  as  a  rule,  it  causes  cataract. 
Freedom  from  inflammatory  reaction  should  never  be  reckoned 
on  in  the  management  of  such  a  case. 

As  a  rule,  foreign  bodies  in  the  vitreous,  or  elsewhere  within  the 
eye,  soon  produce  violent  inflammatory  reaction.  This  occurs, 
either  by  reason  of  infective  micro-organisms  being  introduced  into 
the  eye  with  the  foreign  body,  or,  it  may  be  caused  by  the  oxidisation 
of  the  foreign  body,  when  it  is  of  iron  or  copper.  The  form  of  in- 
flammation may  be  either  a  plastic  or  a  purulent  uveitis,  in  the 
latter  case  with  purulent  infiltration  of  the  vitreous  humour  and 
hypopyon. 

Foreign  bodies  of  copper  are  more  likely  to  cause  purulent 
inflammation  than  those  of  any  other  kind. 

Should  a  foreign  body  of  iron  or  steel  remain  in  the  eye  long 
enough — months  or  years — without  giving  rise  to  inflammatory 
reaction,  it  is  apt  to  cause  siderosis,  or  rusting,  of  all  the  tissues  of 
the  eyeball,  the  iris  becoming  of  a  reddish  brown  hue.  Cyclitis 
and  intra-ocular  haemorrhage  follow,  accompanied  by  much  pain, 
vision  is  lost,  and  the  eye  has  to  be  excised. 

Consequently,  when  an  eye  contains  a  foreign  body  that  is  not, 
or  cannot  be,  at  once  removed,  the  eye  may  be  regarded  as  lost. 
Moreover,  such  an  eye  becomes  one  of  the  surest  sources  of  sym- 


304  DISEASES   OF    THE   EYE.  [chap.  xi. 

pathetic  ophthalmitis,  when  it  is  plastic  and  not  purulent  inflam- 
mation tluit  is  set  up  in  it. 

As  soon  as  the  case  is  seen,  the  first  question  to  be  asked  of 
the  patient  is  :  What  was  the  size  of  the  foreign  body  ?  A  minute 
foreign  body,  especially  if  it  fly  against  the  eye  with  force,  is  likely 
to  perforate  the  walls  of  the  eyeball  and  to  lodge  in  its  interior  ; 
while  a  large  foreign  body  may  cause  a  perforating  wound,  but 
may  then  fall  to  the  ground.  The  second  question  to  be  asked  is  : 
What  was  the  foreign  body  made  of  ? 

It  is,  therefore,  of  the  utmost  importance  to  decide  whether  or 
not  a  foreign  body  be  in  the  eye  ;  and  if  one  be  there,  to  remove 
it  if  possible,  should  a  reasonable  prospect  of  saving  even  partial 
sight  exist ;  and  this,  too,  without  delay.  When  the  foreign  body 
cannot  be  removed,  the  eyeball  must  be  excised. 

Means  of  deciding  objectively  ivhether  a  Foreign  Body  he  in  the 
Fyc. — If  the  case  be  seen  immediately,  or  soon  after  the  accident, 
and  there  be  no  intra-ocular  haemorrhage  to  obscure  the  view,  the 
foreign  body  may  perhaps  be  detected  with  the  ophthalmoscope 
in  the  vitreous  humour  or  fundus  oculi  as  a  dark  or  glittering  body, 
according  to  its  nature  ;  and  focal  illumination  with  dilated  pupil 
will  often  help  the  surgeon  to  discover  a  foreign  body  situated 
in  the  anterior  part  of  the  vitreous  humour.  Or,  if  it  cannot  be 
seen,  an  opaque  streak  through  the  vitreous  humour,  one  end  of 
which  corresponds  with  the  sclerotic  wound,  may  indicate  the 
track  taken  by  a  foreign  body. 

In  case  the  foreign  body  have  perforated  the  cornea,  and  reached 
the  vitreous  humour  through  the  circumlental  space,  a  counter- 
opening  will  be  found  in  the  iris  ;  while,  if  it  be  supposed  to  have 
passed  through  the  cornea  and  lens,  the  openings  both  in  the  anterior 
and  posterior  capsule  of  the  lens  should  be  sought  for. 

In  cases  where  the  ophthalmoscope  and  focal  illumination  fail 
us,  owing  to  extravasation  of  blood,  traumatic  cataract,  etc.,  it 
is  sometimes  not  easy  to  say  whether  the  foreign  body  be  in  the 
eye,  or  whether  it  may  have  merely  punctured  the  sclerotic,  or 
cornea,  and  then  fallen  to  the  ground,  without  passing  into  the  eye. 

The  Rontgen  Rays  must  then  be  resorted  to,  should  the  foreign 
body  be  of  any  metal  or  of  glass,  to  decide  both  upon  its  presence 
and  position,  and  the  Sideroscope  is  useful  for  the  same  purposes, 
but  only  if  the  object  be  of  iron  or  steel. 


CHAP.    XI.] 


THE    VITREOUS   HUMOUR. 


305 


The  following  is  Mackenzie  Davidson's  method  for  employing  the 
Rontgen  Rays  in  these  cases  : — 

The  patient  sits  upon  a  chair  in  an  upright  position,  with  his  head 
fixed  in  a  headpiece  (clamped  to  a  table)  to  keep  it  steady  (Fig.  107),  while 
at  the  same  time  a  photographic  dry  plate  can  be  placed  against  the 
temple  on  the  side  of  the  eye  which  is  to  be  photographed. 

Fig.  108  is  a  picture  of  a  patient's  head  in  position  for  taking  the  right 
eye.  The  back  of  the  head  rests  against  a  board,  and  another  board,  with 
a  thumb-screw  sliding  in  a  groove,  serves  to  press  and  fix  his  head  laterally 
against  two  stretched  piano-wires,  behind  which  again  the  photographic 
plate  is  placed.     The  chin  is  supported  on  an  adjustable  projection. 

Fig.  109  is  a  side  view  of  the  same  patient.  The  stretched  piano-wires 
are  shown.  The  patient,  while  the  skiagram  is  being  taken,  is  made  to 
fix  his  gaze  on  a  distant  object,  so  that  his  optic  axis  is  parallel  to  the 


Fig.   107. 


horizontal  wire.  Previously,  a  small  piece  of  lead  wire,  exactly.  1  cm. 
long,  is  placed  on  the  lower  eyelid,  and  secured  by  two  strips  of  adhesive 
plaster,  and  the  relative  position  of  the  point  of  the  wire  (nearest  the  eye) 
is  carefully  noted  in  relation  to  the  cornea  {e.g.  so  many  millimetres 
vertically  below  the  centre  of  the  cornea,  or  so  many  millimetres  vertically 
below  any  corneal  scar  which  may  happen  to  be  present)  ;  also  whether 
the  point  is  on  a  level  with  a  vertical  line  from  the  centre  of  the  cornea 
(as  it  usually  is),  or  how  far  behind  or  in  front  of  this  plane.  These  are 
all  the  adjustments  necessary  to  be  made  w^ith  the  patient. 

Before  the  patient  is  placed  in  position,  the  Crookes  tube  is  adjusted, 
so  that  the  fine  point  on  the  anode,  from  which  the  linear  rays  originate, 
shall  be  exactly  opposite  the  point  of  intersection  of  the  two  stretched 
piano-wires.  When  the  tube  is  worked  by  the  coil,  this  point  shows  as 
a  bright  incandescent  spot  on  the  anode,  if  it  be  of  osmium  ;  and  by  means 
of  a  fixed  '  sight,'  placed  on  this  side  of  the  wires,  the  tube  can  be  so 
adjusted  that  this  point  is  exactly  opposite  the  intersection  of  the  wires. 
The  distance  is  carefully  noted  :  it  is  usually  28  to  30  cm.  The  tube- 
holder  is  fixed  to  a  bar  of  wood,  which  slides  horizontally,  and  by  means 
of  marks  placed  on  the  bar  itself,  and  upon  the  edge   of  the  groove  in 

20 


30  ft 


DISEASES   OF    THE   EYE. 


[chap.    XT. 


which  it  sHdes,  it  can  be  displaced  in  a  plane  exactly  parallel  to  the  hori- 
zontal wire.  It  is  to  be  displaced  3  cm.  to  one  side  of  the  vertical  or  zero 
point.  Then  a  photographic  plate,  protected,  as  usual,  in  black  paper, 
is  placed  against  the  wires  (Fig.  109),  and  an  exposure  given  of  from  ninety 
seconds  to  two  minutes.  With  exceptionally  good  osmium  tubes  ten 
seconds  is  enough.  The  tube  is  then  displaced  3  -cm,  to  the  other  side  of 
the  zero  point — the  photographic  plate  having  been  removed  and  a  fresh 
one  put  in  its  place— and  a  second  similar  exposure  is  given.  The  result 
is  two  negatives  taken  from  two  points  of  view  0  cm.  apart. 

A  transparent  sheet  of  thin  celluloid  has  two  cross  lines  marked  upon 
it  at  right  angles  to  each  other.  One  side  is  varnished,  so  that  it  will 
readily  take  pencil  marks.     Immediately  after  development   and  fixing, 


1 

11^       ^      Ml        i        ■ 

Fig.   108. 


this  sheet  of  celluloid  is  placed  over  the  film  side  of  the  negative,  so  that 
its  two  lines  are  exactly  superimposed  upon  the  white  lines  left  by  the 
wires  in  the  headpiece  ;  while  firmly  held  in  position,  the  shadow  of  the 
leaden  wire  or  landmark,  placed  on  the  lower  eyelid,  is  carefully  traced. 
Then  the  foreign  body  is  traced  in  the  same  way.  This  process  of  tracing 
is  repeated  with  the  other  negative.  The  result  is  that  upon  the  sheet 
of  celluloid  two  tracings  of  the  leaden  landmark  wire,  and  two  tracings 
of  the  foreign  body,  side  by  side,  are  obtained. 

This  celluloid  tracing  is  now  placed  upon  the  horizontal  glass  stage  of 
the  Cross-Thread  Localiser.  The  latter  has  two  fine  silk  threads  coming 
from  two  points,  which  are  so  adjusted  as  to  occupy  relatively  the  two 
positions  occupied  by  the  anode  of  the  Crookes  tube,  and  to  be  at  the 
same  distance  from  the  celluloid  tracing,  and  also  in  the  same  relative 
position  to  the  cross-lines,  that  the  anode  of  the  Crookes  tube  had  to  the 
photographic  plate  and  to  the  cross-wires  of  the  headpiece,  when  the  photo 
graphs  were  being  taken. 

The  silk  threads  are  now  used  to  trace  the  linear  paths  of  the  rays. 
The  intersection  of  the  two  threads  fixes  the  position  of  the  object  in  space. 


CHAr.    XT.] 


THE    VITREOUS   HUMOUR. 


307 


Its  geometrical  relations  to  the  known  data  can  then  be  measured.  First, 
the  three  co-ordinates  of  the  known  point  are  ascertained,  then  the  three- 
co-ordinates  of  the  unknown  foreign  body,  and  then,  by  simple  subtrac- 
tion, the  minor  co-ordinates  are  obtained,  and  thus  the  position  of  the 
foreign  body  is  accurately  determined.  The  observer  is  enabled  to  say 
liow  far  horizontally  inwards  or  outwards  the  foreign  body  lies  from  the 
point  of  the  landmark  lead  wire  ;  from  that  point  how  far  vertically 
upwards  or  downwards  it  lies  ;  and  finally,  how  far  directly  backwards, 
parallel  to  the  visual  axis,  it  is  situated.  If  care  be  taken,  the  position 
of  a  foreign  body,  however  small,  can  be  ascertained  with  great  accuracy 
by  this  method.  Its  size  also  can  be  discovered.  Moreover,  the  two 
negatives  are  stereoscopic,  so  that,  when  viewed  either  in  a  Wheatstone's 


FiCx.   109. 


reflecting  stereoscope,  or  by  converging  the  optic  axes,  and  so  fusing  the 
pictures,  a  single  picture  in  relief  is  seen,  showing  the  relative  position  of 
the  parts  in  a  very  beautiful  manner. 

The  Sideroscope  is  used  for  the  detection  of  the  presence  of  particles  of 
steel  or  iron  in  the  eye.  It  consists  in  a  magnetic  needle  hung  by  a  fine 
thread,  and  so  mounted  that  when  it  is  brought  close  to  the  eye  containing 
the  foreign  body,  its  deflections  can  be  read  by  means  of  an  astronomical 
telescope  which  is  attached.  The  sideroscope  is  vised,  too,  for  ascertaining 
the  position  of  the  foreign  body,  which  is  nearest  to  the  part  where  the 
deflection  of  the  needle  is  greatest.  This,  of  course,  is  only  an  approxi- 
mate localisation,  and  the  method  is  not  much  employed  in  these  countries, 
as  the  Rontgen  Ray  method  fulfils  the  requirements  more  completely. 

When  it  has  been  decided  that  a  foreign  body  is  in  the  eye,  and  when 
its  position  has  been  determined,  its  removal  must  be  attempted. 


308  DISEASES   OF   THE   EYE.  [chap.  xi. 

Removal  of  a  Foreign  Bodij  from  within  the  Eye. — The  facility 
with  which  foreign  bodies  can  be  removed  from  the  eye  will  depend 
upon  their  position,  upon  the  length  of  time  they  have  been  in  the 
eye,  and  upon  whether  they  be  magnetic  or  not. 

A.  Magnetisable  Foreign  Bodies.  The  removal  of  particles  of  iron 
or  steel  is  more  often  successful  than  if  the  foreign  body  be  of  some 
other  substance  ;  for,  in  these  cases,  the  magnet  renders  valuable 
aid,  and  makes  it  unnecessary  that  the  foreign  bodies  should  be 
visible,  if  they  have  been  localised  by  the  Rontgen  Eays.  And 
even  localisation  with  the  Rays  may  be  foregone,  where,  in  a  quite 
recent  case,  it  is  important  there  should  be  no  delay  in  removing 
the  foreign  body. 

There  are  two  kinds  of  magnets,  the  small  or  hand  magnet,  and 
the  large  or  giant  magnet,  and  the  methods  of  using  them  are 
essentially  different.  The  small  magnet  can  only  attract  bodies  a 
few  millimetres  away,  and  it  is  almost  always  necessary  to  introduce 
the  magnet  point  into  the  eye,  thereby  increasing  the  risk  of  sepsis, 
and  of  injury,  whereas  with  the  large  instrument  the  foreign  body 
can  be  withdrawn  from  the  deeper  parts  of  the  eyeball  without 
bringing  the  magnet  into  contact  with  the  eye. 

Fig.  110  represents  one  of  the  small  electro-magnets  (Snell's)  in 
two-thirds  its  actual  size.  It  is  a  core  of  soft  iron,  around  which  is 
placed  a  coil  of  insulated  copper  wire,  the  w^hole  enclosed  in  an  ebonite 
case.  To  one  extremity  of  the  instrument  are  attached  the  screws 
to  receive  the  connections  of  a  small  accumulator.  At  the  other 
extremity  the  core  projects  just  beyond  the  ebonite  jacket,  and  is 


Fio.    110. 


tapped,  and  into  it  the  point  is  screwed.  Points  of  various  kinds  or 
shapes  can  be  adjusted  to  the  magnet,  according  to  the  case  to  be 
dealt  with.  A  sterilised  point  adjusted  to  the  magnet  having  been 
passed  throu<ih  the  sclerotic  opening,  it  is  advanced  towards  the 


CHAP,    xr.] 


THE    VITREOUS   HUMOUR. 


309 


foreign  body,  wlien  the  latter  adheres  to  it,  and  is  withdrawn  towards 
the  wound.  Much  care  is  required  in  drawing  the  foreign  body 
through  the  opening,  lest  it  be  rubbed  of!  the  point  in  its  passage. 
A  forceps  is  generally  used  at  this  part  of  the  proceeding,  either  to 
dilate  the  wound,  or  to  seize  the  foreign  body  and  extract  it.  As 
short  and  as  large  a  point  as  is  consistent  with  the  particular  case 
should  be  employed,  so  that  the  greatest  possible  power  of  attraction 
may  be  obtained.  A  quart  bichro- 
mate battery,  or  the  street  current, 
is  used.  When  the  foreign  body 
is  embedded  in  the  coats  of  the 
eye  at  the  back,  or  in  a  mass  of  in- 
flammatorv  effusion,  or  is  entangled 
in  the  ciliary  region,  difficulty  or 
failure  in  the  extraction  is  likely  to 
be  experienced.  When  a  trau- 
matic cataract  is  present,  it  is  well 
to  combine  its  extraction  with  that 
of  the  foreign  body,  which  latter  is 
fetched  out  tlirough  the  cataract 
incision  with  the  magnet. 

Haab's  Giant  Electro-Magnet  is 
represented  in  Fig.  111.  It  is  an 
immense  and  very  powerful  magnet, 
to  which  the  eye  is  brought  close 
Care  is  required  in  its  use,  lest  even 
more  injury  be  done  to  the  delicate 
tissues  of  the  eyeball  by  the  foreign 
body  in  its  passage  towards  the 
magnet,  than  by  its  entrance  into 
the  eye.  As  a  rule,  it  is  recom- 
mended that  the  centre  of  the 
cornea,  in  the  first  instance,  be 
brought  opposite  and  close  to  the  point  of  the  magnet ;  for,  by  so 
doing,  entanglement  of  the  foreign  body  in  the  ciliary  processes, 
from  which  it  is  not  easy  again  to  disengage  it,  may  best  be  avoided. 
Foreign  bodies  which  are  in  the  vitreous  humour,  or  which  are  not 
too  firmly  fixed  in  the  retina,  slide  round  the  lens  and  bulge  the 
iris  forwards.     As  soon  as  this  occurs  the  current  is  switched  off 


Fig.    111. — Haab's  Giant 
Electro-Magnet. 


310 


DISEASES   OF    THE   EYE. 


[chap.   XI. 


by  depressing  the  pedal  with  the  foot,  and  the  patient's  head  with- 
drawn from  the  maj^net.  The  patient  usually  feels  a  sensation  of 
pain  and  draws  his  head  back  involuntarily,  and  Haab  claims  that 
this  is  one  of  the  advantages  of  his  method  of  procedure,  inasmuch 
as  the  patient  by  this  movement  prevents  the  lodgment  of  the  foreign 
body  in  the  ciliary  region  or  iris.  When  it  has  advanced  behind  the 
iris,  the  patient  is  requested  to  rotate  the  eye  towards  the  side  where 
the  particle  lies,  so  that  the  magnet,  when  the  current  is  again 
switched  on,  will  exert  a  vertical  or  lateral  pull,  as  the  case  may  be, 
and  draw  the  particle  into  the  anterior  chamber  (Fig.  112)  through 
the  pupil,  which  has  been  well  dilated  with 
atropine  and  cocaine.  Should  it  not  be 
possible  to  get  the  foreign  body  away  from 
behind  the  periphery  of  the  iris  with  the 
magnet,  an  iridodialysis  may  be  formed  with 
a  keratome,  and  the  foreign  body  drawn 
away  with  a  Snell's  magnet  or  with  a  forceps. 
One  should  not  attempt  to  draw  the  foreign 
body  by  the  magnet  through  the  iris,  or  else 
the  latter  may  be  partially  or  entirely  pulled 
away.  Having  got  the  foreign  body  into  the 
anterior  chamber  through  the  pupil,  an  in- 
cision with  a  Grsefe's  knife  is  made  in  the 
cornea,  if  possible  without  allowing  the 
aqueous  humour  to  flow  away,  and  the  in- 
cision is  brought  opposite  to  the  tip  of  the  giant  magnet  and 
lightly  pressed  against  it.  If  much  aqueous  be  lost,  it  is  necessary 
to  wait  until  it  collects  again,  or  the  point  of  the  small  hand 
magnet  is  introduced  into  the  anterior  chamber.  Even  foreign 
bodies  which  enter  through  the  sclerotic  are  best  removed  through 
the  anterior  chamber.  When  the  foreign  body  is  firmly  fixed,  it 
may  often  be  loosened  by  switching  the  current  rapidly  on  and  off, 
or  it  may  first  be  drawn  towards  the  equator,  and  then  towards  the 
anterior  chamber. 

Haab  recommends  that  no  time  should  be  lost  in  removing  a 
foreign  body,  and  for  this  reason  he  applies  the  magnet  even  before 
attempting  to  localise  the  foreign  body  by  the  X-rays  or  sideroscope. 
The  occurrence  of  pain  in  the  eye  when  the  magnet  is  used  is  in 
itself  diagnostic  of  the  presence  of  a  foreign  body. 


Fig.  112.— The 
numbers  1  and  2  in- 
dicate the  first  and 
second  positions  of 
the  magnet  and  the 
corresponding  move- 
ment of  the  foreign 
body. 


CHAP,  xi.l  THE    VITREOUS   HUMOUR.  '311 


It  should  be  remembered  that  some  varieties  of  iron  amalgams, 
e.g.  those  containing  chromium  or  aluminium,  become  non-magnetic, 
also  that  shot  sometimes  is  made  with  iron  and  is  then  magnetisable. 

B.  Non-Magnetisable  Foreign  Bodies.  If  the  foreign  body  be  of 
some  substance  other  than  iron  or  steel — glass,  copper,  stone,  etc. — 
it  may  sometimes  be  removed  through  an  incision  in  the  sclerotic, 
which  is  either  an  enlargement  of  the  opening  made  by  the  foreign 
body,  or  is  a  special  one,  at  a  point  more  nearly  corresponding  with 
the  actual  position  of  the  foreign  body  in  the  eye.  In  a  few  cases 
the  foreign  body  can  be  kept  in  view  with  the  ophthalmoscope 
while  it  is  being  seized  and  drawn  out.  The  incision  should  lie 
between  two  recti  muscles,  should  have  an  antero-posterior  direc- 
tion, and,  in  order  that  it  may  gape  but  little,  should  be  a 
puncture  with  a  broad  keratome.  Prolapse  of  the  vitreous  is 
then  produced  by  pressure  on  the  eyeball,  and  the  foreign  body  is 
evacuated. 

This  method  may  be  employed  only  when  the  foreign  body 
is  situated  in  the  periphery  of  the  vitreous,  and  towards  the  equator 
of  the  eye,  where  the  opening  for  its  exit  can  be  made  in  its  immediate 
neighbourhood  ;  but  the  proceeding  is  often  attended  with  dis- 
appointment, much  vitreous  being  lost,  while  the  foreign  body 
remains  in  the  eye. 

In  Sach's  procedure,  which  is  a  good  one,  the  operation  is  per- 
formed under  general  anaesthesia  in  a  darkened  room,  and  the 
interior  of  the  eye  is  lighted  up  by  transillumination  with  a  special 
transilluminator,  through  the  cornea  or  sclera.  The  lips  of  the 
wound  are  held  apart  with  small  retractors,  and  it  may  then  be 
possible  to  see  the  foreign  body  through  the  wound. 

It  is  sometimes  preferable  to  make  the  opening  not  close  to  the 
foreign  body,  but  exactly  at  the  opposite  side  of  the  eyeball,  by 
which  means  the  foreign  body  can  often  be  reached  with  greater 
ease,  and  with  less  injury  to  the  tissues. 

One  should  not  be  too  sanguine  of  the  ultimate  result  in  cases 
even  of  successful  removal  of  a  foreign  body  by  means  of  the  magnet 
or  otherwise,  as  later  on  degenerative  changes  sometimes  spoil  what 
at  first  promised  to  be  a  brilliant  result. 

Cysticercus  in  the  Vitreous  Humour  was  not,  until  late  years, 
very  rare  in  some  parts  of  Germany,  but  there  have  not  been  many 
cases  observed  in  the  British  Isles.     We  have  seen  one  case  of 


312  DISEASES    OF    THE   EYE,  [chap.  xi. 

cysticercus  in  Ireland  and  also  a  much  rarer  parasite,  so  far  as  the 
eye  is  concerned,  namely  the  echinococcus. 

The  original  seat  of  the  cysticercus  is  usually  beneath  the  retina 
(chap,  xii.),  through  which  it  breaks  to  reach  the  vitreous  humour; 
but  it  also  sometimes  makes  its  first  appearance  in  the  vitreous.  It 
is  recognised  by  its  peculiar  somewhatdumb-bellshape, its  iridescence, 
and  its  peristaltic  motions.  The  vitreous  humour  often  becomes 
full  of  peculiar  membranous  opacities,  as  a  consequence  of  the 
presence  of  the  cysticercus. 

Treatment. — Removal  by  operation.  The  prospects  for  the  eye 
are  very  much  worse  than  in  the  case  of  a  sub-retinal  cysticercus. 

Blood  Vessels  are  sometimes  formed  in  the  vitreous  humour. 
They  spring  from  the  retinal  vessels,  especially  in  the  neighbourhood 
of  the  optic  disc,  often  in  connection  with  connective  tissue  forma- 
tions which  accompany  haemorrhages  ;  but  sometimes  small  loops 
arise  in  the  neighbourhood  of  the  disc,  without  any  h?cmorrhagic 
disease. 

Persistent  Hyaloid  Artery. — In  intra-uterine  life  the  hyaloid 
artery  is  a  prolongation  of  the  central  artery  of  the  retina,  and 
runs  from  the  papilla  to  the  posterior  surface  of  the  crystalline 
lens.  It  completely  disappears  prior  to  birth,  except  in  those  rare 
cases  where  it  remains  as  an  opaque  string,  which  may  stretclTthe 
whole  way  from  papilla  to  lens,  or  may  extend  only  part  of  the 
way.  It  is  then  thrown  into  Avave-like  movements  by  the  move- 
ments of  the  eyeball,  and  is  easily  recognised  with  the  ophthalmo- 
scope.    It  does  not  usually  cause  any  disturbance  of  vision. 


CHAPTER    XII. 

DISEASES   OF   THE   RETINA. 

Diseases  of  tlie  Retina  may  be  conveniently  grouped  as  follows 
for  the  purpose  of  description  : — Circulatory  Phenomena;  Inflam- 
mation (Retinitis),  Retinal  Hsemorrhages  and  allied  diseases, 
Diseases  of  the  Blood  Vessels,  Atrophy  and  Degeneration,  Injury  by 
Strong  Light,  Tumours,  Parasitic  Disease,  Detachment,  and  Trau- 
matic Affections. 

Alterations  in  the  Retinal  Circulation. 

Hypersemia  and  Anaemia  of  the  retina,  due  to  changes  in  the 
capillary  vessels,  cannot  be  seen  with  the  ophthalmoscope,  hence 
these  terms  are  used  to  denote  apparent  enlargement  of  diminution 
of  the  principal  branches  of  the  central  vessels.  Venous  Engorge- 
ment may  occur  as  a  local  condition,  as  in  papillitis,  retinitis,  throm- 
bosis of  the  central  vein,  or  as  part  of  general  venous  obstruction 
in  cardiac  and  pulmonary  diseases.  Contraction  of  the  Arteries 
may  also  be  due  to  local  disease  of  the  vessels  (embolism,  albuminuric 
retinitis,  etc.)  and  spasm  (malaria,  quinine),  or,  more  rarely,  to 
diminished  blood  supply  from  general  causes  (cholera).  The 
opposite  conditions,  namely,  diminution  in  the  size  of  the  veins,  and 
dilatation  of  the  arteries,  are  rarely  noticeable. 

Pulsation  of  Retinal  Vessels. — Pulsation  in  the  Retinal  Veins 
is  present  under  normal  conditions  in  some  eyes,  and  can  be  produced 
by  slight  pressure  on  the  eyeball  in  all  eyes.  It  is  best  observed 
on  the  optic  disc  and  in  the  upright  image.  In  cases  of  insuffi- 
ciency of  the  aortic  and  tricuspid  valves,  the  venous  pulsation  is 
often  very  marked,  and  extends  some  way  into  the  retina.  Pulsation 
in  the  Retinal  Arteries  in  a  slight  degree  can  be  detected  in  about 
36  per  cent,  of  noi'mal  eyes  (Ballantyne).     But  great  care  is  required 

313 


314  DISEASES   OF   THE  EYE.  [chap.  xii. 

in  order  to  satisfy  oneself  of  its  presence,  and  pulsatory  movements 
communicated  to  the  patient's  head,  or  movements  of  the  ophthal- 
moscope in  the  observer's  hand,  must  be  carefully  excluded.  Arterial 
pulsation  may  appear  as  a  movement  of  the  vessel  as  a  whole  (loco- 
motor pulse),  when  it  is  best  seen  at  a  curve,  or  as  an  alternate 
contraction  and  dilatation  of  the  vessel  (expansile  pulsation).  A 
'  capillary  pulse '  is  only  seen  in  aortic  regurgitation,  and  appears 
as  an  alternate  blanching  and  reddening  of  the  optic  disc,  similar 
to  the  capillary  pulse  seen  under  the  finger  nails.  Another 
variety  of  pulsation  is  the  '  pressure  pulse  '  due  to  increased  intra- 
ocular pressure,  as  seen  in  glaucoma,  or  when  digital  pressure  is 
exerted  on  the  normal  eye.  Arterial  pulsation  occurs  also  in 
some  cases  of  mitral  disease,  in  exophthalmic  goitre,  and  sometimes 
in  ansemia. 

Inflammation  of  the  Retina  :    Retinitis. 

Retinitis,  in  general,  is  characterised  by  the  following  ophthal- 
moscopic appearances  :  diffuse  cloudiness,  especially  of  the  central 
portion  of  the  fundus,  due  to  loss  of  transparency  in  the  retina, 
and  consequent  veiling  of  the  chorioid  ;  the  optic  papilla  becomes 
more  or  less  congested,  with  indistinctness  of  its  outline,  Avhich 
in  the  erect  image  resolves  itself  into  a  delicate  striation  ;  vascular 
engorgement,  the  retinal  veins  especially  becoming  enlarged  and 
tortuous.  The  inflammation  in  some  cases  may  subside  at  this 
stage,  but  as  a  rule  haemorrhages  and  whitish  exudations  soon  make 
their  appearance. 

The  various  forms  of  retinitis  are  distinguished  by  the  pre- 
dominance of  some  of  the  above  signs,  and  also  by  the  peculiar 
appearance  and  grouping  of  the  exudations. 

If  the  optic  papilla  be  not  merely  congested,  but  also  swollen, 
the  condition  is  called  Neuro-Retinitis. 

In  some  cases  of  retinitis  the  chorioid  is  also  involved,  and  to 
these  the  name  Chorio-Retinitis  is  given. 

Inflammation  of  the  retina  is  rarely  a  local  affection,  being  in 
the  majority  of  cases  due  to  general  diseases,  and  hence  it  most 
commonly  occurs  in  both  eyes. 

Syphilitic  Retinitis  (or  Syphilitic  Chorio-Retinitis).  (Plate  III. 
Fig.  1). — Inherited  or  acquired  syphilis  is  liable  to  induce  a  form 


CHAP.  XII.]  THE   RETINA.  315 

of  clironic  diffuse  retinitis.  In  the  acquired  disease  it  is  a  later 
secondary  symptom,  coming  on  between  the  sixth  and  eighteenth 
month,  and  often  in  one  eye  only. 

With  the  Ophthalmoscope  a  slight  opacity  of  the  retina  is  seen 
extending  from  the  papilla  some  distance  into  the  retina,  and 
very  gradually  disappearing  towards  the  equator  of  the  eye.  The 
papilla  is  but  slightly  hyperaunic,  while  its  margins  are  indistinct, 
like  those  of  the  moon  seen  through  a  light  cloud.  The  artery  is 
not  generally  altered,  and  the  vein  is  but  slightly  distended. 
Opacities  in  the  vitreous  humour  are  not  uncommon.  They  may 
be  membranous  or  thread-like,  but  a  diffuse  dust-like  opacity, 
filling  the  whole  vitreous  humour,  is  almost  pathognomonic  of  a 
syphilitic  taint  (p.  299),  and  often  creates  much  difficulty  in  the 
ophthalmoscopic  diagnosis  of  the  retinal  affection. 

Disseminated  chorioidal  changes  in  the  form  of  small  yellowish 
spots  with  pigmentary  deposit,  are  very  frequent,  especially  towards 
the  equator  of  the  eye.  Many  observers,  indeed,  hold  that  the 
whole  process  is  primarily  in  the  chorioid,  and  that  the  retina  is 
only  secondarily  affected.  Fine  whitish  dots  and  pigmentary  changes 
often  occur  about  the  macula  lutea. 

The  hereditary  form  of  the  disease  sometimes  bears  a  resemblance 
to  retinitis  pigmentosa,  but  the  pigmentation  is  not  so  delicate, 
indeed  in  some  cases  there  is  massive  pigmentation,  and  often  it  is 
mingled  with  small  white  atrophic  spots  giving  rise  to  an  appearance 
like  pepper  and  salt.  Atrophy  of  the  optic  disc  and  white  lines  along 
the  vessels  are  often  seen.     The  disease  may  be  ante-natal. 

Occasionally,  instead  of  the  diffuse  retinitis,  syphilis  causes  a 
circumscribed  yellowish-white  exudation  in  the  neighbourhood  of 
the  macula  lutea,  or  on  the  course  of  one  of  the  large  retinal  blood- 
vessels. 

Vision  may  be  but  slightly  affected,  but  in  the  advanced  stages 
it  is  usually  much  lowered.  Central,  or  peripheral,  or  ring  scotomata 
(Fig.  19)  or  concentric  defects  of  the  field,  are  found.  The  scoto- 
mata are  often  positive — i.e.  they  can  be  seen  by  the  patient  as 
dark  spots  in  the  field.  Night-blindness  is  a  constant  symptom,  and 
the  light-sense  is  enormously  diminished.  The  patients  sometimes 
complain  of  sparks  or  lights,  which  seem  to  dance  before  their 
eyes,  and  occasionally  also  of  a  diminution  in  the  size  (micropsia) 
of  objects,  or  of  a  distortion  (metamorphopsia)  of  their  outlines. 


31()  DISEASES   OF    THE   EYE.  [chap.  xii. 

The  micropsia  is  believed  to  be  due  to  a  separation  from  each 
other  of  tlie  elements  of  the  layer  of  rods  and  cones  by  sub-retinal 
exudation.  The  image  of  an  object  then  comes  into  relation  with 
fewer  of  these  elements,  and  hence  the  mental  impression  is  that 
of  a  smaller  object  than  is  conveyed  by  the  image  formed  in  the 
sound  eye,  or  on  a  sound  part  of  the  same  retina. 

The  Progress  of  the  Disease  is  very  slow,  and  is  liable  to  relapses. 
In  the  late  stages  extensive  pigmentary  degeneration  of  the  retina 
may  come  on,  or  disseminated  chorioiditis  (Plate  III.  Fig.  1).  But 
if  the  case  come  under  suitable  treatment  in  an  early  stage,  a  cure 
may  often  be  effected. 

Treatment. — The  only  remedy  which  has  been  of  real  value  is 
mercury,  and  that  in  an  early  stage.  Probably  salvarsan  will  prove 
useful.  Mercury  should  be  used  in  a  protracted  course  of  some 
weeks  by  inunction,  combined  at  discretion  with  small  doses  of 
calomel  internally.  Or,  the  method  by  intra-muscular  injection 
of  mercury  may  be  employed.  If  mercurialisation  be  effected,  it 
should  not  go  further  than  very  slight  stomatitis.  Turkish  baths, 
and  the  artificial  leech  at  the  temple,  may  be  employed  as  adjuncts 
to  the  treatment.  When  the  mercurial  course  has  been  completed, 
iodide  of  potassium  should  be  prescribed  as  an  after-treatment. 
Complete  rest  of  the  eyes,  and  protection  from  strong  light  by  dark 
glasses,  are  also  necessary  in  this,  as  in  many  forms  of  retinitis. 

Retinitis  Albuminurica  occurs  as  a  complication  in  many  cases 
of  chronic  nephritis,  in  some  few  cases  of  acute  nephritis,  and  in  the 
albuminuria  of  pregnancy.  It  is  most  common  with  the  small 
granular  kidney,  but  may  attend  any  chronic  form  of  Bright' s 
disease,  and  occurs  in  32  per  cent,  of  these  cases,  and  in  52  per  cent, 
of  those  with  azotfemia  (nitrogenous  retention).  The  arterial  ten- 
sion is  always  high  when  retinitis  is  present,  even  in  the  young. 
It  is  rare  in  children,  reaches  its  maximum  between  thirty  and 
forty  years  of  age,  after  which  it  again  becomes  rarer.  It  is  com- 
moner in  men  than  in  women. 

The  Defect  of  Vision  in  the  chronic  form,  although  often  the  first 
symptom  which  causes  the  patient  to  seek  advice,  is  associated 
rather  with  a  late  stage  of  the  kidney  disease,  and  with  hypertrophy 
of  the  heart.  Retinitis  may  be  present  before  albumen  is  found  in 
the  urine.  Both  eyes  as  a  rule  are  affected,  although  often  not 
equally  so.     Vision  is  much  lowered,  and  even  perception  of  light 


ft  iiijtti Iliad  X' 


PLATE    V. 

{To  face  page  316.) 

Fig.  1. — There  is  a  slight  cloudiness  of  the  retina,  veiling  the  retinal 
vessels  and  the  outline  of  the  optic  disc.  Note  the  flame-shaped 
retinal  haemorrhages  and  round  soft-edged  white  exudations,  some 
of  which  lie  anterior  to  the  retinal  vessels.  The  fovea  centralis  is 
surrounded  by  brilliant  white  radiating  lines  and  dots,  the  so-called 
'  star  at  the  macula  '  which  is  very  suggestive  of  albuminuric  retinitis. 

Fig.  2. — The  detached  portion  of  the  retina  is  of  a  bluish-grey  colour  and 
is  thrown  into  folds,  on  the  elevations  and  depressions  of  which  the 
dark  retinal  vessels  pursue  an  irregular  wavy  course.  To  the  right 
the  detachment  is  shallower  and  the  retina  has  partially  preserved 
its  transparency.  A  triangular  rent  in  the  retina  is  visible  to  the 
left. 


Plate  V. 


Fig.   J.     Albuminuric  Retinitis. 


Fig.  2.     Detachment  of  the  Retina. 


CHAP.  XII.]  THE   RETINA.  317 

may  be  wanting  ;  there  may  be  enlargement  of  the  blind  spot 
and  central  scotomata,  but  the  peripheral  field  is  normal.  The 
blindness  is  not  always  all  due  to  organic  changes  in  the  retina, 
being  often  largely  the  result  of  uraemia.  (See  Ur?emic  Amblyopia, 
chap,  xiv.) 

OphthaJmoscopie  Appearances  (Plate  V.  Fig.  1). — These  are 
venous  hyper^rmia,  with  oedematous  swelling  of  the  papilla,  and  of 
the  retina  in  its  neighbourhood  ;  hjiemorrhages  on  the  papilla,  and 
in  the  nerve-fibre  layer  of  the  retina  ;  and  round  or  irregularly 
shaped  white  spots  in  the  retina,  arranged  in  a  zone  around  the 
papilla,  some  three  papilla  diameters  removed  from  it.  These 
changes  take  place  in  the  order  enumerated.  The  hyper?emia  and 
engorgement  of  the  veins,  often  very  great,  become  less,  according 
as  the  white  spots  become  more  developed.  Near  the  macula  lutea 
no  very  coarse  changes  usually  occur  ;  but  fine  white  dots  are 
found,  with  a  star-like  arrangement  converging  towards  the  macula. 
In  some  cases  these  fine  white  dots  are  present  only  on  the  inner 
side  of  the  macula  in  the  space  between  it  and  the  papilla. 

The  macular  star  is  also  met  with  in  retinitis  from  diabetes,  in 
embolism  of  the  central  artery,  arterio-sclerosis,  chlorosis,  syphilitic 
neuro-retinitis,  leuca}mia,  and  in  some  cases  of  papilloedema  from 
cerebral  tumour. 

The  degree  in  which  all  these  different  changes  are  present 
varies  in  different  cases,  no  one  of  them  being  pathognomonic  of 
the  kidney  affection,  but  rather  the  grouping  of  the  whole  picture 
being  suggestive.  Sometimes  the  papillitis  is  so  intense  as  to  simulate 
that  known  as  congestion  papilla  in  cases  of  intra-cranial  tumour  ; 
while  the  white  spots  are  sometimes  developed  to  such  a  degree 
as  to  become  confluent,  and  to  form  one  large  white  plaque.  Again, 
the  papillitis,  or  white  spots,  or  both,  may  be  but  slightly  marked. 
The  number  and  size  of  the  haemorrhages  are  also  liable  to  great 
variation.  Detachment  of  the  retina  has  been  observed  in  a  few 
cases  ;  and  sometimes  the  haemorrhages  burst  into  the  vitreous 
humour. 

Some  of  the  white  spots  are  caused  by  exudations  of  fibrinous 
coagula  in  the  outer  layers  of  the  retina  (the  retinal  vessels  passing 
over  them)  and  of  gangliform  degeneration  of  the  nerve-fibre  layer 
(the  retinal  vessels  hidden  by  them).  The  white  star  at  the  macula 
lutea  is  caused  by  the  deposit  of  blocks  of  fibrin,  which  are  dis- 


318  DISEASES    OF    THE   EYE.  [chap.  xit. 


tributed  radially  owing  to  the  anatomical  structure  of  the  macula. 
Small  aneurismal  dilatations  of  the  arteries  occur  very  occasionally. 

The  retinal  changes  are  the  result  of  the  renal  disease.  Cells 
containing  fat  or  lipoid  substance  are  also  seen  in  the  retina  ;  some 
believe  them  to  be  wandering  pigment  cells  which  have  lost  their 
pigment.  The  retinal  changes  are  not  caused  by  arterio-sclerosis, 
for  the  vessels  are  usually  healthy  in  early  stages  and  in  acute  and 
puerperal  cases,  although  in  the  later  stages  of  chronic  cases  they 
do  become  diseased,  by  retardation  of  the  blood-stream  from  failure 
of  the  heart,  or  from  diminution  in  size  of  the  smaller  retinal  vessels 
(Leber). 

Prognosis. — In  chronic  cases  the  prognosis  as  regards  the  patient's 
life  is  bad.  The  majority  die  within  eighteen  months  or  two  years  ; 
but,  if  the  general  disease  remain  stationary,  or  improve,  or  recover, 
the  retinal  changes  may  improve  or  disappear,  and  may  leave  the 
retina  with  normal  appearances  and  functions  ;  or,  the  swelling, 
hyperemia,  white  spots,  and  hcTmorrhages  may  give  place  to  optic 
atrophy,  with  diminution  in  size  of  the  arteries,  pigmentary  altera- 
tions in  the  retina,  and  blindness.  In  the  albuminuria  of  pregnancy, 
and  in  that  due  to  acute  nephritis,  the  retinal  complication  may 
disappear  with  the  renal  disorder,  leaving  good  vision. 

Treatment. — No  treatment  other  than  that  for  the  primary  renal 
disease  is  of  avail.  Taking  into  consideration  the  serious  import 
of  this  eye-symptom  for  the  life  of  the  patient,  it  is  a  question 
whether,  in  many  cases  of  pregnancy  with  albuminuric  retinitis, 
abortion  should  not  be  resorted  to,  especially  if  the  pregnancy  have 
still  some  months  to  run.  But,  on  the  whole,  the  prognosis  is  more 
favourable  in  the  albuminuria  of  pregnancy  than  in  interstitial 
nephritis. 

Retinal  Affections  in  Diabetes.— There  is  no  one  condition  of 
the  retina  characteristic  of  diabetes,  although  undoubtedly  retinal 
affections  occasionally  do  complicate  it  in  an  advanced  stage.  The 
changes  are  not  suggestive  of  inflammation,  but  rather  of  degenera- 
tion. Small  retinal  haemorrhages,  with  fine  changes  in  the  form 
of  glistening  dots  about  the  macula  lutea,  somewhat  similar  in 
appearance  to  those  which  occur  in  Bright's  disease,  except  that  they 
rarely  form  the  well-marked  star,  are  perhaps  the  most  common  and 
suggestive  appearances.  In  other  cases  retinal  hcTmorrhages  alone 
are  found,  and  in  others  thrombosis  of  the  central  vein  ;  while,  again. 


CHAP.   XTT.]  THE   RETINA.  310 

the  so-called  typical  appearances  of  iiriglit's  disease  may  be  pre- 
sented. There  are  often  opacities  of  hfcmorrhagic  origin  in  the 
vitreous  humour,  which,  if  copious,  may  destroy  vision. 

It  is  an  important  rule  of  practice  that,  in  all  cases  of  retinal 
hremorrhages  and  of  thrombosis,  the  urine  should  be  examined 
for  sugar  and  albimien.  The  retinal  disease  is  sometimes  the  first 
indication  of  the  general  disorder. 

Embolism  of  the  central  artery,  and  thrombosis  of  the  central 
vein,  have  been  observed  in  diabetes. 

With  the  marked  lipsemia  which  is  present  in  some  cases  of 
diabetes,  the  retinal  vessels  appear  as  bright  lines  on  a  red  back- 
ground, the  arteries  and  veins  being  difficult  to  distinguish  from 
each  other.  This  is  not  due  to  a  fatty  embolism  of  the  vessels,  but 
rather  to  the  blood  being  altered  to  a  fat-emulsion  throughout  the 
entire  system.     (See  also  Glycosuric  Amblyopia.) 

Retinitis  Leucsemica. — In  not  more  than  one-third  or  one- 
fourth  of  the  cases  of  leucocythemia,  or  pseudo-leuc?emia,  does  a 
retinal  affection  occur,  and  it  is  not  always  of  the  same  type.  It 
may  consist  in  a  slight  diffuse  retinitis,  accompanied  by  some  ex- 
travasations of  pale  blood  ;  while  the  blood-vessels  are  also  pale, 
the  veins  being  much  enlarged,  and  flattened  rather  than  over- 
distended,  the  arteries  small,  and  the  chorioid  of  an  orange-yellow 
colour.  Or,  it  may  resemble  a  case  of  ordinary  hsemorrhagic 
retinitis. 

The  Apfearances  most  characteristic  of  the  affection  are  :  a  pale 
papilla  with  indistinct  margins  ;  slight  opacity  of  the  retina,  especi- 
ally along  the  vessels  ;  small  haemorrhages  ;  round,  white,  elevated 
spots  up  to  2  mm.  in  diameter,  with  a  hsemorrhagic  halo,  situated 
by  preference  towards  the  periphery  of  the  fundus  and  at  the  macula 
lutea,  but  not  at  all,  or  only  in  very  severe  cases,  in  the  zone  between 
the  macula  and  the  equator  of  the  eye.  These  white  spots  consist 
of  extravasations  of  leucaemic  blood,  the  result,  probably,  of  dia- 
pedesis,  and  they  are  sometimes  distinctly  prominent. 

Vision  may  be  but  little  affected  if  the  macula  lutea  be  fairly 
free.  Haemorrhage  into  the  vitreous  humour  may  cause  complete 
blindness. 

Metastatic  Retinitis  is  observed  as  the  result  of  septic  embolism 
of  the  retinal  arteries  in  septicaemia  after  surgical  operations,  etc., 
and  very  frequently  in  cases  of  metria,  and  it  is  usually,  in  the 


320  DISEASES   OF   THE   EYE.  [chap.  xii. 


latter  condition,  a  fatal  sign.  In  an  early  stage  the  ophthalmoscope 
shows  a  number  of  small  haemorrhages  in  the  retina,  with  general 
cloudiness  of  the  retinal  tisues,  while  the  actual  embolisms,  which 
are  usually  multiple,  may  not  be  visible.  The  inflammation  makes 
rapid  progress,  and  becomes  purulent,  soon  destroying  sight,  and 
extending  to  the  chorioid,  iris,  and  vitreous  humour,  until  finally 
the  stage  of  panophthalmitis  is  reached.  The  retina  is  sometimes 
alone  the  primary  seat  of  the  embolic  attack,  and  sometimes  the 
chorioid  is  also  involved.  The  embolisms  are  often  little  more  than 
masses  of  micrococci.  Mild  cases,  which  stop  short  of  suppuration, 
also  occur,  and  are  probably  from  toxins  only. 

The  retina,  of  course,  becomes  secondarily  implicated  in  many 
purulent  processes,  which  commence  in  other  parts  of  the  eye. 

For  Retinitis  caused  by  strong  light  see  Injury  of  the  Eetina 
by  Strong  Light. 

Eetinal  H.5:moerhages  and  Allied  Diseases. 

Retinal  Haemorrhages. — Haemorrhages  seen  with  the  ophthal- 
moscope nearly  always  have  their  origin  in  the  retina,  and  are  most 
frequently  observed  in  persons  over  forty  or  fifty  years  of  age, 
although  they  are  not  uncommon  in  the  young.  Fresh  haemorrhages 
are  bright  red,  but  they  become  darker  in  colour  after  a  while,  or  if 
the  layer  of  blood  be  very  thick  they  even  take  on  a  tinge  of  black. 
Their  shape  varies  according  to  their  depth  in  the  retina  ;  if  they  be 
situated  in  the  nerve-fibre  layer  they  appear  flame  shaped  and  radi- 
ally striate  (Plate  V.  Fig.  1,  and  Plate  YII.  Fig.  2),  but  when  they 
occupy  the  deeper  layers  they  are  round  or  blotchy.  Haemorrhages 
may  be  present  in  any  part  of  the  fundus,  and  may  vary  in  size  from 
a  mere  speck  to  a  large  patch  several  times  the  size  of  the  optic  disc. 
In  some  cases,  only  one  or  two  minute  spots  of  blood  are  visible, 
while  in  others  the  whole  retina  is  splashed  over  with  them.  They 
may  break  through  into  the  vitreous  humour. 

Pre-retinal  or  Suhhyaloid  hcemorrhages,  in  which  the  blood  is  poured 
out  over  a  fairly  large  surface,  either  immediately  under  the  membrana 
limitans  interna,  or  between  it  and  the  vitreous  humour,  usually  occur 
in  the  macular  region.  They  are  semicircular  or  boat-shaped,  their  upper 
margin  being  limited  by  a  horizontal  line.  Ihe  red  colour  disappears  in 
the  upper  part  of  the  haemorrhage  owing  to  the  subsidence  of  the  blood- 
corpuscules.  One  or  more  of  the  retinal  blood-vessels  may  be  hidden 
from  view  where  they  pass  under  the  layer  of  blood. 


CHAP.  XII.]  THE   RETINA.  3^1 

Sympmns. — Peripheral  haemorrhages  may  not  cause  any  visual 
symptoms  appreciable  to  the  patient,  otherwise  the  loss  of  sight 
comes  on  suddenly  and  is  attended  with  the  development  of  a  posi- 
tive scotoma.  There  may  be  metamorphopsia.  In  some  cases  the 
patient  notices  a  reddish  cloud  before  the  eye. 

Causes. — Eetinal  hsemorrhages  usually  form  part  of  the  ophthal- 
moscopic picture  in  optic  neuritis  and  various  forms  of  retinitis, 
when  they  are  only  of  secondary  importance.  Other  causes  are 
diseased  condition  of  the  blood  such  as  pernicious  anaemia,  leu- 
caemia, purpura,  scurvy,  etc.  ;  cardiac  disease ;  diseases  of  the 
retinal  blood-vessels,  including  syphilitic  and  possibly  tubercular 
disease,  angio-sclerosis,  and  thrombosis ;  in  embolism  there  are 
usually  few  or  none. 

Retinal  haemorrhage  may  also  be  caused  by  irregular  or  suppressed 
menstruation,  by  severe  loss  of  blood,  by  venous  congestion  from  pul- 
monary stenosis  or  severe  compression  of  the  thorax  or  neck,  and  from 
pressure  during  birth  in  new-born  infants. 

Of  a  different  origin  are  the  hasmorrhages  which  result  from  injury  or 
sudden  reduction  of  the  intra-ocular  pressure  after  operations  (see  Glaucoma, 
Cataract). 

The  prognosis  in  cases  of  retinal  haemorrhage  depends  to  a  great 
extent  on  the  constitutional  condition  wdth  w^iich  they  are  associ- 
ated. They  may  remain  unaltered  for  many  months.  Sometimes 
the  blood  becomes  absorbed  without  leaving  any  traces  behind,  but 
if  at  all  large  a  greyish  or  white  patch  is  formed,  but  pigmentation 
is  less  common. 

Eetinal  haemorrhages,  however  slight,  even  though  unaccom- 
panied by  retinitis,  must  be  looked  upon  with  grave  suspicion, 
more  especially  when  they  occur  in  people  past  middle  age  ;  for 
they  may  be  the  forerunners  of  albuminuric  retinitis  or  furnish  the 
first  indication  of  diabetes  or  of  local  or  general  angio-sclerosis, 
and  many  of  these  patients  die  from  cerebral  haemorrhage. 

Pre-retinal  haemorrhages  often  disappear  completely  without  in- 
juring the  sight,  but  they  are  liable,  like  most  haemorrhages,  to  recur. 

Treatment. — Active  measures  are  of  little  use.  Cold  compresses 
at  first,  with  a  pressure  bandage,  and  dry  cupping  to  the  temple, 
may  be  employed.  The  general  state  of  the  patient  must  be  at- 
tended to,  with  rest  of  the  body.  Iodide  of  potassium  and  sub- 
conjunctival saline  injections  may  be  of  use. 
21 


322  DISEASES   OF    THE   EYE.  [chap.  xii. 


It  will  be  advisable  to  describe  in  this  place  certain  types  of 
disease  wliieli  aie  closely  associated  with  or  directly  dependent  upon 
extravasation  of  blood  into  the  retina,  namely,  Ketinitis  Proliferans, 
Ketinitis  Exudativa,  and  Ketinitis  Circinata.  Hcijmorrhagic  re- 
tinitis will  be  described  under  Thrombosis  of  the  Central  Vein. 


Development  of  Connective  Tissue  in  the  Retina,  or  Retinitis  Proliferans.— 

Extensive  white  or  bluisli-white  striae,  formed  of  connective  tissue,  are 
sometimes  seen  in  the  retina,  and  may  even  conceal  the  vessels  and 
papilla.  They  project  into  the  vitreous  humour,  and  contain  newly 
formed  vessels,  which  are  prolongations  of  the  retinal  vessels.  These 
striae  are  the  result  of  haemorrhages  especially  when  near  the  optic  disc, 
traumatic  or  otherwise,  and  of  inflammatory  processes.  Haemorrhages 
in  the  retina,  or  in  the  vitreous  humour,  or  in  both,  are  generally 
present  at  some  period.  Vision  is  sometimes  but  slightly  affected,  but  the 
danger  of  recurrence  of  the  haemorrhages  renders  the  ultimate  prognosis 
unfavourable  as  a  rule.     Detachment  of  the  retina  may  occur. 

This  disease  is  chiefly  seen  in  young  people  (see  p.  301)  with  relapsing 
haemorrhages  into  the  vitreous  humour,  but  it  occurs  occasionally  in  those 
past  middle  age. 

Treatment. — Heurteloup's  leech.  Iodide  of  potassium,  or  perchloride 
of  mercury.  Lactate  of  calcium.  Thyroid  extract.  Some  cases  are  on 
record  where,  one  eye  having  been  lost  from  this  disease,  and  the  sight 
of  the  other  eye  seriously  threatened,  the  common  carotid  was  ligatured 
on  the  side  of  the  second  eye,  with  the  desired  result  of  arresting  the 
recurrence  of  haemorrhages.  The  effect  of  the  procedure  is  held  to  be  due 
to  reduction  of  the  pressure  on  the  walls  of  the  ophthalmic  artery. 

Retinitis  Exudativa  (Retinitis  Haemorrhagica  Externa)  (Coats).— This  is 
a  very  chronic  and  insidious  disease  which  occurs  in  young  persons  and 
only  exceptionally  involves  both  eyes.  There  is  usually  nothing  in  the 
general  health  or  family  history  to  which  the  disease  can  be  attributed. 

The  exudation  appears  in  the  shape  of  one  or  more  prominent  opaque 
white  or  yellowish  masses,  which  always  underlie  the  retinal  vessels. 
Haemorrhages  are  nearly  alwaj^s  present  on  the  sxu-face  or  at  the  periphery 
of  the  mass.  The  older  exudations  may  be  greenish  or  tendinous  in 
appearance.  Most  cases  present  evidences  of  vascular  disease,  such  as 
white  lines  along  the  vessels,  fusiform  dilatations,  beading,  or  newly 
formed  vascular  loops,  brushes  or  glomeruli.  The  disease  progresses 
slowly  for  years,  with  varying  changes  in  appearance,  due  to  fibrous 
cicatricial  changes  in  the  older  masses  combined  with  the  formation  of 
fresh  exudations  and  haemorrhages.  The  eye  is  ultimately  lost  from  de- 
tachment of  the  retina,  secondary  cataract,  and  iritis  with  low  tension, 
or  glaucoma  may  supervene. 

The  most  constant  microscopical  lesion  is  a  fibrous  tissue  mass  between 
the  retina  and  the  chorioid,  with  evidences  of  degenerative  changes.  In 
many  cases  the  retinal  vessels  show  various  forms  of  disease. 

Retinitis  Circinata  is  a  rare  disease.     It  occurs  mostly  in  old  people, 


CHAP,  xii.'j  THE   RETINA.  3^3 

chiefly  women,  but  sometimes  in  the  yonng,  and  is  characterised  by 
remarkable  appearances.  At  tlie  macula  there  is  a  grey  or  yellowish 
cloudy  patch,  which  may  attain  the  size  of  the  papilla,  and  sometimes 
presents  hseinorrhages  on  its  surface  ;  surrounding  tliis,  but  separated 
from  it  by  a  healthy  zone,  is  a  ring  composed  of  numerous  closely  set, 
small  white  spots,  which  are  confluent  in  places.  The  sight  gradually 
becomes  much  deteriorated.  A  large  central  scotoma  develops,  and  vision 
is  finally  reduced  to  finger-counting  centrally,  although  for  a  long  time 
the  peripheral  field  may  not  become  contracted.  Total  blindness  rarely 
results. 

A  case  has  been  recorded  of  complete  recovery  with  disappearance  of 
the  ophthalmoscopic  changes.  This  disease  is  the  result  of  hsemorrhage, 
and  is  closely  allied  to  exudative  retinitis.  Coats  has  indeed  recorded  a 
case  of  a  patient  who  had  massive  exudation  in  one  eye  and  retinitis 
circinata  in  the  other,  moreover  ophthalmoscopic  evidences  of  vascular 
disease  such  as  arterio-sclerosis  are  often  present  in  retinitis  circinata. 

Capillary  Angiomatosis  of  the  Retina  (Von  Hippel's  Disease). — ^This 
rare  affection  begins  in  the  second  or  third  decade  of  life,  but  continues 
to  progress  for  many  years  and  ultimately  ends  in  blindness.  Both  eyes 
are  affected,  but  a  variable  interval  elapses  before  the  onset  of  the  disease 
in  the  second  eye.  The  ophthalmoscopic  appearance,  which  is  very  char- 
acteristic, consists  in  the  formation,  usually  towards  the  periphery,  of 
oval  or  spherical  pink  or  yellowish  bodies,  in  which  end  abruptly  two 
enormously  dilated  and  tortuous  vessels,  an  artery  and  a  vein,  but  the 
latter  is  much  paler  in  colour  than  a  normal  vein.  The  small  tumour 
is  composed  of  a  capillary  vascular  plexus  with  some  supporting  neuroglial 
tissue.  The  tumours  increase  in  size  while  others  appear.  Haemorrhages 
and  brilliant  white  spots  are  also  seen.  Finally  the  retina  becomes 
detached,  with  low  tension,  or  glaucoma  sets  in. 

Epistaxis  and  headache  have  been  noted  in  several  of  the  cases,  and, 
in  a  few,  intracranial  cysts  have  been  discovered  post  mortem.  The 
disease  has  occurred  in  two  members  of  a  family;  its  cause  is  unknown. 

Diseases  of  the  Ketinal  Vessels. 

The  vessels  of  the  retina  become  affected  secondarily,  in  various 
forms  of  retinal  disease,  and  in  some  of  the  diseases  just  dealt  with 
vascular  disease  may  play  a  prominent  part ;  but  this  section  will 
be  concerned  with  primary  disease  of  the  retinal  vessels,  with  ob- 
struction of  the  circulation  in  the  retina,  and  with  the  ophthal- 
moscopic evidences  of  vascular  disease. 

Sclerosis  of  the  Retinal  Vessels.— The  arteries  are  more  Hable  to 
this  condition  than  the  veins ;  it  takes  the  form  of  an  endo-  or 
perivasculitis.  In  the  case  of  the  arteries  the  intima  is  most 
frequently  involved,  but  periarteritis  may  also  occur,  while  in  the 
veins  endophlebitis  is  rare  and  periphlebitis  fairly  common.    Endar- 


324  DISEASES   OF    THE   EYE.  [chap.  xtl. 


teritis  reveals  its  presence  by  narrowing  of  the  blood  column,  and 
perivasculitis  by  the  appearance  of  white  lines  along  the  vessels. 
The  disease  usually  begins  in  the  large  tiunks  on  the  papilla,  and 
may  not  extend  much  beyond  the  latter,  as  in  some  cases  of  optic 
atrophy  (Plate  VIII.  Fig.  2)  ;  while  in  other  cases  (Bright's  disease, 
hereditary  syphilis)  it  involves  the  small  branches  as  well,  and  pro- 
motes thrombosis  and  retinal  apoplexies,  and  may  even  ultimately 
lead  to  obliteration  of  the  lumen  of  the  vessels,  so  that  they  look  like 
white  branching  streaks. 

The  alterations  in  the  vessels  consist  in  engorgement  and  tortu- 
osity ;  centripetal  venous  pulsation,  which,  according  to  Eaehlmann, 
is  seldom  absent ;  the  arteries  become  smaller,  the  light  streak 
brighter,  and  the  whole  vessel  is  lighter  in  colour  ('  silver  wire  ar- 
teries '),  its  walls  become  less  transparent,  and  its  increased  rigidity 
is  shown  by  the  indentation  of  the  veins  where  it  may  happen  to 
pass  over  them  ;  pulsation  is  more  easily  produced  on  pressure  than 
in  a  normal  eye.  In  more  advanced  cases  the  contour  of  the  vessels 
becomes  irregular,  they  may  exhibit  localised  constrictions,  or  alter- 
nate constrictions  and  dilatations  ;  further,  the  constricted  portion 
of  the  vessel  may  be  so  limited  as  to  involve  only  a  couple  of  milli- 
metres of  its  length,  and  is  then  very  liable  to  be  overlooked  ;  white 
shining  scale-like  spots  are  sometimes  seen  on  the  surface  of  the 
arteries,  especially  in  syphilis  (according  to  Haab)  ;  finally  beading 
and  varicosity  of  the  veins,  aneurismal  dilatations  of  the  arteries, 
arterio-venous  communications  and  newly  formed  vascular  loops 
or  glomeruli  have  all  been  observed  to  occur. 

Three  of  the  earliest  signs  are  :  a  corkscrew-like  appearance  in 
the  small  arterial  twigs,  especially  involving  the  macular  branches  ; 
'  silver-wire '  arteries  causing  more  or  less  displacement  of  the 
underlying  veins,  where  they  cross  the  latter  (Gunn's  sign)  ;  and 
lastly,  a  characteristic  dull  red  colour  of  the  optic  disc. 

The  degree  of  pressure  exerted  by  the  artery  on  the  vein  may 
be  so  slight  as  merely  to  flatten  the  vein,  or  push  it  aside  in  the 
direction  of  the  blood-current  in  the  artery,  while  at  other  times  it 
may  be  sufficient  to  constrict  the  underlying  vein,  which  then 
appears  swollen  at  either  side  of  the  artery  (so-called  "  banking  " 
of  a  vein)  ;  or,  again,  an  engorgement  of  the  vein  on  the  distal  side 
of  the  artery  may  show  that  the  circulation  in  the  vein  is  decidedly 
impeded.     But  in  all  these  cases  the  artery  has  lost  its  transparency. 


CHAP,  xn.]  THE   BET  IN  A.  325 

and  the  vein  can  no  longer  be  seen  underneath  it  as  is  the  case  when 
normal  vessels  cross. 

Symptoms. — Unless  secondary  results  ensue  such  as  hsemorrhages 
or  obstruction  of  the  circulation  leading  to  embolism  and  throm- 
bosis and  retinal  degeneration,  there  may  be  no  visual  defect. 

Etiology. — The  changes  in  the  blood-vessels  are  probably  caused 
by  disturbance  of  the  nutrition,  as  well  as  by  toxins  circulating  in 
the  blood.  The  conditions  which  promote  it  are  senility,  chronic 
nephritis,  diabetes,  syphilis,  poisons  such  as  lead,  alcohol,  and  phos- 
phorus. Angio-sclerosis  sometimes  occurs  in  the  young  and  is 
hereditary.  Intestinal  auto-intoxication  has  also  been  suggested 
as  a  cause. 

Obstruction  of  the  Central  Artery  of  the  Retina  including  Em- 
boUsm  and  Thrombosis. — Complete  obstruction  of  the  central  artery 
of  the  retina,  whether  it  be  brought  about  by  embolism,  thrombosis, 
or  by  extreme  constriction,  produces  a  very  definite  ophthal- 
moscopic picture  (Plate  VII.  Fig.  1).  Sudden  or  very  rapid  blind- 
ness, beginning  at  the  periphery  of  the  field,  and  advancing  towards 
the  centre,  is  the  only  symptom  experienced  by  the  patient. 

Immediately  after  the  attack,  the  Ophthalmoscope  shows  a  marked 
pallor  of  the  papilla,  while  the  artery  and  its  branches  are  much 
diminished  in  size  or  are  empty  of  blood,  resembling  fine  white 
threads,  and  the  veins  are  smaller  at  the  papilla,  but  somewhat  in- 
'creased  in  size  towards  the  periphery.  Pressure  on  the  eyeball  pro- 
duces neither  pulsation  nor  change  in  calibre  of  the  vessels,  as  it 
does  in  a  sound  eye.  Usually,  within  a  few  hours,  the  central  region 
of  the  retina  begins  to  assume  a  greyish-white  opaque  appearance, 
consequent  on  degeneration  of  the  ganglionic  layer  with  perhaps 
oedema  of  the  nerve-fibre  layer,  in  the  midst  of  which  the  macula 
lutea  is  seen  as  a  cherry-red  spot.  The  little  blood  contained  in  the 
vessels  may  soon  be  observed  to  divide  into  short  columns  with 
colourless  interspaces,  and  these  short  columns  move  along  the 
vessels  with  a  slow  jerky  motion.  Minute  haemorrhages  sometimes 
occur,  most  commonly  between  the  macula  and  the  papilla,  but 
they  are  never  numerous. 

The  cherry-red  spot  at  the  macula  lutea  is  not  due  to  haemor- 
rhage. It  is  a  contrast  effect,  the  red  colour  of  the  chorioid  shining 
through,  owing  to  the  retina  being  very  thin  in  this  region. 

The  cloudiness  of  the  retina  passes  away  in  a  few  weeks,  and  with 


326  DISEASES   OF   THE   EYE.  [chap.  xii. 

it  the  peculiar  appearance  of  the  macula  lutea,  while  atrophy  of 
the  retina  and  papilla  supervene.  A  white  star,  such  as  one  sees 
in  albuminuric  retinitis,  sometimes  makes  its  appearance  at  the 
macula. 

In  some  cases  the  embolism  or  obstruction  occurs  in  a  branch  only 
of  the  central  artery.  In  these  cases  the  cloudiness  and  the  defect 
of  vision  are  confined  to  the  part  of  the  retina  supplied  by  the 
obstructed  branch  (Fig.  14). 

In  obstruction  from  arterio-sclerosis  and  thrombosis  there  is 
often  a  history  of  previous  attacks  of  transient  blindness,  in  one 
or  both  eyes,  and  of  faintness,  giddiness,  and  headache  at  the  onset 
of  the  blindness. 

There  is  a  tendency  nowadays  on  the  part  of  some  writers  to  attribute 
most  cases  of  obstruction  of  the  central  artery  to  endarteritis  rather  than 
to  embohsm,  and  the  sudden  cessation  of  the  circulation,  they  say,  is  brought 
about  by  extreme  constriction  of  the  vessel,  associated  with  a  sudden  fall 
in  the  general  blood-pressure,  in  consequence  of  which  the  blood  can  no 
longer  be  forced  through  the  very  small  lumen.  There  is  no  doubt  that 
in  many  cases,  of  so-called  embolism,  careful  examination  of  the  patient 
fails  to  reveal  any  possible  source  from  which  an  embolus  could  originate. 
In  rare  cases,  of  which  we  have  recorded  one  lately  in  a  boy,  sudden  loss 
of  vision  occurs,  with  the  symptoms  of  obstruction  of  the  retinal  circula- 
tion, in  both  eyes.  The  loss  may  be  simultaneous  in  both  eyes  or' there 
may  be  an  interval  between  the  onset  in  each  eye.  These  cases  of  bilateral 
obstruction,  unless  the  loss  of  vision  occurs  simultaneously,  or  nearly  so, 
in  both  eyes,  often  recover  fair  vision. 

Prognosis. — Vision  may  improve  for  a  time,  but  when  atrophy 
commences  it  falls  back  ;  and,  finally,  power  of  perception  of  light 
is  lost.  Cases  of  embolism  of  a  branch  of  the  central  artery  are 
more  likely  to  recover. 

Causes. — Endocarditis  ;  mitral  disease  ;  aneurism  of  the  aorta  ; 
pregnancy  ;  angio-sclerosis.  A  few  cases  of  chorea  with  embolism 
of  the  central  artery  are  recorded.  But  it  occurs,  too,  in  apparently 
healthy  persons,  without  any  discoverable  cause. 

Thrombosis  is  apt  to  be  caused  by  any  condition  which  slows 
the  flow  of  blood,  disease  of  the  walls  of  the  vessels,  or  alteration  in 
the  quantity  or  quality  of  the  blood. 

Treatment. — Paracentesis  of  the  anterior  chamber  has  been 
tried  with  the  object  of  suddenly  reducing  the  tension,  and  thereby 
causing  a  sudden  rush  of  blood  behind  the  obstruction  which  may 


ciiAr.  xiT.]  THE   RETINA.  327 

sweep  the  latter  away.  Such  attempts  have  very  rarely  been  suc- 
cessful, and  can  be  of  avail  only  if  employed  almost  immediately 
after  the  attack  of  blindness  ;  that  is  to  say,  before  the  retinal 
tissue  dies. 

Several  cases  have  been  published  in  which  the  circulation, 
which  probably  was  not  completely  impeded  by  the  embolus,  or 
thrombus,  was  restored,  and  good  vision  regained  ;  the  recovery 
being  probably  due  to  the  manipulations  of  the  eyeball  made  in 
each  case  for  the  purpose  of  observing  the  effect  of  pressure  on 
the  vessels.  In  fresh  cases,  massage  of  the  eyeball  suitably  applied 
would,  therefore,  always  be  worth  the  trial. 

Amaurosis  Fugax. — Very  closely  related  to  the  cases  of  permanent 
obstruction,  and  differing  from  them  probably  only  in  degree,  are  those 
characterised  by  the  occurrence  of  repeated  attacks  of  sudden  but  tem- 
porary failure  of  sight,  complete  or  partial. 

The  obscurations  of  sight  in  amaurosis  fugax  are  due  to  direct  inter- 
ference with  the  retinal  blood-supply,  and  are  independent  of  inflammatory 
conditions,  such  as  optic  neuritis.  Sudden  blindness  from  other  causes, 
such  as  migraine,  hysteria,  and  cerebral  disease  must  also  be  excluded. 

The  paroxysmal  failure  of  sight  may  occupy  a  few  minutes  only,  or 
last  several  hours,  and  may  obscure  a  part  or  the  whole  of  the  field  of 
vision.  It  may  affect  only  one  eye,  or  each  eye  at  different  times.  Occa- 
sionally even  both  eyes  are  involved  at  the  same  time.  Again,  it  may 
happen  that,  after  one  or  more  attacks  of  temporary  obscuration,  an 
attack  may  occur  which  ends  in  permanent  loss  of  sight.  Simultaneous 
failure  of  vision  in  both  eyes,  of  short  duration  in  one  eye,  but  permanent 
in  the  other,  has  also  been  observed — a  fact  which  tends  to  show  that 
the  temporary  and  permanent  attacks  of  blindness  are  of  the  same  nature. 
Some  of  the  patients  seem  to  have  been  in  very  good  health.  But  in 
most  some  form  of  cardiac  disease,  angemia,  or  angio-sclerosis  existed. 

The  general  symptoms  recorded  during  the  obscurations  consisted  in 
headache,  giddiness,  and  sometimes  vomiting  and  fainting.  Symptoms 
resembling  a  mild  form  of  Raynaud's  disease  were  noted  in  some  instances. 

It  is  very  probable  that  disease  of  the  retinal  arteries,  plus  alterations 
in  blood-pressure,  is  the  true  cause  of  these  temporary  obscurations  of  sight, 
although  some  believe  that  they  are  due  to  spasm  of  the  vessels.  Ophthal- 
moscopic examination  during  the  attacks  has  revealed  constriction  of  the 
retinal  vessels  and  appearances  similar  to  those  caused  by  occlusion  of 
the  central  artery. 

Thrombosis  of  the  Retinal  Vein  (Hsemorrhagic  Retinitis)  is 

seen  chiefly  in  old  people  with  atlieromatous  arteries,  cardiac  troubles, 
chronic  nephritis  or  diabetes.  Orbital  cellulitis,  due  to  erysipelas 
or  other  causes,  may  also  produce  it. 


328  DISEASES   OF   THE  EYE.  [chap.  xir. 

The  Ophthahnoscopic  Appearances  (Plate  VII.  Fig.  2)  consist  in 
extreme  engorgement  of  the  retinal  veins,  which  are  very  dark  in 
colour,  with  great  narrowing  of  the  arteries  ;  the  whole  fundus  is 
splashed  over  with  dark  haemorrhages  ;  the  optic  papilla,  which  at 
first  is  swollen  and  congested,  after  a  time  becomes  pale,  and  under- 
goes atrophy,  and  the  haemorrhages,  having  become  absorbed,  leave 
an  atrophied  retina  with  thready  arteries.  Secondary  thrombosis 
may  occur  in  the  central  artery,  and  then  a  white  cloudiness  of  the 
retina  will  appear  in  addition  to  signs  of  venous  thrombosis.  If  the 
thrombosis  be  confined  to  a  branch  of  the  central  vein,  the  ophthal- 
moscopic appearances  will  be  limited  to  the  corresponding  portion  of 
the  retina,  owing  to  the  absence  of  anastomosis  in  the  retinal  vessels. 

The  Prognosis  is  very  bad,  sight  becoming  permanently  damaged 
or  lost.     It  is  more  favourable  when  a  branch  only  is  thrombosed. 

Treatment  must  be  directed  to  the  general  condition.  In  many 
cases  secondary  glaucoma  comes  on  in  a  rather  acute  form,  and  it  is 
therefore  advisable  not  to  use  atropine,  in  case  it  might  precipitate 
an  attack.  A  highly  albuminous  exudation  takes  place,  which 
blocks  the  spaces  of  fontana  and  canal  of  Schlemm,  and  thus  the 
intra-ocular  tension  is  raised  ;  hence  the  angle  of  the  anterior 
chamber  is  often  open  in  these  cases  and  therefore  iridectomy  or 
trephining  is  not  of  much  avail,  and  enucleation  often  becomes 
necessary  for  the  relief  of  pain. 

Atrophies,  and  Degenerations,  of  the  Eetina. 

Retinitis  Pigmentosa  is  a  degenerative,  rather  than  an  inflam- 
matory, affection  of  the  retina.  It  is  extremely  chronic  in  its  pro- 
gress, coming  on  most  commonly  in  childhood,  and  often  resulting 
in  complete,  or  almost  complete,  blindness  in  advanced  life. 

Vision  is  much  affected,  but  the  symptom  chiefly  complained 
of  is  night-blindness,  due  rather  to  defective  power  of  retinal  adap- 
tation than  to  defective  light-sense.  The  field  of  vision,  moreover, 
becomes  gradually  contracted,  until  only  a  very  small  central 
portion  remains  ;  so  that,  although  the  patient  may  still  be  able 
to  read,  he  cannot  find  his  way  alone — a  function  for  which  the 
eccentric  parts  of  the  field  are  the  important  ones.  A  ring  scotoma 
in  the  field  of  vision  is  present  in  some  cases.  Finally,  the  last 
remaining  central  region  becomes  blind. 


PLATE    VI 

{To  face  page  328) 

The  pigment  is  arranged  in  a  circle  towards  the  periphery.  Note  the 
stellate  spots  and  the  absence  of  patches  of  atrophy,  and  also  the 
pigment  covering  the  vessels  (cf.  with  Plate  III.,  Fig.  2).  The  optic 
disc  is  yellowish,  the  retinal  vessels  thread-like,  and  the  chorioidal 
vessels  are  visible  all  over  the  fundus  owing  to  disappearance  of  the 
pigment -epithelium.  "" 


Plate  VI. 


Retinitis  Pigmentosa. 


CHAP.  XII.]  THE   RETINA.  329 


The  Ophthalmoscopic  Appearances  (Plate  VI.)  consist  in  a  pig- 
mentation of  the  nerve-fibre  layer  of  the  retina,  which  commences 
in  the  periphery,  but  not  at  its  extreme  limits,  and  in  the  course  of 
years  advances  towards  the  macula  lutea.  The  pigment  is  arranged 
in  stellate  spots,  of  which  the  processes  intercommunicate,  so 
that  the  appearance  reminds  one  of  a  drawing  of  the  Haversian 
system  of  bone.  Pigment  is  also  deposited  along  the  course  of  many 
of  the  vessels,  hiding  them  from  view.  The  degree  of  pigmentation 
varies  much,  and  in  some  cases  is  quite  absent,  and  the  diagnosis 
then  has  to  depend  upon  the  other  appearances  and  on  the  symptoms. 
The  papilla  is  of  a  greyish-yellow  colour,  never  white,  and  the  vessels 
are  very  small,  and  in  the  majority  of  cases  the  chorioidal  vessels 
are  visible  owing  to  disappearance  of  the  pigment  -  epithelium 
(Plate  YI.). 

The  chorioid  is  sometimes  slightly  affected,  irregularity  in  its 
pigmentation  being  observable.  At  the  posterior  pole  of  the 
crystalline  lens  there  is  often  a  star-shaped  opacity  (p.  272).  A  few 
thread-like  opacities  may  be  found  in  the  vitreous  humour. 

Pathology. — The  pigment  in  the  retina  is  beheved  to  wander  into  it 
from  the  pigment-epithehum  layer.  The  nervous  elements  of  the  retina 
become  atrophied  and  the  pigment  displaced.  The  other  pathological 
changes  in  the  retina  consist  in  hyperplasy  of  its  connective  tissue  elements, 
and  thickening  of  the  walls  of  the  vessels  at  the  expense  of  their  lumen. 
The  retina  also  becomes  adherent  to  the  chorioid. 

The  chorioidal  vessels,  too,  are  altered,  owing  to  endarteritis,  which 
causes  hypertrophy  of  their  coats,  with  more  or  less  obliteration  of  their 
lumen.  In  fact,  it  seems  probable  that  the  primary  seat  of  the  diseased 
process  is  in  the  chorioid ;  and  that  it  is  the  changes  in  it  which  cause 
the  pigment  from  the  pigment-epithelium  layer  to  wander  into  the  retina. 

Causes. — Retinitis  pigmentosa  often  affects  more  than  one 
member  of  a  family  and  is  hereditary  ;  and  the  patients,  too,  are 
frequently  defective  in  intelligence,  or  deaf  and  dumb.  Many  of 
them  are  the  offspring  of  marriages  of  consanguinity,  and  in  others 
an  inherited  syphilitic  taint  is  present,  while  in  others  no  cause  can 
be  assigned.  Other  congenital  defects,  supernumerary  digits,  etc., 
are  sometimes  present. 

Treatment  is  of  little  use.  At  best  one  may  stimulate  the  torpid 
retina  temporarily  by  hypodermic  injections  of  strychnia,  or  by  the 
continuous  current.     When  there  is  an  opacity  at  the  posterior 


330  DISEASES   OF   THE  EYE.  [chap.  xii. 


pole  of  the  lens,  although  it  may  be  of  only  slight  degree,  a  remark- 
able improvement  in  vision  can  be  effected  by  extraction  of  the 
lens. 

Retinitis  Punctata  Albsscens. — This  disease  commences  in  early  child- 
hood, or  is  perhaps  congenital.  It  often  occurs  in  more  than  one  member 
of  a  family,  and  the  parents  are  frequently  blood-relations.  The  main 
symptom  is  night-blindness  ;  in  good  daylight  central  vision  is  usually 
not  defective  to  any  marked  degree.  The  field  of  vision  is  contracted. 
Ophthalmoscopically,  the  fundus,  with  the  exception  of  the  macula  lutea 
and  its  immediate  neighbourhood,  is  sprinkled  over  with  innumerable 
small  white  dots,  which,  for  the  most  part,  are  free  from  any  pigmentary 
disturbance  in  their  neighbourhood.  In  some  cases,  towards  the  periphery 
of  the  fundus,  signs  of  chorioidal  atrophy  are  present,  or,  there  may  be 
pigment  in  the  retina  there.  The  retinal  vessels  and  the  optic  papilla 
are  unchanged.  It  is  thought  by  some  that  this  disease  is  related  to 
retinitis  pigmentosa. 

Treatment  is  of  no  avail. 

Gyrate  Atrophy  of  the  Retina  and  Chorioid. — This  disease,  which  is 
rare,  is  apt  to  occur  in  more  than  one  member  of  the  same  family,  and  in 
children  whose  parents  are  blood-relations.  The  first  symptom  appears 
in  childhood  as  night-blindness.  The  optic  papilla  is  atrophied,  as  in 
retinitis  pigmentosa,  and  atrophy  of  the  retina  is  shown  by  the  narrowing 
of  its  vessels.  The  characteristic  feature  is  the  peculiar  form  of  chorioidal 
atrophy.  In  a  zone  with  the  papilla  for  its  centre,  and  extending 
nearly  to  the  latter,  white  atrophic  dots  with  sharp  margins  form,  and 
gradually  increase  in  size,  until  they  become  confluent.  The  atrophy 
involves  both  the  pigment  epithelium  and  the  stroma  of  the  chorioid. 
The  papilla  is  finally  surrounded  by  a  broad  white  girdle,  from  which 
it  is  separated  by  a  band  of  normally  coloured  fundus.  The  edge 
of  the  girdle  towards  the  papilla  is  scalloped,  because  the  separate 
rounded  parts  of  which  it  is  composed  extend  backwards  in  varying 
distances,  while  the  remains  of  the  normal  fundus  project  forwards 
between  them  in  sharp  processes.  There  is  often,  as  in  retinitis  pigmentosa, 
a  star-shaped  posterior  polar  cataract.  In  addition  to  the  night-blind- 
ness, central  vision  is  much  lowered,  even  in  good  light,  and  the  field  of 
vision  is  much  contracted.  This  disease,  too,  is  closely  related  to  retinitis 
pigmentosa. 

Quinine  Amaurosis. — Quinine  in  large  doses,  and  very  occasion- 
ally in  small  doses,  is  liable  in  some  individuals  to  cause  amblyopia, 
which  may  come  on  almost  suddenly,  and  may  amount  to  absolute 
blindness,  accompanied  for  some  hours  or  days  by  great  deafness. 
This  absolute  blindness  is  rarely  more  than  temporary,  although 
it  may  last  for  some  weeks  ;  but,  in  severe  cases,  concentric  con- 
traction of  the  field  is  apt  to  remain  permanently,  with  or  without 


019111        .'lUoiOD  iU 


PLATE    VII. 
{To  face  page  330.) 

FiQ^  1. — Note  the  pallor  of  the  optic  disc,  the  thread-like  arteries,  the 
'  cherry-red  spot  '  at  the  macula  lutea,  and  the  surrounding  cloudiness 
of  the  retina. 

Fig.  2. — The  inferior  retinal  vein  is  engorged  and  tortuous,  and  darker 
in  colour.  There  is  slight  cloudy  oedema  of  the  retina,  and  numerous 
flame-shaped  and  blotchy  haemorrhages  ;  in  the  centre  of  one  large 
haemorrhage  are  some  white  spots  due  to  absorption,  or  to  fatty  de- 
generation. 


Plate  VII. 


Fig.   1.     Embolism  of  Central  Artery  of  Retina. 


Fig.  2.     Thrombosis  of  Inferior  Retinal  Vein. 


CHAP.  xiT.]  THE   RETINA.  331 


some  defect  of  central  vision.  In  a  serious  case  which  came  under 
our  notice,  the  colour  and  light-senses,  notwithstanding  the  con- 
tracted field  and  marked  seeming  optic  atrophy,  were  normal ;  but 
the  adaptation  of  the  retina,  as  shown  by  considerable  night- 
blindness,  was  defective. 

Yarr  finds  that  doses  of  sulphate  of  quinine  of  more  than  20 
grains  are  dangerous  to  the  sight,  and  that  more  than  40  grains 
should  not  be  given  in  twenty-four  hours.  During  the  early  stages, 
the  pupils  are  widely  dilated,  and  the  cornea  and  conjunctiva  are 
sometimes  anaesthetic. 

In  what  may  be  called  the  acute  stage,  the  Ophthalmoscopic 
Appearances  are  sometimes  normal,  but  pallor  of  the  optic  papilla, 
with  scarcity  and  smallness  of  the  retinal  vessels,  is  the  more  usual 
condition.  Where  the  case  is  chronic— the  fields  remaining  con- 
tracted, although  central  vision  has  improved — the  ophthalmoscope 
may  reveal  a  very  pale  optic  papilla  with  minimal  vessels. 

The  retinal  ischeemia  is  doubtless  the  immediate  Cause  of  the 
amblyopia,  and  is  the  result  of  diminished  heart's  action  and  lowered 
arterial  tension,  both  of  which  have  been  shown  to  be  produced 
by  large  doses  of  quinine.  Destruction  of  the  ganglion  cells  of  the 
retina  towards  its  periphery  has  been  found,  and  to  it  may  be 
referred  the  permanent  contraction  of  the  field  of  vision  in  some  cases. 

Treatment. — Cessation  of  the  use  of  quinine.  Digitalis  internally 
to  raise  the  arterial  tension,  nitro-giycerine,  hypodermic  injections 
of  strychnia,  and  general  tonic  treatment.  Nitrite  of  amyl  causes 
only  temporary  improvement  of  vision. 

Amaurosis  from  Filix  Mas. — In  the  rare  cases  of  this  kind  due  to  large 
doses  (3i  to  ij)  of  extract  of  male  fern,  the  blindness  is  usually  preceded 
by  headache,  vertigo,  tinnitus,  prostration,  diarrhoea,  and  coma  or  con- 
vulsions :  sometimes,  too,  by  pain  at  the  back  of  the  eye  and  on  movement. 
Ophthalmoscopically,  great  diminution  in  calibre  of  the  retinal  arteries 
with  congestion  of  the  veins,  and  extreme  oedema  of  the  retina,  seem  to 
be  the  initial  appearances,  followed  at  a  later  period  by  atrophy  of  the 
optic  nerve.     In  severe  cases  vision  does  not  return. 

Injury  of  the  Retina  by  Strong  Light. 

Blinding  of  the  Retina  by  Direct  Sunlight. — This  is  especially 
likely  to  occur  on  the  occasion  of  solar  eclipses,  by  observation 
without  proper  protection  of  the  eyes. 

Immediately   after  the   exposure,   the  patients  complain  of  a 


332  DISEASES   OF   THE   EYE.  [chap.  xii. 


dark  or  semi-blind  spot  in  the  centre  of  the  field  of  vision — a  posi- 
tive scotoma,  in  short,  which  may  even  be  absolute,  and  which 
interferes  with  vision  in  proportion  to  the  length  of  the  exposure. 
There  may  also  be  a  central  defect  for  colours,  which  may  extend 
over  a  larger  area.  A  peculiar  oscillation,  or  rotatory  movement, 
is  frequently  observed  by  the  patient  in  the  scotoma,  and  is  very 
persistent.  Objects  may  also  seem  twisted  or  otherwise  distorted 
(metamorphopsia) . 

The  Ophthalmoscopic  Appearances  may  be  normal,  but  as  a  rule 
some  changes  exist,  such  as  irregularity  or  indefiniteness  of  the  light 
reflex  at  the  macula,  with  reddish-brown  discoloration  around  the 
foveal  area,  or  a  minute  pale  orange  spot  near  the  fovea,  and,  especi- 
ally in  the  later  stages,  some  darkening  or  pigmentation.  When 
the  cases  are  not  severe,  improvement  in  vision  takes  place,  but 
complete  recovery  is  not  common.  Hitherto  no  case  in  which  the 
vision  had  been  reduced  to  less  than  J  has  regained  good  sight. 

Treatment. — Hypodermic  injections  of  strychnia,  the  constant 
galvanic  current,  dry  cupping  on  the  temple,  and  sub-conjunctival 
saline  injections,  afiord  the  best  chances  for  promoting  the  cure. 
Rest  and  dark  protection  glasses  are  important. 

Snow-Blindness. — Exposure  of  the  unprotected  eyes  for  a 
length  of  time  to  the  glare  from  an  extensive  surface  of  snow  pro- 
duces, in  some  persons,  a  peculiar  form  of  ophthalmia,  which  may 
be  followed  by  temporary  or  even  permanent  amblyopia.  Although 
this  condition  is  chiefly  an  affection  of  the  conjunctiva,  it  is  de- 
scribed here  in  order  to  contrast  it  with  the  effects  of  direct  sunlight 
and  electric  light. 

Snow-Blindness  begins  with  sensations  of  a  foreign  body  in 
the  eye,  photophobia,  blepharospasm,  and  lacrimation  ;  later  on 
chemosis,  with  small  opacities,  or  ulcers,  of  the  cornea,  comes  on. 
The  condition  passes  off  in  three  or  four  days  without  leaving  any 
pernianent  ill  results,  except  in  rare  cases,  when  there  may  be  some 
secondary  hyper.Tmia  of  the  retina.  It  is  held  to  be  the  ultra- 
violet-rays which  cause  snow-blindness. 

Treatment. — The  preventive  treatment  consists  in  the  wearing 
of  dark  smoked,  yellow,  or,  best  of  all,  euphos  glasses  when  travel- 
ling on  the  snow  ;  while,  for  the  ophthalmia  and  to  relieve  the  dis- 
tressing symptoms,  cold  applications  and  cocaine  with  adrenaline 
are  recommended. 


CHAP.  xti.J  THE   RETINA.  3^^ 


Effects  of  Electric  Light  on  the  Eyes. — The  degree  of  intensity 
of  electric  light  required  to  produce  injurious  effects  on  the  eye  is 
not  known  ;  but  no  bad  results  Jiave  been  observed  from  the 
ordinary  use  of  the  incandescent  electric  light,  for  reading,  writing, 
etc.  ;  on  the  contrary,  it  may  be  regarded  as  the  best  artificial  light 
for  these  and  other  domestic  uses.  It  has  a  greater  illuminating 
power,  produces  less  heat  and  no  products  of  combustion,  and 
hence  it  does  not  vitiate  the  atmosphere,  nor  tend  to  cause  con- 
junctival irritation.  The  electric  light  is  steadier  than  gas  ;  and, 
on  account  of  the  smaller  quantity  of  red  rays  it  contains,  it  more 
nearly  approaches  da3dight  than  does  gas,  unless  the  latter  be  used 
with  the  incandescent  mantle.  It  should,  however,  be  so  arranged 
for  use  that  the  rays  may  not  enter  the  eye  directly,  or  discomfort 
in  the  form  of  smarting,  burning,  and  headache  may  result,  by 
reason  of  its  being  rather  rich  in  ultra-violet  rays.  Two  groups 
of  symptoms  are  observed  from  the  action  of  strong  electric  light 
on  the  eyes  : — 

(«)  Electric  Ofhthalmia.  This  has  been  chiefly  seen  in  those 
employed  in  electric  welding  operations,  and  less  frequently  in 
electricians  who  use  strong  arc-light.  The  symptoms  begin  shortly 
after  exposure  to  the  light,  always  within  twenty-four  hours,  and 
are  the  same  as  those  present  in  snow-blindness  ;  the  lids  also  are 
swollen,  and  even  erythematous  at  times.  The  pupils  are  contracted. 
A  slight  muco-purulent  secretion  from  the  conjunctiva,  rich  in 
eosinophil  cells,  appears  after  the  subsidence  of  the  above  symptoms. 
Recovery  takes  place  in  a  few  days,  with  complete  restoration  of 
vision,  except  in  rare  cases. 

(6)  Blinding  of  the  Retina  by  Electric  Light.— This  is  the  same 
affection  as  the  blinding  of  the  retina  by  direct  sunlight.  The 
central  scotoma  may  persist  after  an  attack  of  electric  ophthalmia, 
or  may  occur  without  it.  The  injurious  action  of  the  electric  light 
on  the  eye  is  attributable  to  the  chemical  action  of  the  ultra-violet 
rays.  Widmark's  experiments  show  that  changes  can  be  produced 
in  the  retina  by  the  electric  light,  without  any  heat  coagulation. 
These  changes  consist  in  oedema,  with  more  or  less  destruction 
of  the  nervous  elements  of  the  retina — namely,  the  outer  layers, 
including  the  rods  and  cones,  and  the  inner  layer  of  nerve-fires. 

Treatment. — The  preventive  treatment  consists  in  the  use  of 
coloured  glasses.     Yellow  glass  has  been  recommended  by  Mak- 


f}34  DISEASES   OF   THE   EYE.  [chap.  xi±. 

lakoff,  and  the  new  euphos  glass,  a  peculiar  shade  of  yellow,  is 
also  in  use.  The  object  of  this  glass  is  to  cut  oft"  the  ultra-violet 
rays. 

For  further  effects  of  light  on  the  eyes,  see  also  glass- workers' 
cataract  and  erythropsia. 

Tumour  of  the  Retina. 

Glioma  of  the  Retina. — This  is  a  malignant  growth  and  is 
found  almost  exclusively  in  young  children,  or  may  even  be  con- 
genital, and  occasionally  occurs  in  several  children  of  the  same  family. 
It  is  sometimes  present  in  both  eyes.  Owing  to  the  age  of  the 
patients,  the  incipient  stages  of  the  disease  are  seldom  observed, 
for  they  are  unattended  by  pain  or  inflammation,  and  the  children 
are  not  brought  to  the  surgeon  until  the  parents  notice  that  the 
sight  is  very  defective,  or  until  they  see  the  white  appearance  in 
the  pupil. 

The  growth  commences  as  small,  \vhite,  disseminated  swellings 
in  the  retina,  usually  in  one  or  other  of  the  granular  layers,  more 
rarely  in  the  nerve-fibre  layer.  The  retina  is  apt  to  become  detached 
at  an  early  period  ;  but  there  are  exceptions  to  this,  especially  when 
the  disease  starts  from  the  nerve-fibre  layer.  Glioma  may  be  en- 
dophytic, growing  inwards  towards  vitreous  humour,  or  exophytic, 
growing  outwards  towards  chorioid.  In  the  early  stages  there  is 
no  iritis,  cyclitis,  or  opacity  of  the  vitreous  humour,  and  the  iris 
periphery  is  not  retracted — points  which  especially  enable  us  to 
distinguish  it  from  pseudo-glioma  (p.  298).  Secondary  glaucoma 
finally  comes  on.  The  optic  nerve  may  become  involved  at  an 
early  period  ;  but"  sooner  or  later  it  invariably  does  so,  leading  then 
by  extension  to  glioma  of  the  brain.  When  the  tumour  has  filled 
the  eyeball,  it  bursts  outwards,  usually  at  the  corneo-scl erotic 
margin,  and  then  grows  more  rapidly,  and  often  to  an  immense 
size,  as  a  fungus  ha3matodes.  The  orbital  tissues  become  involved, 
and  even  the  bony  walls  of  the  orbit ;  while  secondary  growths 
in  other  organs,  more  especially  in  the  liver,  are  not  rare. 

The  diagnosis  between  glioma  of  the  retina  and  tubercle  of  the 
chorioid  (p.  221),  when  the  latter  occurs  in  young  children,  is  some- 
times difficult  or  impossible  ;  but,  in  view  of  treatment,  it  is  not 
of  great  importance,  as  in  either  case  the  eye  must  be  enucleated. 


CHAP.  XII.]  TiaiS  RETINA.  335 


The  tumour  consists  of  closely  set  small  round  cells  with  a  large 
nucleus  and  little  protoplasm.  There  arc  numerous  vessels,  scanty 
intercellular  substance,  and  areas  of  degeneration. 

In  glioma  of  the  retina,  as  in  sarcoma  of  the  chorioid  (p.  220), 
phthisis  bulbi  with  regressive  metamorphosis  of  the  new  growth 
may  come  on,  and  give  the  appearance,  for  a  lengthened  time,  of 
a  cure  of  the  tumour.  But,  probably  invariably,  renewed  growth 
of  the  tumour  takes  place. 

Treatinent. — The  only  hope  of  saving  the  patient's  life  lies  in 
enucleation  at  an  early  stage,  or  before  the  optic  nerve  becomes 
diseased.  It  is  important  in  removing  the  eyeball,  as  in  every 
intra-ocular  growth,  to  divide  the  nerve  as  far  back  as  possible ; 
and,  if  the  orbital  tissues  be  already  diseased,  to  remove  all 
suspicious  portions  of  them.  Several  cases  in  which  there  was  no 
return  of  the  grow^th  have  been  observed,  even  after  removal  of  both 
eyes  ;  and  in  a  case  of  the  latter  kind  under  the  care  of  one  of  us, 
the  patient  continues  healthy  eight  years  after  removal  of  the  eyes. 

Tubercle  of  the  Retina. — Primary  tubercle  of  the  retina  is  exceedingly 
rare,  and  presents  the  appearance  of  a  more  or  less  extensive  and  slightly 
elevated  white  area,  at  the  posterior  pole  of  the  eye,  involving  the  optic 
disc  or  macula  lutea  or  both.  When  the  disease  occurs  in  a  young  child, 
the  diagnosis  from  glioma  of  the  retina  will  present  difficulty.  Or,  there 
is  in  the  region  of  the  posterior  pole  a  large  yellowish-white  mass  spreading 
out  in  all  directions  from  a  detached  and  non-translucent  area  of  retina, 
while  towards  the  periphery  there  are  multiple  haemorrhages  and  yellowish 
deposits  of  various  sizes  ;  the  optic  papilla  and  retinal  vessels  being  normal. 
More  commonly,  tubercular  disease  of  the  retina  is  secondary  to  tuber- 
culosis of  the  uveal  tract,  or  optic  nerve. 

Treatment. — Tuberculin  (p.  18-1). 


Paeasitic  Disease. 

Cysticercus  under  the  Retina. — The  cysticercus  of  the  tsenia  solium 
in  the  eye  is  very  rare.  Its  most  frequent  seat  is  between  the  retina  and 
chorioid,  where  it  is  recognised  with  the  ophthalmoscope  as  a  sharply 
defined  bluish-white  body,  with  bright  orange  margin.  At  one  point  of 
the  cyst  there  is  a  very  bright  spot,  which  corresponds  with  the  head  of 
the  entozoon.  Wave-like  motions  along  the  contour  of  the  cyst  should 
be  looked  for  to  corLfirm  the  diagnosis.  The  cysticercus  may  move  from 
its  original  position,  and  in  so  doing  cause  considerable  detachment  of  the 
retina.  Delicate  veil-like  opacities  are  apt  to  form  in  the  vitreous  humour, 
and  are  almost  characteristic  of  the  presence  of  cysticercus. 

The  entozoon  may  become  encapsuled  behind  the  retina  ;    or  it  may 


336  DISEASES   OF   THE  EYE.  [chap.  ±u. 

burst  into  the  vitreous  humour  (p.  312) ;  and  finally  chronic  irido-cyclitis, 
with  total  loss  of  sight  and  phthisis  buibi,  is  apt  to  come  on. 

Treatment. — There  is  no  authehnintic  which  will  act  upon  the  entozoon 
in  the  eye.  Removal  of  the  cyst  by  operation  is  the  only  means  by  which 
the  eye  can  be  saved  ;  and  this  measure  can  only  be  resorted  to  w^hen 
the  position  of  the  cysticercus  is  favourable — e.g.  when  it  is  close  to  the 
equator  of  the  eyeball.  In  such  cases,  by  a  well-placed  puncture  through 
the  sclerotic  and  chorioid,  the  entozoon  may  be  evacuated.  If  this  cannot 
be  accomplished,  the  eye  must  be  excised. 


Detachment  of  the  Retina. 

The  normal  retina  is  firmly  attached  at  the  optic  disc  and  at  the 
ora  serrata  only.  Between  these  it  adheres  merely  by  prolongations 
of  the  pigment  epithelium,  which  run  between  the  rods  and  cones, 
and  hence,  under  certain  conditions,  it  readily  becomes  detached 
or  separated  from  the  chorioid.  Even  when  there  is  '  total  detach- 
ment '  of  the  retina,  it  remains  adherent  at  the  optic  disc  and  ora 
serrata.  In  detachment  of  the  retina  the  space  between  retina 
and  chorioid  is  occupied  by  a  clear  serous  fluid.  It  is  not  usual  to 
employ  the  term,  when  it  is  a  solid  neoplasm  only  that  lies  between 
retina  and  chorioid. 

If  the  media  be  clear,  and  the  detached  portion  extensive,  the 
diagnosis  is  not  difficult. 

The  Ophthalmoscope  (Plate  V.  Fig.  2)  shows  a  greyish  reflex  from 
a  position  which  is  anterior  to  the  fundus  oculi,  and  to  the  surface 
from  which  the  greyish  reflex  is  obtained  a  wave-like  motion  is 
imparted  when  the  eyeball  is  moved.  Over  this  greyish  surface 
the  retinal  vessels  run,  and  they  serve  to  distinguish  a  detached 
retina  from  any  other  diseased  condition  with  a  somewhat  similar 
appearance.  The  vessels  seem  black,  not  red,  in  consequence  of 
absorption  of  the  light  reflected  back  from  the  fundus,  and  they 
are  hidden  from  view  here  and  there  in  the  folds  of  the  detached 
retina.  The  detachment  renders  these  parts  of  the  fundus  hyper- 
metropic. In  many  cases  a  rent  in  the  detached  retina,  usually 
towards  the  ora  serrata,  through  which  the  chorioid  can  be  dis- 
cerned, will  be  discovered.  In  some  cases  the  detached  part  retains 
its  transparency,  and  does  not  become  grey  or  opaque  ;  and  then 
it  is  the  reflexes  from  the  folds  of  the  detachment,  the  dark  retinal 
vessels,  and  the  fact  that  both  folds  and  vessels  lie  in  front  of  the 
true  fundus  oculi,  which  enable  the  diagnosis  to  be  made. 


CHAP.  XTi.]  THE   RETINA.  337 

The  detachment  may  commence  in  any  portion  of  the  fundus, 
but  most  commonly  does  so  above  ;  yet,  owing  to  gravitation  of 
the  fluid,  it  ultimately  settles  in  the  lower  half  of  the  fundus,  and 
hence  this  is  the  most  common  place  to  find  it,  the  part  first  detached 
having  become  replaced.  The  diagnosis  is  more  difficult  if  there  be 
but  little  fluid  behind  the  retina,  or  if  there  be  opacities  in  the  vitreous 
humour. 

Vision  is  affected  according  to  the  position  and  extent  of  tlie 
detachment.  Central  vision  may  be  quite  normal  if  the  macula 
lutea  and  its  immediate  neighbourhood  be  intact.  The  patients 
complain  of  distortion  of  objects  looked  at,  of  a  black  veil  or  curtain 
which  seems  to  hang  over  the  sight,  and  sometimes  of  black  floating 
spots  before  the  eye,  due  to  opacities  in  the  vitreous  humour.  These 
symptoms  often  come  on  suddenly  in  an  eye  which  has  hitherto 
had  good  sight. 

The  field  of  vision,  on  examination,  will  show  a  defect  which 
corresponds  with  the  position  of  the  detachment.  If,  for  example, 
the  detachment  be  below,  the  defect  will  be  in  the  upper  part  of 
the  field.  If  the  detachment  be  recent,  the  retina  not  having  yet 
undergone  secondary  changes,  and  if  the  quantity  of  subretinal 
fluid  be  not  great,  the  defect  in  the  field  may  only  amount  to  an 
indistinctness  of  vision  ;  while  later  on,  when — owing  to  derange- 
ment of  its  nutrition  from  its  being  separated  from  the  chorioidal 
capillaries — infiltration  and  degeneration  of  the  detached  part 
come  about,  fingers  may  not  be  counted  in  the  defective  area  of 
the  field.     Blue  blindness  is  sometimes  present. 

Should  the  detachment  become  complete,  little  more  than  mere 
power  of  perception  of  light  may  be  present.  Total  detachment 
is  followed  by  cataract,  and  often  by  iritis,  cyclitis,  and  phthisis 
bulbi.  The  detachment  may  remain  stationary,  and  may  not 
extend  to  the  whole  fundus,  or  the  retina  may  return  to  its  normal 
position  ;  but  this  latter  event  is  most  rare.  For  the  diagnosis  of 
detachment  of  the  retina  from  tumour  of  the  chorioid  see  p.  218. 

Causes. — Myopic  eyes — which  we  know  are  so  frequently  affected 
with  chorioiditis  and  disease  of  the  vitreous  humour — are  those 
most  subject  to  detachment  of  the  retina  (chap,  xvi.) ;  but  idiopathic 
detachment  occurs  also  in  eyes  which  are  apparently  healthy.  Blows 
upon  the  eye  may  produce  detachment,  the  retro-retinal  fluid  being 
serous  or  bloody  ;  and  some  punctured  w^ounds  of  the  sclerotic,  in 
22 


338  DISEASES   OF    THE   EYE.  [chap,  xii 

the  course  of  liealing,  by  dragging  on  the  retina,  give  rise  to  it. 
Chorioidal  tumours,  especially  those  situated  in  the  posterior  seg- 
ment of  the  fundus,  usually  cause  detachment  in  an  early  stage  of 
their  growth,  and  the  complication  renders  their  diagnosis  more 
difficult.  Other  causes  are  exudative  chorioiditis  and  rarely 
Inemorrhage. 

The  pathology  is  still  obscure.  Leber  observed  that,  in  non- traumatic 
detachment,  a  perforation  or  rent  in  the  detached  portion  is  very  fre- 
quently to  be  seen  with  the  ophthalmoscope,  and  holds  that  it  is  probably 
always  present,  although  sometimes,  from  being  hidden  behind  a  fold  of 
the  retina,  it  cannot  always  be  found.  From  this,  and  from  his  patho- 
logical investigations  and  experiments  upon  animals,  he  was  led  to  the 
opinion  that  the  detachment  was  due  to  shrinking  of  a  diseased  vitreous, 
which  first  became  slightly  separated  from  the  retina,  and  that  then — at 
some  place  where  the  retina  and  hyaloid  had  become  adherent  by  reason 
of  an  inflammatory  process — a  rent  was  produced  in  the  retina  by  the 
shrinking  process  in  the  vitreous.  He  concluded  that  through  this  rent 
the  fluid,  which  is  always  present  behind  the  vitreous  in  cases  of  detach- 
ment of  that  body,  makes  its  way  behind  the  retina,  and  separates  the 
latter  from  the  chorioid.  The  suddenness  with  which  detachment  often 
comes  on  is  accounted  for  by  this  theory.  Nordenson's  pathological 
researches  went  to  corroborate  this.  He  ascertained,  too,  that  disease 
of  the  ciliary  body  and  chorioid  is  the  primary  cause,  although  we  may 
not  be  always  able  to  detect  it  with  the  ophthalmoscope,  and  that  the 
pathological  change  in  the  vitreous  humour  consists  in  an  alteration  in 
its  connective  tissue  elements,  resulting  in  the  deleterious  shrinking. 

Raehlmann,  however,  from  the  results  of  experiments,  and  also  from 
clinical  observation,  concludes  that  detachment  of  the  retina  is  due  to 
exudation  from  the  chorioidal  vessels  of  a  fluid,  which  is  more  albuminous 
than  the  fluid  in  the  vitreous  humour.  Hence,  he  thinks,  diffusion  takes 
place  through  the  retina,  and  a  greater  quantity  of  the  less  albuminous 
vitreous  fluid  passes  through  the  retina,  thus  producing  and  increasing 
the  detachment.  Rupture  of  the  retina  is  not,  in  his  view,  a  necessary 
factor  in  the  causation,  but  it  may  occur  if  the  tension  behind  the  retina 
be  higher  than  that  in  front  of  it. 

Treatment. — The  dorsal  position  in  bed,  with  a  pressure  bandage 
on  the  eye,  and  diaphoretics  internally,  the  treatment  being  con- 
tinued for  from  four  to  six  weeks,  brings  about  reposition  of  the 
detachment  in  some  cases.  To  this  treatment  sub-conjunctival 
injections  of  a  5  to  10  per  cent,  saline  solution  may  be  added.  The 
method,  if  properly  carried  out,  is  trying  to  the  patient. 

Evacuation  of  the  subretinal  fluid  by  puncture  of  the  sclerotic 
is  employed.  The  instrument  used  resembles  a  broad  needle,  with 
blunt  edges,  which  is  entered  through  the  sclerotic  and  chorioid  at 


CHAP.  xiT.]  THE   RETINA.  339 

a  place  corresponding  with  the  position  of  the  detachment,  but  not 
so  deeply  as  to  reaT5h  the  retina,  lest  thereby  it  be  further  displaced. 
The  instrument  is  then  given  a  quarter  of  a  rotation,  to  make  the 
wound  gape,  so  as  to  admit  of  the  flowing  off  of  the  fluid.  If  possible, 
a  position  near  the  equator  of  the  globe,  and  between  two  recti 
muscles,  should  be  selected  for  the  operation.  Moreover,  the 
incision  should  lie  parallel  to  the  direction  of  the  muscles,  so  that 
the  chorioidal  vessels  may  be  injured  as  little  as  possible.  A  firm 
dressing  and  bandage  is  applied,  and  the  patient  kept  in  bed  for 
eight  or  ten  days.     For  the  most  part  the  cure  is  but  temporary. 

To  promote  adhesion  between  retina  and  chorioid.  Dor  touches 
the  sclerotic  corresponding  with  the  detachment  lightly  with  a  small 
cautery,  injects  rather  strong  (10  per  cent.)  solutions  of  common 
salt  under  the  conjunctiva,  and  keeps  the  patient  in  bed.  He 
reports  some  cures  by  this  method. 

The  cautery  may  be  combined  with  puncture,  or  the  puncture 
may  be  made  with  the  cautery. 

Other  operations  are  : — Transfixion  of  the  globe  through  the  de- 
tachment with  a  cataract  knife,  a  sort  of  double  puncture.  Excision 
of  a  portion  of  sclera  as  far  back  as  possible,  or  removal  of  a  disc 
with  the  trephine,  have  also  been  tried.  The  Prognosis  of  every 
case  of  detached  retina  is  bad,  spontaneous  cure  being  extremely 
rare,  and  cures  effected  by  any  one  or  by  any  combination  of  methods 
of  treatment  being  few  and  far  between  ;  while,  even  when  the 
retina  returns  to  its  place,  there  is  the  danger  of  a  recurrence  of  the 
detachment.  Moreover,  both  eyes  often  become  affected,  one  after 
the  other.  It  is  important  therefore  to  explain  the  prospects  of  the 
treatment  to  the  patient  before  it  is  commenced.  The  most  favour- 
able cases  are  those  due  to  chorioiditis,  the  most  unfavourable  those 
due  to  posterior  staphyloma. 

Traumatic  Affections  of  the  Retina. 

In  addition  to  detachment  and  rupture  of  the  retina,  the  under- 
mentioned conditions  occur  as  the  results  of  injuries. 

Traumatic  Anaesthesia  of  the  Retina.— A  blow  on  the  eye 
from  a  fist,  cork  from  a  bottle,  etc.,  is  liable  to  produce  considerable 
amblyopia,  with  concentric  contraction  of  the  field,  which  may 
continue  for  a  long  time,  while  the  Ophthalmoscopic  Appearances 


340  DISEASES   OF   THE   EYE.  [chap.  xii. 

are  normal.  Ultimately  these  cases  usually  recover,  an  event 
which  may  be  promoted  l)y  the  use  of  strychnine  hypodermically  ; 
but  very  defective  sight  sometimes  remains  perniiuieiitly. 

Commotio  Retinae,  or  Traumatic  (Edema  of  the  Retina,  is  the 

result  of  a  blow  upon  the  eye.  Immediately  after  the  blow  there 
is  marked  episcleral  injection,  and  the  pupil  can  be  dilated  but 
slowly  with  atropine.  Within  a  few  hours  after  the  accident  the 
Ophthalmoscope  reveals  a  white  cloudiness  (oedema)  of  a  portion 
of  the  retina,  usually  in  the  neighbourhood  of  the  optic  papilla 
and  macula,  but  sometimes  more  eccentrically ;  and  sometimes 
there  are  two  such  opaque  patches.  The  opacity  increases  in 
intensity,  and  spreads  somewhat.  The  retinal  vessels  remain 
normal ;  there  may  be  some  small  haemorrhages,  and  sometimes  the 
papilla  is  redder  than  normal.  These  appearances  completely 
disappear  in  the  course  of  a  few  days.  Vision  is  only  slightly 
affected,  and  recovers  as  the  retinal  changes  pass  off. 

'  Holes '  at  the  Macula  Lutea.  (Retinitis  atrophicans  centralis,  of 
Kuhnt). — Blows  on  the  eye  sometimes  give  rise  to  a  remarkable  lesion  at 
the  macula  lutea.  The  ophthalmoscopic  appearances  suggest  a  punched- 
out  hole,  generally  of  a  circular  or  oval  shape.  This  area  is  depressed 
below  the  level  of  the  surrounding  retina,  its  floor  is  of  a  deep  red  colour, 
and  its  margin  is  sharply  defined,  or  it  is  surrounded  by  a  light  cloud 
which  fades  off  into  the  retina.  On  the  floor  of  the  hole  and  arouiid  its 
margin  innumerable  very  fine  glittering  dots  are  present  in  many  cases. 
In  some  cases  there  is  a  shallow  detachment  of  the  retina,  but  in  the 
majority  of  them  there  is  none.  Contrary  to  what  would  be  expected, 
the  functions  of  the  macula  lutea,  although  diminished,  are  not  com- 
pletely lost,  and  an  absolute  central  scotoma  is  not  present  in  every  case. 
Consequently,  it  must  be  concluded  that,  notwithstanding  the  apparent 
serious  damage,  the  delicate  tissues  at  the  macula  lutea,  and  the  nerve- 
fibres  connecting  it  with  the  optic  nerve,  are  not  always  completely 
destroyed. 

Very  similar  appearances,  without  any  history  of  trauma,  have 
been  observed  occasionally  to  follow  iritis  or  irido-cyclitis.  They  have 
also  been  seen  in  the  eyes  of  elderly  people  the  subjects  of  arterio-sclerosis, 
and  in  albuminuric  retinitis,  retinitis  pigmentosa,  amaurotic  family  idiocy, 
after  perforating  injuries,  operations,  or  corneal  ulcers,  followed  by  in- 
flammation. The  pathogenesis  of  this  condition  has  not  been  clearly  made 
out.  (Edema,  or  cystic  degeneration  of  the  retina,  followed  by  destruction 
and  absorption  of  the  tissue  at  the  macula  is  probably  the  cause  of  these 
so-called  '  holes.' 


CHAPTER    XIII. 

DISEASES   OF   THE   OPTIC  NERVE. 

The  Optic  Nerve  may  be  affected,  directly  or  indirectly,  at  various 
parts  of  its  course,  from  the  optic  commissure  to  its  termination 
in  the  eyeball.  For  clinical  purposes  it  is  convenient  to  distinguish 
the  following  portions  of  the  nerve  ;  the  intra-cranial  portion,  the 
optic  canal  portion,  the  intra-orbital  portions  behind  and  in  front 
of  the  entrance  of  the  central  artery  of  the  retina  into  the  nerve, 
and  lastly  the  termination  of  the  nerve  in  the  eye,  known  as  the 
optic  papilla  or  optic  disc. 

Optic  Neuritis. — The  Ophthahnoscopic  Appearances  (Plate  VIII. 
Fig.  1)  of  inflammation  of  the  optic  nerve  within  the  eye,  vary  a  good 
deal  with  the  intensity  of  the  process.  Common  to  every  case  is 
hypersemia  and  swelling  of  the  papilla,  with  haziness  (so-called 
"  woolliness  ")  and  radial  striation  of  its  margins,  and  increase  in 
the  size  of  the  central  vein,  w^hile  the  central  artery  remains  of  normal 
dimensions,  or  is  contracted.  The  swelling  and  haziness  extend 
but  a  short  distance  into  the  surrounding  retina,  and  the  distension 
of  the  vein  is  also  not  continued  to  the  periphery  of  the  fundus.  In 
slight  cases,  these  appearances  may  barely  exceed  the  normal. 
They  first  appear  at  the  upper  and  lower  edges  of  the  disc  and  the 
inner  margin  becomes  affected  before  the  outer. 

In  extreme  instances,  the  disc  is  swollen  to  a  great  size,  and 
may  even  assume  quite  a  dome  shape,  while  the  veins  are  enor- 
mously distended  and  tortuous,  and  the  arteries  are  contracted  so 
as  to  become  barely  visible.  (Plate  VIII.)  In  some  cases  greyish 
striae  extend  from  the  papilla  into  the  surrounding  retina,  some 
flame-shaped  haemorrhages  are  present  on  or  near  the  papilla,  and, 
occasionally,  white  spots  in  the  retina,  and  a  stellate  arrangement 
of  small  white  dots  about  the  macula  lutea,  form  a  picture  which 

341 


342  DISEASES   OF   THE   EYE.  [chap.  xiii. 

cannot  be  distinguished  from  that  of  albuminuric  retinitis  (Plate  V. 
Fig.  1).  This  extreme  form  is  still  termed  Congestion  Papilla  or 
Choked  Disc.     It  is  also  known  as  Papilloedema. 

The  Vision,  even  in  cases  where  the  ophthalmoscopic  signs  are 
highly  developed,  is  frequently  normal ;  while,  again,  in  other,  and 
possibly  less  well-marked  cases,  it  may  be  reduced  to  perception 
of  light,  or  even  that  may  be  wanting.  When  due  to  cerebral 
tumour,  the  papilloedema  appears,  as  a  rule,  before  the  vision  becomes 
affected.  This  remarkable  disproportion  between  the  degree  of 
blindness  and  the  ophthalmoscopic  appearances  depends,  probably, 
on  the  extent  to  which  the  nervous  elements  of  the  optic  nerve 
are  pressed  on  or  altered,  and  this  cannot  be  gauged  by  the  ophthal- 
moscopic appearances. 

Sometimes  the  field  of  vision  is  normal,  while  again  it  is  con- 
centrically or  irregularly  contracted,  or  it  may  be  hemianopic. 
The  blind  spot  is  enlarged.  In  cases  of  choked  disc  the  field  for 
colours  is  often  reversed,  as  in  hysteria,  the  field  for  red  being 
wider  than  that  for  blue  (Fig.  12). 

Attacks  of  temporary  loss  of  sight  are  a  common  symptom  in 
cerebral  tumours  ;  they  may  occur  several  times  a  day,  and  each 
one  may  last  from  a  few  minutes  to  half-an-hour.  By  some  these 
attacks  are  held  to  be  due  to  cramp  of  the  retinal  vessels,  and.,  by 
others,  to  sudden  elevations  of  the  intra-cranial  pressure,  or  to 
pressure  of  the  infundibulum,  but  none  of  these  explanations  are 
satisfactory. 

Pathologically,  the  changes  in  the  papilla  consist  in  venous  hyper- 
£emia,  oedema,  hypertrophy  of  the  nerve-fibres,  infiltration  of  lymph 
cells,  and  development  of  connective  tissue.  Inflammatory  changes, 
although  less  pronounced,  are  also  present  in  the  trunk  of  the  nerve 
and  its  sheaths. 

Causes. — Inflammation  of  the  optic  nerve  is  most  commonly 
found  in  connection  with  coarse  encephalic  disease.  A  Cerebral 
Tumour  (including  syphiloma,  tubercle,  cyst,  and  abscess)  in  par- 
ticular is  the  most  common  cause,  and  is,  moreover,  usually  present 
when  the  papillitis  is  of  an  intense  type  (choked  disc).  Even  a  small 
tumour  situated  anywhere  in  the  brain  is  capable  of  producing  optic 
neuritis.  The  most  intense  papilloedema  is  seen  in  cases  of  cere- 
bellar tumour.  The  papilloedema,  except  in  very  rare  instances,  is 
bilateral,  and  it  is  one  of  the  general  symptoms  of  cerebral  tumour. 


PLATE    VIII 

{To  face  page  342) 

Fig.  1. — The  optic  disc  is  greatly  swollen  and  prominent  as  shown,  more 
especially,  by  the  enlarged  veins,  which  cm-ve  over  the  surface,  and 
which  are,  in  some  places,  lost  to  view  under  the  edge  of  the  swollen 
disc.  The  congestion  of  the  disc  is  somewhat  diminished  by  exuda- 
tion, and  several  flame-shaped  haemorrhages  are  present.  Tliis  is 
the  type  of  optic  neuritis  which  accompanies  intra-cranial  tumours. 

Fig.  2. — The  atrophy  here  has  followed  on  the  subsidence  of  optic  neuritis 
The  disc  is  very  white,  '  filled  in  '  in  the  centre  where  the  origin 
of  the  vessels  is  partly  hidden.  The  inner  margin  of  the  disc  is 
'  woolly.'  Note  the  white  lines  bordering  the  vessels,  due  to  peri- 
vasculitis.    Some  of  the  arteries  are  very  narrow. 

Fig.  3. — The  disc  is  white  and  sharply  defined,  and  the  lamina  cribrosa 
is  visible.  The  vessels  had  not  diminished  in  size  in  this  case,  although 
it  is  more  usual  to  find  them  much  reduced  in  calibre. 


Plate  VIII. 


L.VV. 

Fig.  1.  Choked  Disc. 


L.W. 

Fig.  2.     Consecutive  Atrophy  of  Optic  Nerve. 


L.W. 

Fig.  3.     Primary  Atrophy  of  Optic  Nerve. 


CHAP.  XIII.]  THE   OPTIC   NERVE.  343 

Hemianopsia  may  be  present  if  the  visual  centre  or  fibres  on  one  side 
be  involved.     Cerebral  cysts  do  not  often  cause  choked  disc. 

With  a  view  to  operation  it  would  be  important  to  know  whether 
papilloedema  has  any  locaHsing  vahie.  Can  it  afford  any  indication  of 
the  side  of  the  brain  in  which  the  tumour  or  lesion  is  situated  ?  The 
differences  of  opinion  which  prevail  with  regard  to  this  question  are  so 
great  that  it  is  difficult  to  give  a  satisfactory  answer,  but  this  much  may 
be  said  :  the  retinal  changes  (haemorrhages,  etc.)  present  along  with  the 
swelling  of  the  disc  have  no  localising  value,  and  the  same  applies  to  the 
choked  disc  itself  in  the  intracranial  complications  of  otitis  media,  with 
the  exception  perhaps  of  cerebral  abscess  ;  further  it  may  be  stated  that 
cerebral  abscesses  and  tumours  of  the  cerebellum  are  more  likely  to  be 
found  on  the  side  of  the  more  advanced  papilloedema  if  it  be  bilateral,  or 
on  the  side  of  the  papilloedema  if  it  be  unilateral. 

Exophthalmos  (apart  from  actual  invasion  of  the  orbit  by  a  growth) 
when  it  occurs  with  papilloedema,  is  more  marked  on  the  side  of  the  intra- 
cranial tumour,  or  is  present  on  that  side  alone. 

The  Connection  between  Congestion  Papilla  and  Intra-cranial 
Tumours  has  given  rise  to  much  discussion,  and  many  divergent 
views  are  still  held  on  the  subject.  In  these  cases  a  considerable 
exudation  of  fluid  usually  takes  place  into  the  cavity  of  the  third 
ventricle.  This,  along  with  the  new  growth,  increases  the  pressure 
within  the  cranial  cavity.  By  reason  of  this  increased  intra-cranial 
pressure,  the  sub-arachnoid  fluid  is  driven  into  the  sub-vaginal 
lymph-space  of  the  optic  nerve,  and  produces  that  dropsy  of  the 
sheath  which  is  found,  in  many  cases,  on  careful  post-mortem 
examination. 

It  may  be  that  the  reason  why  some  small  cerebral  tumours 
cause  papilloedema,  while  some  large  ones  do  not,  is  to  be  sought 
in  the  fact  that  the  former  may  happen  to  be  rapidly  growing 
tumours,  and  to  be  accompanied  by  much  ventricular  dropsy, 
while  the  larger  tumours  may  be  slow  in  growth,  and  attended  by 
but  little  dropsy  of  the  ventricles. 

Most  authors  now  believe  in  the  mechanical  theory,  according 
to  which  increased  intra-cranial  pressure  is  the  primary  and  essential 
cause  of  choked  disc  in  cases  of  intra-cranial  tumour,  and  that 
inflammatory  changes,  such  as  they  are,  are  only  secondary.  (Edema 
of  the  brain  substance  may  also  contribute  to  the  increased  pressure. 

Choked  disc  occurs  in  about  80  per  cent,  of  the  cases  of  intra- 
cranial tumour  ;  but  it  is  not  usually  one  of  the  very  earliest  signs, 
headache^  nausea,  etc.,  preceding  it  in  the  majority  of  cases.     In 


344  DISEASES   OF   THE   EYE.  [chap.  xiii. 

tumour  of  the  cerebellum  choked  disc  is  commonly  an  earlier 
symptom  than  it  is  in  tumour  of  the  cerebrum.  Tumours  of  the 
pons,  medulla,  and  corpus  callosum  are  those  in  which  it  is  most 
likely  to  be  a  late  symptom.  In  the  course  of  time,  unless  death 
intervenes,  the  swelling  of  the  discs,  and  other  primary  appearances, 
subside,  and  complete  atrophy  of  the  optic  nerves  results  (Plate 
VIII.  Fig  2)  ;  and  even  before  this  stage  is  reached  the  patient 
will  have  become  absolutely  and  permanently  blind. 

Treatment. — To  avert  blindness,  even  where  the  prospects  of  life 
are  not  for  long,  and  with  the  object  of  affording  relief  from  the 
racking  headache,  and  other  distressing  symptoms,  it  has  become  a 
recognised  practice,  to  reduce  the  intra-cranial  pressure  by  a  pallia- 
tive decompression  operation.  This  is  accomplished  by  trephining 
the  skull  and  opening  the  dura  mater.  It  should  be  done  as  early 
as  possible  in  the  case,  and  it  is  held  by  some  to  be  indicated  even 
before  choked  disc  appears,  if  the  symptom  of  recurring  attacks  of 
blindness  be  present.  When  there  are  no  localising  symptoms  the 
right  temporo-parietal  region  is  selected  as  the  site  of  operation. 
Some  surgeons  do  not  open  the  dura  mater  unless  the  symptoms  are 
not  relieved,  when  they  incise  it  at  a  later  stage.  After  operation 
the  papilloedema  subsides,  sometimes  very  rapidly. 

Causes. — Other  intra-cranial  causes  besides  tumours  may- give 
rise  to  papilloedema,  for  example  cerebral  abscess,  fractures  of  the 
skull,  intra-cranial  aneurisms,  cerebral  sinus  thrombosis,  subdural 
haemorrhage,  and  cranial  deformity  (Tower  skull). 

Tubercular  Meningitis  is  a  common  cause  of  optic  neuritis. 
Non-tubercular  meningitis  occasionally  gives  rise  to  it,  and  some- 
times, also,  cerebro-spinal  meningitis. 

Hydrocephalus. — Here  the  pathogenesis  is  probably  the  same  as 
in  the  foregoing  ;  but  the  occurrence  of  optic  neuritis  is  not  very 
common  with  the  hydrocephalus  of  children.  It  does  occur  with 
the  rarer  hydrocephalus  of  adults,  of  which  the  symptoms  may  be 
indistinguishable  from  those  of  intra-cranial  tumour. 

See  also  Diffuse  Sclerosis  of  the  Brain,  chap.  xiv. 

Tumours  of  the  Orbit. — How  these  growths  bring  about  papillitis 
is  still  unknown. 

Inflammatory  Processes  in  the  Orbit,  such  as  caries,  inflamma- 
tion of  the  retro-orbital  areolar  tissue,  erysipelas  of  the  head  and 
face  extending  to  the  orbital  tissues,  and  periostitis.     The  presence 


CHAP.  XIII.]  THE   OPTIC   NERVE.  345 

of  the  latter  may  often  be  recognised  by  pain  on  motion  of  the 
eyeball,  pain  in  the  eye  and  forehead,  and  especially  by  pain  on 
pressure  of  the  globe  backwards,  and  is  frequently  of  rheumatic 
origin.  Often  in  these  cases  one  eye  only  is  affected  ;  and,  although 
the  Ophthalmoscopic  Appearances  are  sometimes  very  slight,  yet 
vision  may  be  quite  lost  in  a  few  hours  or  days,  atrophy  of  the 
nerve  then  rapidly  setting  in.  Very  many  of  the  cases,  however, 
do  not  go  on  to  atrophy,  but  end  in  recovery  of  useful  vision. 

Disease  of  the  nasal  sinuses  usually  with,  but  it  may  be  without, 
secondary  involvement  of  the  orbit  sometimes  causes  optic  neuritis. 

Suppression  of  Menstruation. — If  during  the  menstrual  period 
the  flow  be  arrested  by  exposure  to  cold,  wet  feet,  etc.,  acute  optic 
neuritis  with  rapid  blindness  may  come  on.  Spontaneous  amenor- 
rhoea,  or  even  irregularity  of  menstruation,  and  the  climacteric  period 
are  liable  to  have  a  similar  but  more  chronic  result.  Nothing  is 
known  with  regard  to  the  connection  between  the  uterine  and  ocular 
disorder.  In  these  cases  the  Ophthalmoscopic  Appearances,  as 
well  as  the  blindness,  are  apt  to  be  extreme.  Treatment  should  be 
directed  chiefly  to  restoring,  when  possible,  the  normal  uterine 
functions.  Hot  foot-baths  and  Heurteloup's  leech  to  the  temples 
are  of  use. 

Chlorosis. — Here  the  optic  neuritis  is  due  to  the  disordered  state 
of  the  blood.  The  Ophthalmoscopic  Appearances  are  usually  slight, 
but  occasionally  they  are  of  extreme  degree,  and  resemble  choked 
disc.  These  latter  cases  may  be  taken  for  cerebral  tumour  by 
reason  of  concomitant  symptoms — headache,  vertigo,  vomiting, 
retraction  of  the  head,  stupor  or  delirium ;  and  convulsions.  Ocular 
paralysis  may  also  occur  especially  involving  the  sixth  nerves. 
These  symptoms  are  probably  due  to  intracranial  thrombosis.  The 
neuritis  yields  under  the  influence  of  iron  and  arsenic. 

Syphilis. — The  trunk  of  one  or  both  optic  nerves  may  be  the 
seat  of  specific  inflammation  in  connection  either  with  congenital 
or  with  acquired  syphilis,  but  this  primary  specific  optic  neuritis 
is  a  relatively  rare  disease.  In  cases  of  acquired  syphilis  it  makes 
its  appearance  in  from  six  months  to  two  years  after  the  primary 
infection.  The  Ophthalmoscopic  Appearances  may  be  normal 
(retro-bulbar  neuritis),  or  may  present  any  grade  of  neuritis,  even 
to  the  most  pronounced  papillitis.  In  the  latter  case  it  would  not 
be  possible  to  say  whether  the  papillitis  is  a  primary  one,  or  is  due 


346  DISEASES   OF   THE   EYE.  [chap.  xiii. 

to  a  syphilitic  gumma  within  the  cranium.  The  inflammation  often 
extends  as  far  up  as  the  chiasma.  The  Treatment  in  these  cases 
of  specific  papillitis  must  be  active  mercurialisation.  By  this  means, 
even  if  perception  of  light  be  lost  for  a  period  of  not  more  than 
eight  to  fourteen  days,  hopes  may  be  entertained  of  its  complete 
or  partial  recovery.  Cases  of  double  optic  neuritis  of  syphilitic 
origin  have  been  observed,  in  which  complete  recovery  took  place, 
the  papilla  returning  to  its  normal  condition.  But,  as  a  rule,  some 
optic  atrophy,  at  the  least,  with  slight  concentric  contraction  of  the 
field,  results.  The  prognosis  is  all  the  better  the  sooner  the  optic 
neuritis  follows  upon  the  primary  syphilitic  affection. 

Lead-Poisoning, — In  some  cases  of  lead-poisioning  optic  neuritis, 
not  to  be  distinguished  from  that  of  primary  cerebral  affections, 
is  found.  Sometimes  the  Ophthalmoscopic  Appearances  are  slight, 
and,  again,  quite  pronounced,  the  changes  extending  into  the  retina. 
They  sometimes  simulate  the  retinitis  of  Bright' s  disease  ;  and  in 
such  cases  renal  disease  is  likely  to  have  much  to  do  with  the  causa- 
tion of  the  retinitis.  Some  authorities,  who  have  good  opportunities 
for  forming  a  correct  opinion,  deny  the  existence  of  a  specific  lead 
neuritis,  and  hold  that  the  neuritic  affection  in  all  such  cases  is  to 
be  referred  to  albuminuria,  or  to  efiusion  into  the  ventricles  of  the 
brain  and  subarachnoid  space,  or  to  accompanying  suppression  of 
menstruation.  Occasionally  optic  atrophy  is  the  first  ophthal- 
moscopic appearance  seen  ;  but  it  is  probably  consecutive  to  retro- 
bulbar neuritis,  as  shown  by  white  striae  (perivasculitis)  along  the 
vessels.  The  Vision  is  often  much  affected,  and  it  is  stated  that 
sudden  complete  blindness,  or  hemianopsia,  in  connection  with  an 
intercurrent  attack  of  lead  colic  may  appear  and  pass  off  again. 
Consecutive  atrophy  is  liable  to  come  on,  and  then  vision  may  be 
seriously  and  permanently  damaged. 

As  headache,  vomiting,  and  convulsions  are  symptoms  of  the 
more  serious  cases  of  lead-poisoning,  it  is  evident  that  when  intense 
optic  neuritis  is  added,  the  diagnosis  between  this  disease  and 
cerebral  tumour  may  be  mistaken.  The  blue  line  on  the  gums, 
and  other  characteristic  signs  of  lead-poisoning,  will  prevent  such 
an  error.  The  Treatment  is  that  for  general  lead-poisoning,  or  for 
the  immediate  cause  of  the  neuritis. 

In  Peripheral  Neuritis  optic  neuritis  is  occasionally  found. 

Disseminated    Sclerosis. — In   these    cases   the    inflammation   is 


CHAP.   XIII.]  THE   OPTIC   NERVE.  347 

very  ephemeral,  and  rapidly  gives  place  to  atrophy.     UhthofE  states 
that  it  occurs  in  about  13  per  cent,  of  the  cases  of  this  disease. 

Tabes  Dorsalis. — A  few  cases  of  this  disease  are  published  in 
which  optic  neuritis  was  present.  It  is  probable  that  the  latter 
depended  on  co-existent  syphilitic  cerebral  disease,  rather  than  on 
the  spinal  disorder  as  such.  In  Acute  Myelitis,  inflammation  of  the 
optic  nerve  is  sometimes  seen,  so  that  optic  neuritis  with  paralytic 
phenomena  does  not  exclusively  indicate  cerebral  disease. 

Hereditary  and  Congenital  Predisposition. — The  disease  known  as 
Hereditary  Optic  Neuritis,  as  Hereditary  Optic  Atrophy,  and  as  Leber's 
Disease,  commences  with  sudden  and  marked  loss  of  sight,  the  vision  falling 
perhaps  to  finger  counting  at  1  to  4  m.  Both  eyes  are  always  attacked, 
with  an  interval  of  from  a  few  days  to  two  years.  The  fundus  is  at  first 
normal,  or  slight  optic  neuritis  is  present.  After  a  few  weeks  the  papilla 
becomes  pale,  especially  in  its  temporal  half,  and  gradually  the  typical 
appearance  of  optic  atrophy  is  developed.  Examination  of  the  field  of 
vision  shows  the  presence  of  a  relative  or  of  an  absolute  central  scotoma. 
The  periphery  of  the  field  is  normal,  or  but  slightly  contracted.  The 
disease  develops  as  a  rule  a  few  years  after  puberty — about  the  twentieth 
year.  The  course  and  conclusion  of  the  disease  is  not  the  same  in  every 
instance.  Most  commonly  the  acuteness  of  vision  and  the  central  scotoma 
remain  stationary,  but  in  some  cases  an  improvement,  falling  short  of 
complete  recovery  of  sight,  has  been  noted,  while  in  others  complete 
blindness  came  on.  In  the  same  family  the  course  of  blindness  is  apt 
to  be  the  same.  Grosser  derangements  of  the  nervous  system,  such  as 
epilepsy,  mental  derangements,  etc.,  do  not  commonly  accompany  this 
eye-disease,  but  the  lighter  forms,  as  migraine,  vertigo,  palpitation  of  the 
heart,  are  often  observed.  The  hereditary  transmission  usually  occurs 
through  the  female  members  of  the  family  to  their  male  children,  the 
females  themselves  being  rarely  affected,  while  several  or  all  of  the  sons 
may  be  attacked.  Treatment  is,  practically,  of  no  avail.  Mercury, 
iodide  of  potash,  strychnine,  and  galvanism  of  the  sympathetic  have  been 
employed.     This  disease  is  really  a  retrobulbar  neuritis   (see  below). 

Optic  Neuritis  also  occurs  occasionally  in  fevers  ;  it  has  been 
observed  in  Measles,  Scarlatina,  Typhoid,  and  Malaria.  It  may 
follow  Influenza,  causing  contraction  of  the  field  of  vision  or  central 
scotoma  which  usually  disappear,  but  may  lead  to  optic  atrophy. 

In  some  cases,  usually  with  high  degrees  of  hypermetropia,  the  papilla 
is  normally  red,  somewhat  prominent,  and  its  margins  are  indistinct  and 
striated.     The  condition  is  known  as  Pseudoneuritis  and  is  stationary. 

Retro-Bulbar  or  Axial  Optic  Neuritis.— This  is  ushered  in  by 
rapid,  although  never  sudden,  loss  of  sight  in  one  eye,  sometimes  in 


348 


DISEASES   OF   THE   EYE. 


[CHAP.    XIII. 


temp. 


both,  or  tliey  may  be  attacked  with  a  considerable  interval  between. 
Examination  of  the  field  of  vision  discovers  a  central  colour  scotoma, 
or  one  for  white  (Fig.  113),  which  is  often  absolute,  and  which  is  some- 
times surrounded  by  a  still  wider  scotoma  for  colours,  and  there  is 
impaired  pupil-reaction  to  light.  The  patient  sees  less  well  in  a  very 
bright  light.  At  the  commencement,  pain  in  the  orbit  is  complained 
of,  the  motions  of  the  eye  are  somewhat  painful,  and  there  is  pain  on 
moderate  pressure  of  the  globe  backwards  into  the  orbit.     Often 

at  first  there  are  no  oph- 
Left  Field  thalmoscopic      changes, 

but  after  a  time  marked 
optic  neuritis  shows  it- 
self, and  this  may  pass 
into  atrophy,  or  atrophy 
may  appear  without  any 
previous  neuritis  which 
can  be  discerned.  It  is 
rare  for  complete  and 
absolute  amaurosis  to 
result,  although  the  op- 
tic disc  remains  white. 
In  most  instances  the 
central  scotoma  dis- 
appears, and  almost  nor- 
mal vision  is  soon  re- 
stored ;  but  in  some  a 
more  or  less  well-marked 
central  scotoma,  with 
defective  sight,  remains. 
It  is  frequently  im- 
possible to  assign  a  cause 
for  this  affection.  Exposure  to  severe  blasts  of  cold  wind  on 
the  head,  rheumatism,  and  influenza  are  often  blamed  for  it. 
But  it  is  not  rarely  an  early  symptom  of  disseminated  sclerosis, 
and  from  this  point  of  view  it  must  be  regarded  with  suspicion 
when  it  occurs  in  persons  of  between  twenty  and  forty  years  of 
age.  It  is  also  found  associated  with  inflammatory  processes  in 
the  sphenoidal  or  ethmoidal  sinus.  (See  also  Toxic  Amblyopia, 
p.  349.) 


Fig.  1 1 3, — Case  of  Retro-hulhar  Neuritis  in 
Left  Eye.  Relative  central  scotoma  for  white. 
Central  V  =  finger  counting  at  1  metre. 
Movements  of  eye  somewhat  painful.  Pres- 
sure backwards  on  eyeball  caused  pain. 
Slight  cloudiness  of  margin  of  disc.  Caused 
by  chill  through  exposure  to  cold  fog  when 
heated.  Almost  complete  recovery  of  V.  after 
nine  months.  Some  pallor  of  disc  remained. 
Right  eye  normal  throughout. 


CHAP,  xni.]  THE   OPTIC   NERVE.  340 

Treatment. — Iodide  of  potassium  in  large  doses  and  salicylate 

of  soda.  • 

Optic  Neuritis  associated   with   Persistent  Cerebro-Spinal   Rhinorrhoea. — 

A  good  inany  cases  of  piu-sistciit  dropping  of  a  watery  fluid  from  the 
nostril  have  been  recorded,  and  in  a  considerable  proportion  of  thcni  the 
eyesight  was  much  affected,  owing  to  optic  neuritis  or  consecutive  atrophy. 
More  or  less  severe  cerebral  symptoms  are  usually  also  present,  such  as 
violent  headache,  epileptic  attacks,  vomiting,  stupidity,  drowsiness, 
unconsciousness,  delirium,  and  weakness  of  the  lower  extremities.  The 
severity  of  the  head  symptoms  varies  very  much  in  different  cases.  Head- 
ache is  the  most  constant  of  these  symptoms,  but  even  it  may  be  absent. 
In  one  case  there  was  loss  of  smell,  and  in  another  palpitation  of  the  heart 
with  prominence  of  the  eyes.  The  fluid  which  runs  from  the  nostrils  is 
identical  in  its  analysis  with  that  of  the  cerebro-spinal  fluid.  The  cerebral 
symptoms  are  usually  brought  on,  or  increased  in  violence,  if  the  fluid 
should  occasionally  cease  to  flow.  Leber's  case  proved  to  be  one  of 
internal  hydrocephalus,  and  the  others  were  probably  of  similar  nature. 
He  thinks  the  fluid  comes  from  the  third  ventricle  through  a  small  opening 
in  the  ethmoid  bone,  or  the  fluid  possibly  passed  from  the  sub-dural  space 
along  the  lymph-spaces  which  surround  the  olfactory  nerves. 

The  affection  usually  commences  in  early  adult  life,  and  no  rational 
treatment  has  been  suggested.  The  flow  may  cease  spontaneously  for 
periods  varying  from  a  few  hours  to  several  months.  In  some  cases  it 
ceased  altogether,  or  at  least  had  not  recurred  after  five  or  even  fourteen 
years.  Most  of  the  cases  were  lost  sight  of,  but  some  are  recorded  as  having 
died  of  meningitis. 

Toxic  Amblyopia  (Axial  Neuritis). — Sijmftoms. — The  defect  of 
vision  comes  on  rather  rapidly.  The  patients  often  complain  of  a 
shimmering  mist  which  covers  all  objects,  especially  in  a  bright  light, 
and  generally  state  they  can  see  better  in  the  dusk  than  in  broad 
daylight.  At  the  commencement  there  is  general  dimness  of  vision 
but  no  defect  in  the  field.  At  a  later  stage,  examination  of  the 
field  discovers  no  defect  for  a  white  object ;  but,  if  a  small  pale 
green  object  be  employed,  it  usually  will  be  ascertained  that,  at 
a  region  close  to  the  point  of  fixation,  the  colour  is  not  recognised, 
but  seems  grey  or  white  ;  pink  may  seem  blue,  and  red  may  appear 
brown  or  black.  This  is  a  central  colour-scotoma  (Fig.  16),  and 
when  it  is  very  small  it  is  easily  overlooked  in  the  examination, 
unless  a  very  small  test  object  be  used.  As  the  disease  advances, 
a  white  object  will  be  but  indistinctly  seen  in  the  scotoma  ;  and  in 
some  rare  cases  all  power  of  perception  within  its  area  may  be  lost, 
even  the  flame  of  a  candle  not  being  recognised.  The  scotoma  is 
usually  of  an  oval  shape,  with  its  long  axis  horizontal,  and  it  extends 


350 


DISEASES   OF   THE   EYE. 


[chap.  xiii. 


from  the  fixation  point  towards  the  blind-spot.  Occasionally  it  is 
of  much  larger  dimensions,  and  sometimes  surrounds  the  fixation 
point  (Fig.  114).  The  peripheral  boundaries  of  the  field  of  vision 
remain  normal,  both  for  colours  and  for  white. 

Even  when  the  scotoma  is  very  pronounced  it  remains  negative 
— i.e.  it  is  not  observed  by  the  patient  as  a  dark  spot  in  the  field, 
as  is  a  scotoma  due  to  disease  in  the  outer  retinal  layers.  The 
affection  is  almost  always  binocular,  and  as  a  rule  there  is  but  little 
difference  between  the  vision  of  the  two  eyes. 

The  Progress  of  the  disease  is  slow,  occupying  weeks  or  months. 


Fig.  114. — Case  of  Toxic  Amblyopia.  Central  (pericentric)  relative 
scotoma  for  white  in  each  eye.  V.  in  R.E.  fingers  at  2*0  m.  ;  in  L.E. 
fingers  at  5*5  m.  Pipe,  1  oz.  strong  tobacco  per  diem,  and  drank  much 
whisky.  Outei  third  of  each  disc  too  pale.  By  abstention  from  tobacco 
and  alcohol,  with  strychnine  and  phosphorus  internally,  ahiiost  complete 
recovery  in  four  months. 

Restoration  of  normal  vision  usually  takes  place  if  the  defect  of 
vision,  although  of  extreme  degree,  be  not  of  old  standing.  In 
the  latter  case  these  patients,  although  incapacitated  from  reading, 
writing,  and  other  fine  work,  do  not  lose  their  power  of  guiding 
themselves,  as  the  functions  of  the  periphery  of  the  field  are 
maintained. 

Causes. — With  but  few  exceptions  the  subjects  of  this  disease 
are  men,  and  the  most  common  cause  is  excess  in  the  use  of  alcohol, 
or  of  tobacco,  or  of  both.  The  kind  of  alcoholic  indulgence  most 
likely  to  develop  the  disease  is  the  frequent  drinking  of  small  doses 


CH.\P.  XIII.]  THE   OPTIC  NERVE.  351 

of  the  stimulant.  The  individual  who  often  gets  thoroughly  in- 
toxicated, and  between  times  drinks  but  little,  is  less  liable  to  con- 
tract central  amblyopia  than  he  who,  although  never  incapable 
of  transacting  his  business,  takes  many  half-glasses  of  whisky  or 
brandy  during  the  day.  Dyspepsia  and  loss  of  appetite  are  con- 
stantly present  in  these  cases.  Other  signs  of  chronic  alcoholism 
need  not  be  present,  but  one  often  sees  trembling  of  the  hand 
and  head,  sleeplessness,  and  even  delirium  tremens.  The  kind  of 
tobacco  most  likely,  when  used  in  excess,  to  give  rise  to  central 
amblyopia  is  shag  or  twist.  Other  kinds  of  pipe-tobacco  and 
cigars  may  cause  it,  but  we  have  not  known  of  a  case  due  to 
cigarette-  smoking. 

Excess  in  alcohol  is  usually  combined  with  excessive  smoking, 
usually  over  two  ounces  of  strong  tobacco  in  the  week  ;  but  cases  of 
pure  alcohol-amblyopia  certainly  do  occur — although  some  authors 
deny  it — as  well  as  pure  tobacco-amblyopia.  The  most  common 
age  for  tobacco-amblyopia  is  from  thirty-five  to  fifty — a  time  of 
life  when  men  do  well  to  give  up,  or  to  reduce  very  much,  their  use 
of  tobacco,  as  well  as  of  alcohol. 

Toxic  amblyopia  has  also  been  observed  in  diabetes,  syphilis, 
nasal  sinus  disease,  influenza,  and  some  other  febrile  affections,  and 
in  severe  burns  of  the  skin,  in  poisoning  from  bisulphide  of  carbon, 
largely  used  in  the  manufacture  of  india-rubber  ;  from  dinitro- 
benzol,  used  for  explosives  ;  and  in  poisoning  with  iodoform,  stra- 
monium, cannabis  indica,  opium,  salicylic  acid,  filix  mas,  arsenic, 
and  lead. 

The  Ophthahnoscopic  Appearances  in  the  beginning  are  usually 
quite  normal.  It  is  rarely  that  there  is  slight  hypersemia  of  the 
papilla  and  retinal  vessels  ;  or,  in  addition,  slight  indistinctness  of 
the  margins  of  the  papilla,  and  sometimes  white  striae  along  the 
vessels,  especially  before  they  leave  the  papilla.  All  the  primary 
appearances,  if  any  be  present,  soon  pass  away,  and  give  place  to 
a  greyish  whiteness  of  the  temporal  side  of  the  papilla,  while  the 
nasal  portion  remains  of  normal  appearance,  as  do  also  the  vessels. 
At  a  very  advanced  stage,  in  some  cases,  the  whole  papilla  presents 
the  appearance  of  white  atrophy. 

The  Pathological  Changes,  in  the  optic  nerve,  consist  of  an  in- 
terstitial neuritis  at  its  axis,  commencing  so  high  up  as  the  optic 
foramen,  and  gradually  leading  to  proliferation  of  connective  tissue 


352  DISEASES   OF   THE  EYE.  [chap.  xiii. 


and  to  secondary  descending  atrophy  of  one  bundle  of  fibres  in  the 
optic*  nerve.  These  are  the  papillo-mjicular  fibi'es  wliich  specially 
supply  the  region  of  the  macula  hitea,  and  which  are  exceedingly 
vulnerable  to  the  inlluence  of  certain  toxic  agents.  The  changes 
may  be  regarded  as  analogous  to  those  which  take  place  in  the 
liver  and  brain  as  the  result  of  chronic  alcoholism. 

Treatment  consists,  above  all,  in  total  abstinence  from  the  poison 
in  question  ;  partial  abstention  is  of  little  or  no  avail.  If  the 
patients  act  up  to  their  good  intentions  in  this  respect,  improve- 
ment rapidly  takes  place  in  most  cases  w4iich  are  not  too  far 
advanced  without  any  other  treatment ;  but  the  cure  may  be  pro- 
moted by  the  use  of  iodide  of  potassium  in  large  doses,  Heurteloup's 
artificial  leech  or  dry  cupping  to  the  temples,  hot  foot-baths,  and 
Turkish  baths.  Strychnine  hypodermically  (y\^  grain  daily)  in  the 
temple  is  often  of  use,  and  phosphorus  and  strychnine  may  be  given 
internally.  Whatever  remedy  be  used  internally,  care  should  be 
taken  that  it  does  not  produce  or  increase  dyspepsia  ;  and  it  may 
be  necessary  to  restrict  the  internal  medicine  for  a  time,  or  alto- 
gether, to  a  stomachic  tonic,  w4th  abundant  drinking  of  hot  water. 
Sleeplessness  should  be  combated  wath  sulphonal,  or  bromide  of 
potassium.  Treatment  may  have  to  be  continued  for  some  weeks, 
before  a  cure  can  be  noted. 

A  yet  more  serious  blindness  than  that  from  ethyl  alcohol  or  tobacco 
is  caused  by  drinking  methylated  spirit,  or  by  inhaling  its  fumes.  This 
toxic  amblyopia  is  much  more  common  in  the  United  States  than  else- 
where, for  a  peculiarly  dangerous  form  of  methylated  spirit  is  on  sale 
there  for  many  trade  purposes.  It  is  known  as  wood  alcohol,  or  Columbia 
spirit,  and  contains  95  per  cent,  of  methyl  alcohol.  The  symptoms  after 
a  debauch  have  been  weak  heart  action,  nausea,  sweating,  intense  head- 
ache, vertigo,  delirium,  and  coma.  Some  twenty-four  hours  later  dim- 
ness of  vision  in  each  eye  comes  on,  and  passes  rapidly  into  absolute 
blindness.  The  attack  of  blindness  is  accompanied  by  pain  on  movement 
of  the  eyes  and  on  pressure  of  the  eyeball  backwards,  symptoms  which 
would  tend  to  place  the  condition  in  the  category  of  retro-bulbar  neuritis. 
The  pupils  are  dilated,  and  the  liglit-reflex  is  absent.  A  characteristic 
feature  is  that  partial  restoration  of  vision  soon  takes  place,  to  be  followed, 
in  the  course  of  a  few  days  or  weeks,  by  more  or  less  complete  and  per- 
manent blindness.  In  the  early  stages  there  is  optic  neuritis,  which  is 
followed  by  optic  atrophy.  As  regards  the  field  of  vision,  there  is  an 
absolute  central  scotoma,  and,  moreover,  the  field  is  nearly  always  con- 
tracted. In  many  of  the  cases  death  has  occurred  within  a  few  hours 
after  the  poisonous  dose  has  been  taken.  There  also  have  been  recoveries 
of  sight  as  well  as  of  health. 


CHAP.   XIII.]  THE   OPTIC   NERVE.  353 

Atrophy  of  the  Optic  Nerve. — This  disease  may  be  secondary 
to  some  other  optic  nerve  or  retinal  affection,  or  it  may  be  a  pri- 
mary disease.  The  Vision  is  seriously  affected,  and  complete  blind- 
ness is  the  usual  result.  With  the  Ophthalmoscope  three  varieties  of 
atrophy  may  be  distinguished,  namely  : — 

(a)  Simple  Atrophy  (Plate  VIII.  Fig.  3),  which  is  most  often  a 
primary  affection  associated  with  disease  of  the  nervous  system 
such  as  locomotor  ataxy  or  disseminated  sclerosis,  but  may  be 
secondary  to  pressure  on  the  nerve  fibres  in  any  part  of  their  course 
below  the  external  geniculate  bodies.  The  optic  disc  loses  its  delicate 
pink  colour,  becomes  greyish  or  white,  its  margin  becomes  more 
defined,  it  becomes  flatter  or  even  slightly  cupped,  and  the  vessels 
in  some  cases  are  greatly  reduced  in  calibre.  Atrophy  of  this  type 
is  also  caused  by  retrobulbar  neuritis,  embolism  of  the  central 
artery  of  the  retina,  blindness  from  poisons  (quinine,  arsenic),  severe 
haemorrhages  from  stomach,  etc.  In  glaucoma  too  simple  atrophy 
occurs. 

(b)  In  Consecutive  Atrophy  following  optic  neuritis  (Plate  VIII. 
Fig.  2)  the  ophthalmoscopic  appearances  consist  in  a  white  or  greyish- 
white  papilla,  with  very  diminished  retinal  vessels  ;  along  the  sides 
of  the  vessels  are  white  lines,  which  sometimes  even  obscure  the 
vessels,  and  which  are  due  to  hypertrophy  of  their  coats.  The 
diminution  in  calibre  of  the  vessel  is  a  sign  of  neuritic  atrophy,  but 
is  not  always  present,  and  is  found  moreover  with  other  forms  of 
atrophy.  Other  signs  are  a  certain  opacity  of  the  papilla,  with 
filling  in  of  the  centre  of  the  disc  and  concealment  of  the  lamina 
cribrosa,  owing  to  development  of  connective  tissue.  The  veins 
are  generally  somewhat  enlarged  and  tortuous.  But  many  of 
these  signs  tend  to  pass  away,  and  after  a  time  it  may  not  be 
possible  to  distinguish  a  post-neuritic  from  a  primary  atrophy. 

When  the  optic  disc  begins  to  undergo  atrophic  changes,  the 
temporal  half  is  the  first  to  lose  its  colour  and  in  some  cases  the 
whiteness  remains  confined  to  the  outer  half  (toxic  amblyopia).  In 
making  a  diagnosis  of  atrophy  it  should  also  be  remembered  that 
the  temporal  side  of  the  disc,  even  in  the  normal  eye,  is  paler  than 
the  nasal  side.  In  the  aged  too  the  disc  does  not  present  the  pink 
transparent  appearance  seen  in  young  people. 

Symptoms. — In  the  first  two  forms  of  optic  atrophy  the  acuteness 
of  vision  is  lowered,  and  as  a  rule  the  field  of  vision  becomes  con- 
23 


354  DISEASES   OF    THE   EYE.  [chap.  xiii. 

tracted,  usually  more  at  the  nasal  than  at  the  temporal  side.  Sub- 
sequently the  temporal  side  of  the  field  becomes  contracted,  and 
finally  a  small  eccentric  portion  of  the  field  to  the  temporal  side 
may  be  all  that  remains,  or  even  this  may  disappear,  and  absolute 
amaurosis  result.  The  colour-vision  is  always  much  affected.  The 
light-sense  is  affected,  so  that  there  is  diminished  sensibility  for 
differences  of  illumination ;  while,  in  chorioido-retinal  diseases, 
there  is  defect  in  the  quantitative  perception  of  light,  the  minimum 
quantity  being  larger  than  normal. 

(c)  Chorioido- Retinal  Atrophy  of  the  Optic  Nerve  {Waxy  Disc) 
is  due  to  syphilitic  retinitis,  retinitis  pigmentosa  (Plate  VI.),  and 
chorioido-retinitis. — The  vessels  here  are  much  attenuated,  and  the 
altered  colour  of  the  optic  disc  is  a  dull  or  dirty  yellow,  rather 
than  white  or  grey. 

The  two  last  varieties  of  atrophy  are  of  course  secondary  to 
disease  within  the  eye.  Simple  atrophy  may  also  be  secondary,  but 
when  it  is  so,  it  is  due  to  pressure  on  the  nerve  fibres  outside  the  eye 
and  may  be  brought  about  by  a  tumour  anywhere  in  the  course  of 
the  nerve,  by  inflammatory  exudations,  by  a  splinter  of  bone  in 
cases  of  fracture  of  the  skull,  and,  also,  by  pressure  upon  the  chiasma 
by  the  floor  of  the  distended  third  ventricle  in  cases  of  internal 
hydrocephalus. 

Primary  Optic  Atrophy  is  often  found  associated  with  : — 

Disease  of  the  Spinal  Cord  {Spinal  Amaurosis),  especially  loco- 
motor ataxy.  Optic  atrophy  occurs  in  10  to  15  per  cent,  of  the 
cases  of  locomotor  ataxy  and  is  often  an  early  symptom  ;  but, 
again,  it  may  not  come  on  until  the  affection  of  the  gait  is  well 
pronounced,  while  in  other  cases  it  is  not  present  at  any  stage. 
It  is  a  remarkable  and  important  fact,  first  pointed  out  by  Benedikt 
of  Vienna,  that  there  is  an  antagonism  between  atrophy  of  the 
optic  disc  and  the  other  symptoms  of  tabes  dorsalis ;  that  is 
to  say,  it  is  rarely  that  a  tabetic  patient,  in  whom  optic  atrophy 
comes  on  in  an  early  stage  of  his  disease,  becomes  ataxic ; 
and  frequently,  in  these  cases,  when  the  blindness  has  advanced, 
the  disease  becomes  stationary.  But  if  amaurosis  do  not  come 
on  until  the  ataxy  is  well  developed,  no  improvement  in  the  latter 
is  likely  to  be  noted.  Atrophy  of  the  optic  nerve  also  occurs  in 
cases  of  infantile  tabes. 

More  rarely,  atrophy  is  found  with  disseminated  sclerosis,  and 


crrAP.  XIII. 


THE    OPTIC    NERVE. 


355 


lateral  sclerosis  of  the  spinal  cord.  In  general  paralysis  of  the  insane, 
although  spinal  disease  is  not  always  present,  atrophy  of  the  papilla 
frequently  occurs. 

It  is  probable  that  the  disease  commences  at,  or  close  to,  the 
papilla  in  spinal  cases. 

Symptoms. — Central  vision  is  affected  at  an  early  stage  in  the 
disease,  and  eccentric  contraction  of  the  field  (Fig.  115)  usually 
appears  at  the  same  time.  The  contraction  may  be  concentric,  or 
it   may  be   more   marked   in   one   direction   than   another.      This 


Left  Field 


Right  Field 


Fig.  115. — Case  of  Locomotor  Ataxy.  Atrophy  of  each  optic  nerve 
R.E.  Marked  contraction  of  field — absolute  defect  for  white.  No  colour 
perception  in  remaining  portion  of  field.  Central  V  =  fingers  at  3*0  m. 
Very  white  optic  disc.  Became  quite  blind  five  months  later.  L.E.  Only 
slight  loss  in  periphery  of  field.     Fields  for  colour  irregularly  contracted. 

Outer  boundary  for  red  ,  for  blue .      Central  V  =  6/12.    White  optic 

disc.     Became  quite  blind  a  year  later. 

concentric  contraction  advances  gradually  towards  the  centre  of 
the  field  from  every  side,  until  it  finally  engulfs  the  fixation  point. 

Occasionally  the  affection  begins  as  a  central  scotoma,  accom- 
panied by  eccentric  defects  of  the  field.  Sometimes  also  defects  of  a 
hemianopic  or  sector-like  type  occur.  Colour-blindness  is  an  almost 
constant  symptom.  As  a  rule  absolute  blindness  is  brought  about 
in  the  course  of  a  year  or  two,  or  it  may  come  on  more  rapidly. 

It  is  doubtful  whether  Primary  Optic  Atrophy  of  the  progressive 
form  just  described  can  occur,  as  a  purely  local  disease,  without 
any  other  defect  in  the  system.     These  cases  if  followed  up  wo  aid 


356  DISEASES    OF    THE    EYE.  [chap.  xiii. 

probably  be  found  to  develop  some  form  of  disease  of  the  nervous 
system. 

As  the  result  of  Poisoning  with  Organic  Preparations  of  Arsenic. — These 
preparations  have  come  much  into  use  far  the  treatment  of  sleeping 
sickness  and  of  many  other  diseases  caused  by  protozoa,  but  unfortunately 
they  are  liable  to  give  rise  to  optic  atrophy  and  complete  blindness. 
Many  cases  of  blindness  have  been  recorded  from  the  use  of  atoxyl,  and 
arsacetin  has  also  caused  it.  No  case  of  blindness  from  the  use  of  salvarsan 
has  been  recorded.  The  accident  cannot  be  avoided,  for  it  depends  not 
so  much  on  the  size  of  the  dose  as  upon  individual  predisposition.  But 
it  seems  to  be  less  dangerous  to  give  one  large  dose  than  small  repeated 
doses.  It  may  be  that  the  blindness  caused  by  atoxyl  has  been  due  to 
the  methyl  alcohol  used  in  its  preparation,  rather  than  to  the  arsenic  ; 
and  we  understand  that  for  this  reason  Professor  Ehrlich  now  no  longer 
uses  methyl  alcohol  for  this  purpose.  When  atrophy  of  the  optic  nerve 
once  sets  in,  discontinuance  of  the  use  of  the  preparation  does  not  avail 
to  arrest  the  progress  of  the  blindness.  The  features  of  this  optic 
atrophy  are  : — Onset  with  haziness  and  scintillation,  and  progressive 
contraction  of  the  field  of  vision,  especially  on  the  nasal  side.  Central 
vision  remains  good  until  the  field  has  become  very  small,  and  in  the 
course  of  a  few  months  complete  loss  of  sight  ensues.  The  optic  nerve 
is  pale  and  sharply  defined.     The  vessels  are  much  reduced  in  size. 

Poisoning  by  the  inorganic  arsenic  preparations  does  not  cause  optic 
atrophy  and  amaurosis.  The  impairment  of  vision  is  only  slight,  there 
is  no  contraction  of  the  field,  but  a  central  colour-scotoma  is  present. 
The  ophthalmoscope  may  show  some  pallor  of  the  temporal  half  of  the 
optic  disc.  Discontinuance  of  the  drug  is  followed  by  recovery  of  sight, 
and  no  case  of  total  blindness  has  been  recorded.  The  inorganic  arsenic 
preparations  cause  conjunctivitis  and  oedema  of  the  ej^elids,  while  the 
organic  preparat^ions  do  not  do  so. 

Treatment. — In  neuritic  atrophy,  so  long  as  there  are  signs  of 
active  inflammation,  antiphlogistic  measures — Heurteloup's  leech 
to  the  temple,  hot  foot-baths,  rest  of  body  and  mind,  dark  room, 
iodide  of  potassium,  and,  especially,  mercury  internally,  when  other- 
wise admissible — are  to  be  adopted.  At  a  later  period,  hypodermic 
injections  of  strychnia  {^-^  gr.,  increased  gradually  to  ttV  or  ^^  gr. 
once  a  day)  and  galvanism  may  be  tried.  Hypodermic  injections 
of  antipyrin  (about  7|  grains  every  second  day)  have  been  given 
with  some  benefit  in  these  cases. 

In  spinal  amaurosis,  and  in  optic  atrophy  occurring  as  a  local 
disease,  strychnia  hypodermically  and  the  galvanic  current  sometimes 
improve  vision  for  a  time.     Phosphorus  internally  may  be  given. 

The  treatment  for  optic  atrophy,  due  to  other  causes,  is  to 
be  directed  to  the  primary  disease. 


OHAt.  XIII.  1  THE   OPTIC  NERVE.  357 


The  Prognosis  is  very  serious  ;  for,  although  every  therapeutic 
measure  may  have  been  employed,  amaurosis  is  the  ultimate  result 
as  a  rule.  Cases  of  primary  atrophy  due  to  poisoning  by  organic 
arsenic  preparations  are  hopeless  from  the  beginning. 

Hereditary  Of  tic  Atrofhy  (Leber's  Disease),  see  p.  347. 

Tumours  of  the  Optic  Nerve  will  be  treated  of  in  chap.  xx. 

Hyaline  Outgrowths  from  the  optic  papilla,  at  its  edge  or  centre,  are 
occasionally  met  with.  Seen  with  the  ophthalmoscope,  they  present  the 
appearances  of  small  bluish-grey  semi- translucent  nodules.  Those  which 
appear  at  the  edge  of  the  disc  only  are  of  the  same  nature  as  the  "  colloid 
bodies  "  which  occur  in  guttate  chorioiditis  (p.  191).  In  many  instances 
retinitis  pigmentosa  is  also  present.  These  outgrowths  do  not  always 
of  themselves  cause  a  defect  of  sight,  and  rarely  cause  serious  blindness. 

Treatment  is  of  no  avail. 

Injuries  of  the  Optic  Nerve. — In  addition  to  those  injuries 
which  result  from  direct  violence  with  sharp  instruments,  etc., 
entering  the  orbit,  the  optic  nerve  may  be  injured  by  falls  on  the 
head.  Fractures  of  the  base  of  the  skull  frequently  involve  injury 
to  the  optic  nerve.  But  even  where  no  fracture  occurs,  blindness 
with  atrophy  of  the  optic  nerve,  usually  only  in  one  eye,  may  follow 
a  blow,  or  fall,  on  the  head ;  and  in  these  cases  concussion  of  the 
nerve  at  its  passage  through  the  optic  foramen,  or  fracture  of 
the  optic  foramen,  or  an  extravasation  of  blood  in  the  sheath  of  the 
nerve,  is  probably  the  immediate  cause  of  the  atrophy. 

Haemorrhages  from  the  Stomach,  Bowels,  or  Uterus  are  capable  of  giving 
rise  to  serious  and  incurable  blindness. 

Blindness  during  or  immediately  after  a  severe  haemorrhage  is  prob- 
ably due  to  insufficient  blood-supply  to  the  nerve-centres  and  retina, 
accompanying  general  exhaustion  of  the  system.  For  such  cases  the 
prognosis  is  favourable. 

But  there  is  another  class  of  cases  of  very  much  more  serious  import. 
Fortunately,  they  are  rare.  In  these  the  defect  of  vision  does  not  come 
on  until  from  two  to  fourteen  days  after  the  haemorrhage,  when  the  general 
system  is  recovering.  Even  comparatively  slight  haemorrhages,  w^hich 
caused  no  marked  anaemia,  are  said  to  have  been  followed  by  blindness. 
The  pathogenesis  of  these  cases  is  not  yet  clearly  made  out.  Leber 
inclines  to  the  belief  that  the  blindness  here  is  due  to  an  extravasation 
of  blood  at  the  base  of  the  skull,  and  into  the  sheath  of  the  optic  nerve  ; 
but,  even  then,  the  relationship  between  this  and  the  stomachic  or  uterine 
haemorrhage  is  not  rendered  clearer.  Papillitis  has  been  several  times 
noted  with  the  ophthalmoscope  ;  and  this  circumstance  makes  it  probable 
that  neuritis  is   the   immediate  cause  of  blindness — even  in  those  cases 


358  DISEASES    OF    THE   EYE.  [chap.   xiii. 


which  show  no  ophthahiioscopic  sign  of  it — and  hydraemia  may  possibly 
be  the  influence  which  calls  forth  the  neuritis. 

The  Defect  of  Vision  may  be  but  slight,  or  it  may  amount  to  absolute 
amaurosis.  Both  eyes  are  usually  affected  in  equal  degree.  But  cases 
have  been  observed  in  which  one  eye  was  completely  amaurotic,  while 
the  vision  of  the  other  eye  was  quite  normal  ;  and  such  cases  prove  that 
the  lesion  is  peripheral — in  fact,  that  it  lies  on  the  distal  side  of  the  optic 
commissure.  The  field  of  vision  is  frequently  contracted,  either  concen- 
trically or  segmentally  ;  and,  even  when  central  vision  recovers,  the  field 
may  remain  contracted.  The  presence  of  central  scotoma  has  also  been 
observed  in  some  cases. 

The  Ophthalmoscopic  Appearances  which  are  present  immediately  on 
the  occurrence  of  the  blindness  have  not  as  yet  been  observed.  A  few 
weeks  later  they  are  different  in  different  cases.  They  have  been  found 
at  this  period  normal  ;  or  presenting  slight  paleness  of  the  papilla  and 
contraction  of  the  arteries  ;  or  there  was  marked  paleness  of  the  papilla, 
and  the  arteries  were  extremely  contracted,  with  slight  distension  of 
the  veins  ;  or  paleness  of  the  papilla  was  present,  but  its  margins  were 
indistinct,  and  the  surrounding  retina  somewhat  swollen,  while  the  retinal 
vessels  were  normal.  Small  haemorrhages  have  repeatedly  been  seen  in 
the  neighbourhood  of  the  papilla.  At  later  periods  well-marked  optic 
atrophy  is  frequently  observed. 

Prognosis. — If  in  the  beginning  the  defect  of  vision  be  merely  amblyopia, 
and  not  complete  blindness,  liopes  may  be  entertained  of  marked  improve- 
ment, or  of  complete  recovery.  But  Mooren  saw  slight  amblyopia  pass 
into  permanent  amaurosis. 

Haemorrhages  from  the  stomach  are  those  which  are  followed  by  the 
most  complete  and  permanent  blindness,  while  uterine  haemorrhages  are 
more  commonly  followed  by  less  serious  degrees  of   blindness. 

The  Treatment  must  consist  of  internal  remedies  calculated  to  correct 
the  general  anaemia,  such  as  iron,  beef-tea,  and  meat  extracts,  wine,  etc. 
Strychnine  hypodermically,   to  stimulate  the  nerve,   may   be  employed. 

Glycosuric  Amblyopia.— In  addition  to  the  retinal  affections 
dependent  upon  diabetes  (p.  318),  we  recognise  the  occasional  oc- 
currence in  that  disease  of  defects  of  vision  which  are  referred  to 
disorder  of  the  optic  nerve,  and  which  are  not  always  accompanied 
by  ophthalmoscopic  changes.  These  defects  of  vision  are  found 
in  the  form  of  (1)  Central  Toxic  Amblyopia  (p.  349),  or,  in  slighter 
cases,  as  amblyopia  without  central  scotoma.  Occasionally,  higher 
degrees  of  amblyopia  with  concentric  contraction  of  the  field  of 
vision,  and  yet  negative  ophthalmoscopic  appearances,  are  present. 
(2)  Atrophy  of  the  optic  nerve.  This  may  appear  in  the  usual  form 
as  progressive  blindness,  with  concentric  contraction  of  the  field 
of  vision  ;  or  it  may  come  on  after  the  slighter  form  of  amblyopia 
has  existed  for  some  time.     (3)  Hemianopsia  and  colour-blindness. 


OHAP.  XIII.  i  THE    OPTIC   NERVE.  ^50 


It  is  probable  that  these  apparently  different  kinds  of  blindness 
depend  upon  similar  pathological  processes,  and  merely  indicate 
degrees  of  the  latter.  In  what  these  processes  consist  is  still  un- 
known ;  but  the  tendency  to  haemorrhages  in  the  retina  in  diabetes 
makes  it  likely,  that  haemorrhages  in  the  optic  nerve  are  sometimes 
the  source  of  the  amblyopia  in  question  ;  while  the  cases  with 
central  scotoma  are  no  doubt  due  to  axial  neuritis,  similarly  as 
in  alcohol  and  tobacco  amblyopia. 

Amblyopia  is  sometimes  the  earliest  symptom  of  diabetes  ; 
and,  consequently,  it  is  of  the  utmost  importance  to  examine  the 
urine  for  sugar  in  every  case  of  amblyopia  where  the  ophthalmo- 
scopic appearances  are  negative,  or  where  the  only  abnormality  is 
atrophy  of  the  optic  papilla. 

The  Treatment  indicated  is  solely  that  for  the  general  disease,  and 
the  prognosis  for  vision  depends  upon  the  amenability  of  the  latter 
to  treatment,  and  upon  the  extent  to  which  organic  changes  in 
the  optic  nerve  have  advanced. 


CHAPTER  XIV. 

Part  I. — Ocular  Diseases  and  Symptoms  liable  to  accompany  Focal 

Disease  of  the  Brain. 
Part  II. — Ocular   Diseases    and    Symptoms    liable    to    accompany 

Diffuse  Organic  Diseases  of  the  Brain. 
Part  III. — Ocular    Diseases    and    Symptoms    liable    to    accompany 

Diseases  and  Injuries  of  the  Spinal  Cord. 
Part  IV. — Nervous  Amblyopia,  or  Asthenopia. 
Part  V. — Various  Forms  of  Amblyopia. 

Part  I. 

OCULAR  DISEASES  AND  SYMPTOMS  LIABLE  TO  ACCOMPANY 
FOCAL   DISEASE   OF   THE   BRAIN. 

Hemianopsia  [ri^ic-v^,  half ;  d,  friv. ;  wi//,  the  eye). — This  symp- 
tom consists  in  a  loss  of  sight  in  one-half  of  the  field  of  vision — 
usually  of  each  eye — consequent  upon  a  lesion  either  at  the  cortical 
centre  for  vision,  or  at  the  optic  commissure  (chiasma),  or  at  some 
point  in  the  course  of  the  visual  path  in  the  brain  between  these 
two  places.  The  term  is  not  used  for  cases  in  which  one-half  of 
the  field  is  lost,  owing  to  disease  (detachment  of  the  retina,  etc.) 
within  the  eye  itself. 

In  hemianopsia  the  line  dividing  the  seeing  from  the  blind 
half  of  the  field  passes  vertically  down  the  centre  of  the  latter ; 
or,  it  lies  a  little  to  one  side  of  the  centre  of  the  field,  so  as  to  admit 
of  the  centre  being  included  in  the  seeing  part ;  or — although 
in  other  respects  the  dividing  line  lies  in  the  centre  of  the  field — 
the  fixation  point  is  circumvented  by  it,  so  as  to  leave  that  point 
free,  as  in  Fig.  116  ;  and  this  latter  is  the  most  common  arrange- 
ment.    All  these  varieties  are  termed  complete  hemianopsia. 

Furthermore,  cases  occur  which  are  properly  regarded  as  hemi- 
anopsia, and  yet  in  which  only  the  upper  or  the  lower  half  of  one  side 
of  the  field  is  wanting.     This  is  termed  incomplete  or  partial  hemian- 

360 


OHAP.    XIV.] 


FOCAL    BRAIN   DISEASE. 


361 


opsia.  If  all  three  visual  perceptions  be  lost,  the  hemianopsia 
is  called  absolute  (Fig.  116)  ;  but  if  only  one  (colour)  (Figs.  117  and 
118)  or  two  (colour  and  form)  be  wanting  in  the  defective  part  of 
the  field,  it  is  termed  relative  hemianopsia.  Relative  hemianopsia 
is  the  result  of  a  lesion  of  less  intensity  than  that  which  causes 
absolute' hemianopsia.  The  vast  majority  of  cases  of  hemianopsia 
are  absolute. 

Homonymous  Hemianopsia  is  the  most  frequent  form.  In  it 
the  corresponding  half — the  right  half  or  the  left  half — of  the  field 
of  each  eye  is  wanting,  as  in  Figs.  116  and  118. 

Bi-Temporal   Hemianopsia    is    much   less    common.     Here   the 


Left  Fiela 


Fig.   116. — Case  of  Right  Homonymous  Hemianopsia,  with  word-blind- 
ness.    Line  of  demarcation  passing  round  fixation  point. 


loss  of  vision  exists  in  the  outer  side  of  each  field,  in  consequence  of 
loss  of  function  in  the  mesial  half  of  each  retina. 

Superior  or  Inferior  Hemianopsia,  also  called  Altitudinal  Hemi- 
anopsia, in  which  the  upper  or  lower  half  of  the  field  is  blind,  is  ex- 
ceedingly rare-;  and  it  is  doubtful  whether  Nasal  Hemianopsia  has 
really  been  observed,  although  it  has  been  described.  In  the  latter 
form  the  inner  side  of  the  field  of  one  eye  only  is  lost. 

Cases  of  Double  Hemianopsia  are  those  in  which,  owing  to  a 
cerebral  lesion  on  each  side  of  the  brain,  both  sides  of  each  field 
are  lost.  Usually  in  these  cases  the  functions  of  the  yellow  spot 
are  spared  with  a  corresponding  small  central  field.     Or,  the  whole 


302  DISEASES    OF    THE   EYE.  [chap.   xiv. 


of  one  side  of  each  field,  and  only  half  of  the  other  side  of  each  field 
may  be  lost. 

As  hemianopsia  can  be  caused  by  a  lesion  in  the  optic  com- 
missure, or  in  the  cortical  cerebral  centre  for  vision,  or  by  one  any- 
where in  the  long  visual  path  between  those  two  points,  it  will  be 
convenient  here  to  sketch 

The  Course  of  the  Visual  Path  from  the  Retina  to  the  Visual  Centre 
in  the  Cortex  of  the  Brain. 

Having  passed  along  the  optic  nerve,  the  visual  fibres  coming- 
from  the  mesial  half  of  each  retina,  when  they  reach  the  optic  com- 
missure, cross  to  the  opposite  optic  tract,  while  those  from  the 
temporal  side  of  each  retina  are  continued  in  the  tract  of  the  same 
side.  In  other  words,  the  visual  fibres  from  the  homonymous  half 
of  each  retina — e.g.  from  the  temporal  half  of  the  right  retina,  and 
from  the  mesial  half  of  the  left  retina — pass  wholly  through  the 
corresponding  optic  tract — in  this  case  the  right  tract — on  their  way 
to  the  primary  optic  ganglia.  Therefore  a  lesion,  say,  of  the  right 
tract,  would  cause  loss  of  function  of  the  corresponding  half — the 
right  half — of  each  retina,  and  the  symptom  would  be  blindness 
of  the  opposite  half — the  left  half — of  each  field  of  vision,  termed 
left  homonymous  hemianopsia. 

The  primary  optic  ganglia  are  : — the  external  geniculate  body, 
the  pulvinar  of  the  optic  thalamus,  and  the  anterior  quadrigeminal 
body.  It  is  the  external  geniculate  body  which  receives  the  major 
portion  of  the  fibres  from  the  optic  tract,  and  it  is  the  only  one  of 
the  primary  optic  ganglia,  which  undoubtedly  is  connected  with 
the  act  of  vision,  for  a  lesion  of  it  invariably  gives  rise  to  homony- 
mous hemianopsia.  The  fibres,  which  enter  the  external  geniculate 
body,  end  there  in  fine  branching  terminals  which  are  in  relation 
with  ganglion  cells,  the  axis  cylinders  of  which  form  the  further 
centripetal  path  to  the  cortical  centre  for  vision.  But  the  main 
portion  of  these  axis-cylinders,  or  fibres,  passes  into  the  pulvinar  of 
the  optic  thalamus,  which  also  receives  direct  fibres  from  the  optic 
tract.  Notwithstanding  this  anatomical  fact,  lesions  confined  to 
the  pulvinar  do  not  cause  hemianopsia,  and  hemianopsia  occurring 
with  lesions  of  the  pulvinar  is  due  to  interference  with  the  functions 
of  the  external  geniculate  body,  or  other  portion  of  the  visual  path 
outside  the  pulvinar.  The  anterior  quadrigeminal  body  receives 
a  small  portion  of  the  optic  tract  fibres,  but  these  are  not  visual 


CHAP,  xiv.l  FOCAL    BRAIN   DISEASE.  303 


fibres,  and  lesion  of  this  body  is  never  attended  by  hemianopsia. 
From  the  external  geniculate  body  fibres  pass,  by  way  of  the  retro- 
lenticular  portion  of  the  posterior  limb  of  the  internal  capsule,  to 
the  optic  radiation,  a  large  strand  of  fibres  which  run  in  the  central 
white  matter  of  the  hinder  part  of  the  cerebral  hemisphere,  and 
terminate  in  the  cortex  of  the  occipital  lobe.  Lesions  of  the  optic 
radiation  cause  homonymous  hemianopsia.  Although  fibres  can 
be  anatomically  traced,  passing  from  the  pulvinar  to  the  optic 
radiations  through  the  retro-lenticular  portion  of  the  internal  cap- 
sule, yet  lesions  confined  to  the  latter  place  do  not  cause  hemianopsia, 
and  it  is  evident  that  the  true  visual  fibres  pass  directly  into  the  optic 
radiation. 

The  optic  radiation  sweeps  back  through  the  parietal  lobe,  on 
the  outer  side  of  the  posterior  horn  of  the  lateral  ventricle,  to  reach 
the  mesial  surface  of  the  occipital  lobe,  where  the  cortical  centre 
for  vision  is  situated. 

The  visual  path  thus  is  : — optic  nerve,  optic  commissure,  optic 
tract,  external  geniculate  body,  optic  radiation. 

In  the  path  just  described,  visual  neurons  of  four  different  orders  are 
concerned  :  The  first  neuron  is  represented  by  the  rod  or  cone  with  its 
nucleus  in  the  external  nuclear  layer  of  the  retina,  the  bipolar  cells  of  the 
inner  nuclear  layer  form  the  second  neuron,  and  they  connect  the  first 
with  the  third  neuron,  namely  the  ganglion  cells  of  the  retina  and  their 
axis  cylinders  which  pass  upwards  to  the  primary  optic  or  basal  ganglia, 
and  the  cells  of  the  latter  with  their  axis  cylinders,  which  pass  up  to  the 
visual  centre  in  the  occipital  cortex,  constitute  the  neuron  of  the  fourth 
order.  Lesions  in  the  basal  ganglia  or  anywhere  below,  sooner  or  later 
lead  to  descending  degeneration  and  atrophy  of  the  optic  disc,  whereas 
lesions  of  the  fourth  or  intracerebral  neuron  do  not, 

Henschen,  as  a  result  of  his  clinico-pathological  researches,  would 
confine  the  cortical  centre  for  vision  to  the  middle  part  of  the 
calcarine  fissure — the  upper,  or  cuneic  lip,  representing  the  homo- 
nymous dorsal  retinal  quadrants — while  the  lower  or  lingual  lip 
represents  the  homonymous  ventral  quadrants  of  the  retina  ;  and 
Bolton  and  Brodmann  have  shown  that  the  histological  structure 
of  this  cortical  region  is  highly  specialised.  FJechzig  and  others 
give  a  wider  area  to  the  visual  centre,  which  may  extend  they  say 
to  the  whole  of  the  cuneus,  and  to  the  posterior  part  of  the  lingual 
gyrus. 

Lesions   of   the   cortical   centre   for   vision   cause   homonymous 


364  DISEASES   OF   THE  EYE.  [chap.  xiv. 

hemianopsia.  In  cases  of  hemianopsia  due  to  lesions  of  the  optic 
radiations  or  cortical  centre,  there  is  often  a  peripheral  contrac- 
tion in  the  seeing  side  of  the  field  due  to  diminished  functional 
activity  in  the  opposite  side  of  the  brain  from  that  in  which  the 
disease  is  situated. 

That,  in  hemianopsia,  the  functions  of  the  macula  lutea  are  so 
often  spared  (Fig.  116),  indicates  the  existence  of  some  special  arrange- 
ment of  the  visual  path  and  cortical  centre  for  this  portion  of  the 
retina.  Henschen's  investigations  point  to  tlie  maculo-cortical 
centre  as  being  situated  in  the  anterior  part  of  the  floor  of  the 
calcarine  fissure,  and  to  the  whole  of  each  macula  as  being  repre- 
sented in  each  maculo-cortical  centre,  causing  an  overlapping  of 
nervous  supply  in  those  regions  ;  so  that  in  a  lesion  of  one  cortico- 
macular  centre  the  macular  functions  of  each  eye  would  continue  to 
be  supplied  by  the  cortico-macular  centre  of  the  healthy  side  of  the 
brain.  Occasionally  the  double  innervation  is  not  present,  and  then, 
in  a  cortical  lesion,  the  dividing  line  in  hemianopsia  due  to  a  corti- 
cal lesion  would  pass  through  the  fixation  point.  A  sparing  of  the 
macular  functions  is  also  usual  in  lesions  of  the  most  central  por- 
tions of  the  visual  path.  But  in  lesions  of  the  peripheral  portions 
of  the  optic  radiation,  of  the  primary  optical  centres,  of  the  optic 
tracts,  and  of  the  optic  commissure,  the  dividing  line  almost  in- 
variably passes  through  this  fixation  point.  It  is  therefore  prob- 
able, that  the  point  of  decussation  of  the  maculo-cortical  fibres  lies 
somewhere  in  the  middle  third  of  the  parietal  lobe. 

The  Localisation  of  the  Lesion  in  Cases  of  Hemianopsia  is  a  subject 
of  interest,  and,  in  cases  of  cerebral  surgery,  it  may  be  of  great 
practical  importance. 

Lesions  of  the  centre  of  the  Optic  Commissure,  injuring  the  crossed 
fibres,  produce  as  their  characteristic  symptom  bi-temporal  hemi- 
anopsia, which  may  be  relative  at  first,  beginning,  for  instance,  as  a 
hemiachromatopsia  (Fig.  117),  but  later  on  becoming  absolute.  In 
some  cases  (basal  meningitis,  periostitis,  hyperostosis)  the  diseased 
process  comes  to  a  standstill,  and  the  bi-temporal  hemianopsia 
remains.  But  the  disease  usually  extends  to  the  uncrossed  fibres, 
and  ultimately  causes  complete  blindness.  Optic  atrophy,  often 
commencing  on  the  inner  side  of  the  papilla,  is  nearly  always  present 
at  some  period  of  the  disease.  Other  symptoms  which  may  be 
present  in  lesions  of  the  chiasma  are  anosmia,  paralysis  of  orbital 


CHAP.  XIV.]  FOCAL    BRAIN    DISEASE.  365 

nerves,  and  anaesthesia  of  the  conjunctiva  and  cornea.  The  causes 
are  :  fractures  of  the  body  of  the  sphenoid,  cysts,  tubercle,  tumours, 
•exostoses,  distension  of  the  floor  of  the  third  ventricle  in  cases  of 
internal  hydrocephalus,  and,  most  frequently  of  all,  tumours  of  the 
pituitary  body.  In  the  latter  case  proptosis,  discharge  of  fluid 
from  the  nostril,  and  diabetes  may  be  present.  Syphilitic  gum- 
mata  may  c-ause  transient  recurrent  attacks  of  bi-temporal  hemi- 
anopsia. 

In  Altitudinal  Hemianopsia  the  lesion  must  also,  as  a  rule, 
be  at  the  chiasma,  encroaching  on  it  from  above  or  below.  Sym- 
metrical cortical  lesions  might,  and  optic  neuritis  sometimes  does, 
produce  it. 

In  Nasal  Hemianopsia,  too,  the  lesion  must  be  at  the  chiasma, 
and  must  be  so  situated  in  its  outer  angle  as  to  involve  only  the 
fasciculus  lateralis  or  uncrossed  fibres  of  the  affected  eye.  The 
occurrence  of  binocular  nasal  hemianopsia  is  evidently  almost 
impossible,  implying,  as  it  does,  symmetrical  lesion  of  the  fas- 
ciculus lateralis  of  each  tract.  According  to  Henschen,  a  tumour 
in  the  external  angle  of  the  chiasma  is  apt  to  affect  the  crossed 
fibres  as  well  as  the  uncrossed,  and  to  produce  a  form  of  bilateral 
homonymous  hemianopsia. 

Bi-temporal  hemianopsia  is  a  common  and  early  symptom  in 
enlargement  of  the  pituitary  body  which  may  be  associated  with 
Acromegaly,  or  Gigantism,  or  with  Frohlich's  Syndrome,  namely, 
general  adiposis,  retarded  sexual  development,  etc.  In  some  cases 
headache  and  somnolence  may  be  the  only  noticeable  symptoms, 
while  in  most  acute  cases  ocular  paralysis  may  also  be  present.  In 
most  cases  a  radiograph  will  show  enlargement  or  absorption  of 
the  Sella  turcica.  The  hemianopsia  in  the  earliest  stage  may  exist 
for  colours  only  as  in  one  of  our  cases  (Fig.  117).  In  some 
instances,  during  the  active  stage  of  the  disease,  only  a  bitemporal 
central  scotoma  exists,  and  in  such  cases  the  central  vision  is  sooner 
affected.  Bitemporal  hemianopsia  in  rare  cases  may  be  a  symptom 
of  fracture  of  the  base  of  the  skull.  It  also  may  be  due  to  basal 
syphilis  or  sphenoidal  disease. 

Heteronymous  (nasal  or  bitemporal)  hemianopsia  differs  in  several 
ways  from  homonymous  defects.  In  the  former  the  defects  in  the 
two  eyes  are  often  unsymmetrical,  the  line  of  separation  may  be 
irregular,  there  may  be  contraction  of  the  seeing  halves  of  the 


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CHAP.   XIV.]  FOCAL    BRAIN    DISEASE.  367 

fields,  the   central  vision  is  more  affected,  and  optic  atrophy  or 
even  optic  neuritis  is  much  more  common. 

In  Homonymous  Hemianopsia — which  is  the  commonest  form 
of  the  symptom — localisation  of  the  lesion  is  a  more  difficult  matter 
than  in  any  of  the  other  forms  ;  for  here  the  disease  cannot  be 
situated  at  the  optic  commissure,  but  may  be  in  the  optic  tract, 
or  in  the  visual  centre,  or  anywhere  in  the  lengthened  course  of 
the  visual  path  which  connects  these  two  parts. 

Can  we  distinguish  a  complete  and  absolute  hemianopsia,  due 
to  a  lesion  confined  to  the  cortical  centre  for  vision,  from  a  similar 
defect  in  the  field,  due  to  a  lesion  in  the  optic  radiation,  external 
geniculate  body,  or  optic  tract  ?  We  may  conclude  that  the  hemi- 
anopsia depends  upon  cortical  lesion,  if  it  be  unaccompanied  by 
hemiplegia,  motor  aphasia,  or  paralysis  of  cerebral  nerves,  as  direct 
symptoms  ;  any  or  all  of  these  are  liable  to  accompany  lesions  of 
the  occipital  lobe  as  distant  ^  symptoms.  Pressure  of  a  cerebellar 
tumour  may  interfere  with  the  functions  of  the  healthy  cortical 
centre  for  vision. 

Aphasia,  too,  occasionally  accompanies  right  cortical  hemi- 
anopsia [i.e.  due  to  a  lesion  in  the  left  occipital  lobe),  although  it 
is  not  easy  to  offer  a  satisfactory  explanation  of  the  fact. 

Cortical  hemianopsia  may  be  a  distant  symptom.  Cowers  has 
observed  that,  at  the  onset  of  many  attacks  of  cerebral  haemorrhage, 
hemianopsia  is  present  as  a  distant  symptom  of  a  transitory  char- 
acter— so  transitory,  indeed,  that  it  does  not  complicate  attempts 
at  localisation.  Except  under  this  condition,  distant  hemianopsia 
seems  to  be  rare — a  fact  which  enhances  the  localising  value  of 
the  symptom. 

Cortical  hemianopsia  may  be  incomplete,  the  homonymous 
quadrant  only  of  each  field  being  wanting,  if  the  lesion  be  con- 

^  The  term  '  distant  symptom  '  is  suggested  in  preference  to  those 
in  common  use — namely,  '  indirect  symptom  '  and  '  pressure  symptom.' 
We  cannot  assume  that  these  symptoms  are  less  the  direct  result  of  the 
lesion  than  any  of  the  others  which  are  present ;  and,  in  many  instances 
at  least,  it  is  certain  that  they  cannot  be  due  to  pressiire.  In  short,  we 
do  not  know  what  produces  these  symptoms — they  may  be  caused  by 
inhibition — we  only  know  that  they  are  the  result  of  interference  with 
functions  of  parts  of  the  brain  not  involved  in  the  lesion  ;  and  the  term 
'  distant  symptom  '  conveys  this  idea  sufficiently  well  without  committing 
us  to  any  theory.     The  corresponding  German  term  is  '  Fernwirkung.' 


368 


DISEASES    OF    THE   EYE. 


[chap.    XIV, 


fined  to  the   upper  or   to  the  lower  lips  of   the  calcarine  fissure 
(p.  363). 

In  cortical  lesions  the  hemianopsia  is  usually  absolute.  But  the 
lesion  may  be  such  as  to  destroy  only  the  colour-sense  (Fig.  118), 
without  affecting  the  form-  or  light-sense.  Again,  the  form-sense 
may  be  lost  in  the  half  field  along  with  the  colour-sense,  while  only 
the  light-sense  is  retained.  Furthermore,  cases  of  hemianopsia 
are  on  record  in  which,  in  part  of  the  defect,  both  the  colour-  and 
form-senses  were  absent,  but  the  light-sense  present,  while  in  the 
remainder  of  the  defect  all  three  visual  perceptions  were  lost. 


Lefi  Field 


Fig.  118.— Case  of  Left  Homonymous  H etniachromatopsia  (colour  vision 
only  was  lost  in  the  dotted  portion  of  left  half  of  each  field),  with  absolute 
homonymous  defects  at  A.  Line  of  demarcation  passing  through  fixa- 
tion point.  Associated  with  partial  mind-blindness.  Outer  boundaries 
for  coloiu-s  in  the  right  half  of  each  field  contracted  and  reversed.     Outer 

boundary  for  red  -.-.-.,  for  blue ,  for  green Slight 

apoplectic  attack.     Lesion  almost  certainly  in  cortical  centre. 

It  seems  to  be  now  proved  that  only  a  small  portion  of  the  Optic 
Radiation  can  be  regarded  as  consisting  of  visual  fibres.  A  lesion 
of  the  visual  fibres  of  the  optic  radiation  might  be  distinguished 
from  one  in  the  cortical  centre  by  hallucinations  of  vision  occurring 
in  the  former  and  not  in  the  latter. 

The  symptoms,  in  addition  to  hemianopsia,  due  to  disease  of  the 
External  Geniculate  Body,  which  might  serve  to  distinguish  the  hemi- 
anopsia as  being  caused  by  a  lesion  there,  have  not  as  yet  been 
ascertained,  the  clinical  evidence  being  indefinite.  In  these  cases 
the  dividing  Hue  almost  always  passes  through  the  fixation  point. 


CHAP,  xiv.l  FOCAL    BRAIN    DISEASE.  369 


With  hemianopsia  from  lesions  of  the  Of  tic  Tract,  the  defect 
in  the  fields  may  be  relative  (liemiachromatopsia)  or  incomplete 
(only  homonymous  quadrants  being  lost),  or  complete  and  absolute, 
and  the  dividing  line  almost  always  passes  through  the  fixation 
point.  Lesions  of  the  optic  tract  are,  of  course,  apt  to  implicate 
the  cms  cerebri,  and  in  that  case  hemiplegia  of  the  opposite  side 
of  the  body  would  be  associated  with  the  hemianopsia — e.g.  lesion 
of  the  right  optic  tract  implicating  the  crus  would  be  followed  by 
left  homonymous  hemianopsia  and  left  hemiplegia.  Symptoms  may 
also  be  caused  by  implication  of  cranial  nerves,  especially  of  those 
which  supply  the  orbital  muscles  (chap.  xvi.). 

Atrophy  of  the  optic  nerve,  or  neuritis,  according  to  the  nature 
of  the  lesion,  are  frequently  present. 

A  sign  which  is  sometimes  of  localising  value  in  lesions  of  the 
optic  tract,  is  the  Hemianopic  Pupil  (Wernicke's  pupil-symptom). 
Illumination  of  the  amaurotic  halves  of  the  retinae  produces  a 
more  sluggish  pupil-reaction  than  when  the  light  is  thrown  on  the 
seeing  halves,  because  the  lesion  being  on  the  distal  side  of  the 
corpora  quadrigemina,  the  impulse  cannot  pass  on  to  the  centre  for 
the  third  nerve.  The  difhculty  of  concentrating  light  on  the  blind 
side  of  the  retina,  without  allowing  the  good  side  to  be  exposed 
either  to  diffused  or  to  diascleral  light,  is  great ;  and,  unless  it  be 
obviated,  the  experiment  is  vitiated.  Moreover,  the  experiments 
of  Hess  which  would  show  that  the  pupillo-motor  area  of  the  retina 
is  confined  to  a  region  4  mm.  in  diameter  at  the  centre  of  the  retina, 
and  that  the  pupil-reflex  cannot  be  excited  by  illumination  of  the 
periphery  of  the  retina,  introduces  a  further  difficulty  in  the  obser- 
vation of  this  symptom,  although  it  undoubtedly  can  be  elicited, 
and  we  have  observed  it  extremely  well  marked  in  a  case  of  bi- 
temporal hemianopsia  from  tumour  of  the  pituitary  body. 

The  Diseased  Processes  which  cause  a  Lesion  of  the  Optic  Tract 
are  :  syphilitic  gummata  and  syphilitic  meningitis ;  new  growths, 
including  tubercle ;  while  softening  and  haemorrhage  are  rare. 
Tumours  of  the  optic  thalamus,  lenticular  nucleus,  or  temporo- 
sphenoidal  lobe  may  also  injure  the  tract  by  extension  or  pressure. 

In  hemianopsia  the  Prognosis  for  recovery  of  vision  in  the 
defective  halves  of  the  fields  depends,  of  course,  upon  the  nature 
of  the  lesion.  But  recovery  is  rare,  especially  in  the  most  common 
class  of  cases — those,  namely,  which  are  due  to  cerebral  apoplexy. 

u 


370  DISEASES   OF   THE   EYE.  [chap.  xiv. 

In  Right  Homonymous  Hemianopsia,  wherever  the  position  of  the 
lesion  may  be,  a  greater  difficulty  in  reading  is  experienced  than  in  left 
hemianopsia.  This  is  due  to  the  fact  that  we  read  from  left  to  right  ; 
and  that,  owing  to  the  defect  being  on  the  right  side,  the  word  immediately 
following  that  at  which  the  patient  is  looking  cannot  be  seen  at  the  same 
moment.  A  lesser  difficulty  in  reading  occurs  in  cases  of  left  homonymous 
hemianopsia — namely,  when  the  commencement  of  the  line  following 
that  which  is  being  read  has  to  be  picked  up. 

Word-Blindness  is  the  term  given  to  an  inability  to  understand  written 
or  printed  characters,  although  they  and  other  small  objects  can  be  dis- 
tinctly seen.  Other  visual  objects  are  named  with  ease  (no  visual  aphasia). 
The  patient  can  express  his  ideas  in  writing,  or  write  from  dictation, 
yet  cannot  understand  what  he  has  just  written,  nor  can  he  copy  written 
or  printed  words.  He  understands  the  meaning  of  spoken  words,  and 
the  use  of  all  objects  around  him  (no  mind-blindness).  He  can  generally 
recognise  individual  letters  with  some  difficulty.  This  is  '  pure  word- 
blindness,'  or  '  sub-cortical  alexia.'  When  combined  with  inability  to 
write  spontaneously  or  from  dictation,  it  is  known  as  '  cortical  alexia.' 
The  condition  has  been  occasionally  complicated  with  right  homonymous 
hemianopsia  (Fig.  116).  In  those  cases  where  an  autopsy  was  obtained 
the  lesion  was  found  in  the  left  occipital  lobe.  Word-blindness  with 
agraphia  or  cortical  alexia  is  due,  according  to  Dejerine  and  AVernicke,  to 
a  lesion  in  the  ce  itre  for  visual  memory  for  words,  which,  in  right-handed 
people,  is  the  left  angular  gyrus  and  inferior  parietal  lobule. 

Congenital  Word-Blindness  is  probably  not  a  rare  condition,  although 
liable  to  be  overlooked.  It  is  shown  to  be  present  when  it  is  found  ex- 
ceedingly difficult,  or,  in  severe  cases,  impossible,  to  teach  a  child  with 
healthy  eyes,  normal  acuity  of  vision,  and  good  general  intelligence  to 
read,  sometimes  even  common  words  of  one  syllable,  although  he  can  learn 
to  recognise  them  if  permitted  to  spell  them  aloud.  The  defect  is  probably 
due  to  imperfect  development  of  the  cortical  centre  for  the  visual  memory 
for  words  in  the  left  cerebral  hemisphere,  while  the  centre  for  the  auditory 
memory  of  words  is  unimpaired.  As  a  rule,  except  in  the  severest  cases, 
numerals  and  music  can  be  read.  Hemianopsia  is  never  associated  with 
this  state.  The  condition  sometimes  runs  in  families.  When  the  word- 
blindness  is  not  very  marked,  and  when  it  is  recognised  in  childhood,  a 
great  deal  can  be  done  by  careful,  long-continued,  and  individual  tuition 
to  effect  a  cure.  These  children  should  not  be  sent  to  school.  Cures 
are  probably  brought  about  by  stimulation  of  the  defective  word-memory 
centre,  or  by  development  of  the  corresponding  centre  in  the  opposite 
side  of  the  brain. 

Visual  Aphasia  consists  in  inability  to  name  objects  seen,  the  use  of 
which  is  kno-s^m.  The  objects  can  be  named,  if  the  patient  be  allowed 
to  feel  them  even  with  his  eyes  closed.  A  few  cases  of  this  affection  have 
been  recorded,  and  in  all  there  was  right  homonymous  hemianopsia. 
Alexia  and  agraphia  sometimes  coexisted. 

Dyslexia. — This  symptom  was  first  described  by  Berlin.  In  a  wide  sense 
it  belongs  to  the  aphasic  group,  and  is  in  fact  a  limited  form  of  visual 
aphasia.     It  consists  in  want  of  power  on  the  patient's  part  to  read  more 


CHAP.   XIV.]  FOCAL    BRAIN   DISEASE.  371 


than  a  very  few — four  or  five — words  consecutively,  either  aloud  or  to 
himself.  The  difficulty  is  not  caused  by  dimness  of  sight,  nor  by  pain  in 
the  eye  or  head,  but  simply  by  an  unconquerable  feeling  of  dislike  or 
disgust,  due  to  the  mental  effort.  After  a  few  words  which  can  be  well 
understood  have  been  read,  the  book  is  pushed  away,  and  the  head  drawn 
backwards  and  tm-ned  aside  ;  and  then  in  a  moment  or  two  the  patient 
may  be  tempted  to  repeat  the  effort,  but  with  the  same  result  after  a 
very  few  words  have  been  read.  The  symptom  comes  on  suddenly,  and 
has  been  usually  the  first  sign  of  the  presence  of  cerebral  disease.  Although 
in  most  of  the  cases  the  dyslexia  disappeared  in  the  course  of  a  few  weeks, 
either  permanently  or  to  recur  later  on,  yet  other  symptoms  soon  followed 
its  first  onset,  such  as  headache,  giddiness,  aphasia,  hemianopsia,  paralysis 
of  the  tongue,  hemiansesthesia,  hemiplegia,  twitching  of  the  facial  muscles, 
etc.  All  the  recorded  cases  had  a  fatal  termination.  The  lesion  was 
situated,  in  all  but  one  of  those  cases  where  an  autopsy  was  obtained,  in 
the  neighbourhood  of  Broca's  lobe.  In  one  case  the  left  hemisphere  was 
normal,  while  the  right  hemisphere  was  extensively  diseased. 

Amnesic  Colour-Blindness  is  a  symptom  which  is  most  probably  due 
to  a  lesion  in  the  occipital  lobe,  interrupting  the  paths  between  the  centre 
for  vision  and  the  speech  centre.  It  has  always  been  accompanied 
by  right  homonymous  hemianopsia.  In  this  condition  the  patient  sees 
colours  and  can  recognise  them,  and  he  can  perform  the  colour  tests,  but 
he  is  unable  to  name  each  colour. 

Visual  Hallucinations  may  occur  in  cases  of  homonymous  hemianopsia 
in  the  blind  side  of  the  field  only,  and  are  due  to  irritation  of  the  visual- 
memory  centre.  Homonymous  hemianopic  hallucinations,  persisting  for 
years  without  hemianopsia,  have  also  been  observed.  Visual  hallucina- 
tions also  occur  very  occasionally  in  connection  with  glaucoma. 

Mind-Blindness,  also  called  Optic  Amnesia,  is  a  symptom  fu^st  observed 
by  Munk  in  his  experiments  upon  dogs.  It  consists  in  the  loss  of  power 
of  recognising  objects,  while  the  power  of  seeing  them  remains.  A  whip 
is  seen  by  the  animal,  but  inspires  no  terror  ;  a  tempting  morsel  is  seen, 
but  excites  no  desire.  The  symptom  was  caused  by  destruction  of  a  region 
situated  chiefly  in  the  posterior  division  of  the  second  external  convolution 
of  the  dog's  brain. 

It  has  also  been  observed  in  man.  The  patient  fails  to  recognise  the 
most  familiar  objects  by  sight.  In  one  case  the  patient  could  not  recognise 
his  wife  until  he  heard  her  voice.  There  are  two  forms  of  mind-blindness 
— the  cortical  and  the  transcortical.  In  the  former,  the  lesion  is  in  the 
centre  for  memory  ;  and  the  patient  has  lost  the  power  of  visual  imagina- 
tion, and  cannot  describe  visual  objects  from  memory.  In  the  latter,  the 
connecting  path  between  the  centre  for  vision  and  the  visual  memory  centre 
is  interrupted,  and  the  patient,  though  he  can  describe  an  object  from 
memory,  is  unable  to  recognise  it  when  looking  at  it.  Loss  of  the  faculty 
of  orientation  is  a  form  of  mind-blindness.  Hemianopsia  is  present  in 
the  majority  of  cases  of  mind-bliadness  ;  and  colour-blindness,  complete 
or  hemianopic,  is  not  unusual.  The  lesion  has  been  found  in  the  occipital 
lobe,  usually  on  the  left  side,  involving  sometimes  the  parietal  convolu- 
tions.    It  usually  consists  in  haemorrhage  or  softening,  and  the  symptom 


372  DISEASES   OF   THE   EYE.  [chap.  xiv. 


is  consequently  s\idden  in  its  onset ;  but  it  also  occurs  from  tumours. 
Exhausting  illnesses,  by  reducing  the  mental  energy,  may  produce  a  con- 
dition of  mind-blindness. 

Some  authors  localise  the  centre  for  visual  memory  in  the  angular 
gyrus,  whilst  others  take  for  it  the  whole  of  the  occipital  lobe,  except 
the  cuneus  and  its  neighbourhood. 


Part  II. 

OCULAR  DISEASES  AND  SYMPTOMS  LIABLE  TO  ACCOMPANY 
CERTAIN   DIFFUSE   ORGANIC   DISEASES   OF   THE   BRAIN. 

There  are  organic  diseases  of  the  brain  which  are  not  focal,  and 
which,  as  they  attack  extensive  regions  of  the  brain  substance,  may 
be  called  diffuse.  Under  the  same  heading  may  be  placed  some 
diseased  cerebral  states  which  we  cannot  doubt  are  organic,  although 
their  pathology  is  as  yet  unascertained.  It  is  proposed  here  to 
describe  the  points  of  ophthalmological  interest  which  belong  to 
some  of  these  diffuse  brain  diseases. 

Disseminated  Sclerosis  of  the  Brain  and  Spinal  Cord.— Central 
Colour  Scotoma  is  the  most  usual  defect  of  sight  in  this  disease  (Fig. 
119),  and  in  a  few  cases  absolute  central  scotoma  is  present.  It 
is  due  to  retro-bulbar  neuritis  (p.  347),  which  is  now  recognised 
to  occur  most  commonly  as  a  symptom  of  disseminated  sclerosis. 
Irregular  defects  in  the  periphery  of  the  fields — sometimes  only  for 
colour — or  regular  concentric  contraction  may  be  found.  These 
defects  may  be  in  one  or  in  both  eyes  ;  they  most  commonly  come 
on  very  rapidly,  and  they  often  get  better,  or  may,  after  a  time, 
get  quite  well.  Even  complete  blindness,  lasting  as  long  as  several 
months,  occasionally  occurs ;  but  permanent  complete  blindness 
is  rare.  The  opthalmoscopic  appearances  do  not  always  coincide 
with  the  state  of  the  vision  ;  for  with  marked  defect  of  sight  the 
fundus  oculi  may  be  normal,  or  the  vision  may  be  normal,  while 
the  optic  papilla  looks  diseased,  or  both  sight  and  ophthalmoscopic 
appearances  may  be  abnormal.  The  most  common  opthalmoscopic 
change  is  a  not  very  intense  atrophic  appearance  of  the  whole  surface 
of  the  papilla,  or  its  temporal  third  alone  may  be  affected  in  this 
way.  But  in  these  latter  cases,  where  the  temporal  third  alone 
shows  atrophy,  a  central  scotoma  is  not  necessarily  present,  nor 
9,re  the  papillo-macular  fasciculi  in  the  nerve  diseased.     In  a  very 


CflAP.    XIV.  i 


DIFFUSE   BRAIN   DISEASE. 


3?S 


few  cases  optic  neuritis  becomes  apparent  at  the  papilla.  The 
ophthalmoscopic  changes  may  be  present  in  both  eyes  or  in  only 
one.  Uhthoff  has  shown  by  pathological  investigations  that,  in 
disseminated  sclerosis,  disease  can  exist  in  the  trunk  of  the  optic 
nerve,  without  any  abnormal  ophthalmoscopic  appearances,  or  defect 
of  sight.  Sometimes  defects  of  vision  and  ophthalmoscopic  changes 
precede  all  other  symptoms  by  long  periods,  or  they  appear  in  the 
very  early  stages  of  the  disease  ;  but  more  commonly  they  do  not 
come  on  until  other  symptoms  have  been  present  for  some  time. 
In  all  cases  of  retro-bulbar  neuritis  exaggerated  tendon  reflexes  and 


Lex't  field 


Right  Field 


Fig.  119. — Case  of  Disseminated  Sclerosis.  In  right  field  a  very  small 
central  scotoma  for  pale  green,  and  relative  for  white.  A  mist  before  the 
R.E.  for  fourteen  days,  otherwise  strong  and  healthy.  Fundus  normal. 
V  =  6/18.  Exaggerated  knee-reflex.  No  nystagmus,  nor  nystagmic 
twi tellings.  A  week  later  nystagmic  twitchings  in  extreme  lateral  posi- 
tions.    L.E,  healthy. 

other  well-known  signs  of  disseminated  sclerosis  should  be  looked 
for.  At  the  commencement  of  the  attack  of  defective  vision,  the 
patient  complains  of  some  pain  on  movement  of  the  eyeball,  and 
gentle  pressure  backwards  of  the  globe  causes  pain  in  the  back  of 
the  orbit. 

Nystagmus,  isolated  and  often  fleeting  paralyses  of  orbital 
muscles,  especially  of  the  sixth  nerves,  and  nuclear  paralysis,  are  de- 
rangements of  the  oculo-motor  apparatus,  which  are  liable  to  be 
present  in  disseminated  sclerosis.  Marked  exterior  ophthalmoplegia 
is  rare ;  but  the  paralyses  of  nuclear  origin  of  which  there  can  be  no 


374  DISEASES   OF   THE   EYE.  [chap.  xiv. 

doubt,  are  loss  of  conjugate  motion  to  one  or  other  side,  and  defective 
power  of  convergence.  Nystagmus  is  present  in  about  50  per  cent. 
of  the  cases,  and  is  either  of  the  ordinary  kind  or  consists  merely 
in  nystagmic  twitchings,  more  particularly  at  the  extreme  lateral 
position  of  the  eyeballs.  Very  slight  twitchings  in  these  extreme 
positions  are  of  no  import,  as  they  occur  even  in  the  healthy  state. 
As  true  nystagmus  is  an  uncommon  symptom  in  other  diseases  of 
the  general  nervous  system,  it  is  of  considerable  value  in  the  diag- 
nosis. Nystagmic  twitchings,  while  they  do  occur  in  other  general 
nervous  diseases,  are  more  common  in  disseminated  sclerosis  than 
in  any  other  of  these  diseases.     Miosis  may  be  present. 

Disseminated  sclerosis  in  its  early  stages  is  apt  to  be  mistaken 
for  hysteria,  owing  to  the  presence  of  such  symptoms  as  transitory 
loss  of  power  in  limbs,  aphonia,  convulsive  seizures,  hysterical 
manner,  and  so  on,  and  here  the  eye-symptoms  may  come  to  our 
aid.  In  hysteria  the  ophthalmoscopic  appearances  are  normal ;  the 
fields  of  vision,  if  deranged,  are  contracted,  central  scotoma  being 
rare,  and  when  the  fields  are  contracted  the  colour  boundaries  often 
do  not  recede  in  their  regular  order — the  field  for  red,  for  example, 
may  be  wider  than  that  for  the  other  colours.  In  hysteria,  again, 
it  may  be  found  impossible  to  examine  the  colour  fields  at  all,  all 
colours  being  named  dark  or  black  ;  and  finally  oculo-motor  dis- 
turbances rarely  occur. 

Diffuse  Sclerosis  of  the  Brain. — In.  some  rare  cases  of  this  disease, 
headache,  \omiting,  and  double  optic  neuritis  may  lead  to  the  diagnosis 
of  cerebral  tumour,  an  error  in  diagnosis  which,  with  our  present  know- 
ledge, it  is  impossible  to  avoid,  unless  there  be  also  focal  symptoms  that 
would  point  with  certainty  to  a  tumour.  The  mistake  will  not  often 
occur,  as  diffuse  sclerosis  of  the  brain  is  exceedingly  rare. 

General  Paralysis  of  the  Insane. — Derangements  of  the  intrinsic 
muscles  of  the  eyeball,  orbital  paralyses,  atrophy  of  the  optic  disc, 
and  mind-blindness  are  the  eye-symptoms  which  may  be  found  in 
this  disease. 

The  Pupil,  etc. — The  pupils  are  usually  contracted  in  the  early 
stages,  and  dilated  at  later  periods.  An  early  symptom  is  slight 
inequality  in  the  pupils  (Anisocoria),  with  somewhat  sluggish  reaction 
of  the  wider  one,  and,  also  at  an  early  period,  there  is  apt  to  be  loss 
of  the  pupil-reflex  to  sensory  stimuli.  Later  on  the  larger  pupil 
does  not  react  to  light  at  all,  while  its  fellow  does  so  normally,  and 


CHAP.  XIV.]  DIFFUSE   BRAIN   DISEASE.  375 


sight  is  good.  Sometimes  the  inequality  of  the  pupils  varies,  so 
that  the  pupil  which  was  at  first  the  larger,  now  becomes  the  smaller 
one.  The  so-called  paradoxical  pupil-symptom  is  an  early  augury 
of  coming  paralysis,  and  consists  in  this,  that  when  a  strong  beam  of 
light  is  thrown  into  the  eye  with  the  focal  illumination,  the  pupil 
at  first  contracts  fairly  well,  then  dilates  slightly,  contracts  again, 
and  after  a  few  such  oscillations  finally  dilates  widely,  although  the 
strong  light  still  shines  into  the  eye.  The  Argyll  Eobertson  pupil 
is  only  found  in  some  cases,  and  then  usually  in  the  late  stages,  but 
it  does  occasionally  present  itself  in  the  initial  stages.  Sometimes 
the  pupil  is  irregular  in  shape. 

Paralyses  of  Orbital  Muscles. — These  are  of  rarer  occurrence  than 
paralysis  of  the  pupil ;  but  the  third  and  sixth  nerves  are  occasionally 
paralysed  even  in  the  early  stages,  and  in  these  stages,  too,  ptosis 
and  transient  nystagmus  and  twitchings  of  the  eyelids  may  be 
seen. 

Oftic  Atrophy. — This  is  found  in  8  to  10  per  cent,  of  the  cases  of 
general  paralysis,  and  is  then  seen  for  the  most  part  in  the  late  stages. 
But  it  has  sometimes  come  on  in  a  very  early  period,  and  has  even 
preceded  every  other  symptom  by  several  years.  It  generally  ends 
in  blindness.  Occasionally  slight  hyperaemia  of  the  disc  or  optic 
neuritis  is  seen.  Atrophy  of  the  optic  nerve  and  orbital  paralyses 
are  more  often  seen  when  tabetic  symptoms  are  present. 

Mind-blindness  occurs  in  cases  of  general  paralysis,  usually  in 
the  advanced  stages. 

Amaurotic  Family  Idiocy. — This  disease  occurs  in  children  during 
the  first  year  of  life,  and  most,  if  not  all,  of  the  cases  recorded  occurred  in 
Jewish  families.  Family  predisposition  is  strongly  marked,  as  many 
as  five  children  in  a  family  of  seven  having  been  attacked.  The  causes 
which  have  been  assigned  are  neurotic  taint,  blood  relationship  between 
the  parents,  and  traumatism  of  the  mother  during  pregnancy.  Syphilis 
does  not  seem  to  play  any  part  in  the  etiology. 

The  children  are  born  sound  and  healthy,  and  continue  to  be  so  for 
some  months.  They  then  cease  to  develop  mentally,  and  idiocy  is  gradu- 
ally established.  At  the  same  time  paresis  or  paralysis,  either  flaccid  or 
spastic,  of  the  greater  part  of  the  body  appears,  while  the  reflexes  may  be 
deficient  or  increased.  Hyperacusis  is  often  present.  A  chief  and  very 
early  symptom  of  the  disease  is  loss  of  sight,  ending  in  absolute  blindness, 
with  certain  characteristic  ophthalmoscopic  appearances,  and  nystagmus 
and  strabismus  are  sometimes  present.  A  slowly  increasing  marasmus 
leads  to  a  fatal  termination  before  the  end  of  the  second  year,  as  a  rule. 
Waren  Tay  first  observed  the  peculiar  ophthalmoscopic  appearances,  and 


376  DISEASES   OF   THE  EYE.  [chap.  xiv. 

Sachs  described  the  clinical  history,  general  symptoms,  and  morbid  changes 
in  the  brain. 

The  ophthalmoscopic  appearances  are  as  follows : — There  is  at  first 
no  change  in  the  optic  discs.  At  the  macula  lutea  in  each  eye  there  is  a 
large  white  spot,  rather  diffuse,  with  softened  edges,  and  about  twice  the 
size  of  the  optic  papilla.  In  its  centre  there  is  a  brownish-red,  fairly 
circular  spot,  which  contrasts  strongly  with  the  white  around  it.  This 
central  spot,  as  Tay  says,  has  not  the  appearance  of  a  hsemorrhage,  nor  of 
pigment,  but  suggests  a  gap  in  the  white  patch  through  which  the  healthy 
structures  are  seen.  In  short,  the  appearance  reminds  one  of  that  seen  in 
cases  of  embolism  of  the  central  artery  of  the  retina  (p.  325  and  Plate  VII. 
Fig.  1).  At  a  later  period,  with  complete  amaurosis,  atrophy  of  the  optic 
nerve  is  found. 

In  the  brain  the  pathological  changes  consist  in  degeneration  of  the 
pyramidal  cells  of  the  cerebral  cortex.  In  the  pons  and  medulla  oblongata, 
degeneration  of  the  pyramidal  fibres  and  of  the  fillet  has  been  found  ;  and 
in  the  spinal  cord,  degeneration  of  both  the  crossed  and  direct  pyramidal 
tracts  has  been  seen  and  also  disease  of  the  ganglion  cells  of  the  retina 
similar  to  that  in  the  cerebral  cortex.  The  normal  absence  of  the  ganglion 
cell  layer  at  the  macula  lutea,  and  the  fact  that  it  is  thickest  just 
around  the  latter,  go  far  to  explain  the  ophthalmoscopic  appearances. 

Maculo-Cerebral  Degeneration  (Familial). — In  this  disease,  as  in  that 
just  described,  disease  of  the  macula,  which  affects  several  members  of  a 
family,  is  usually  associated  with  defective  intelligence,  but  it  differs  from 
the  former  in  as  much  as  it  begins  at  a  later  age  and  is  not  confined  to 
Jews.  When  about  six  or  eight  years  of  age,  two  or  more  of  the  children 
are  noticed  to  have  defective  sight  and  weakening  of  the  intellect.  As 
the  disease  progresses  they  become  imbecile  but  not  completely  blind. 

The  ophthalmoscope  shows  pallor  of  the  optic  discs  with  narrow  vessels 
and  a  peculiar  affection  of  the  retina  at  the  macula  lutea.  The  macular 
changes  consist  of  dirty,  yellowish-grey  spots  and  fine  granular  pigmenta- 
tion, or  sometimes  there  is  a  dark  reddish  pigmented  patch  ;  minute  whitish 
dots  may  also  be  scattered  over  a  larger  area. 

The  defect  in  the  vision  reveals  itself  as  a  central  scotoma,  at  first 
relative  and  then  absolute,  with  a  normal  peripheral  field. 

In  cases  which  begin  later,  about  twelve  years  of  age,  the  intellect  is 
not  affected  as  a  rule.  The  cause  and  the  pathology  of  the  disease  are 
unknown.     Consanguinity  in  the  parents  was  noted  in  many  instances. 

Meningitis. — Inflammation  of  the  cerebral  meninges,  of  whatever 
form,  and  whether  at  the  base  or  on  the  convexity  of  the  brain, 
is  liable  to  be  accompanied  by  optic  neuritis.  In  the  early  stages 
irritative  lesions  may  cause  spasmodic  miosis,  and  conjugate  devia- 
tions of  the  head  and  eyes,  also  of  spasmodic  nature.  Later  on 
ocular  paralyses,  pain,  or  ansesthesia  of  regions  supplied  by  the  fifth 
nerve,  and  defects  in  the  fields  of  vision  from  pressure  on  the  optic 
tracts  or  commissure,  may  be  found. 


CiiAi>.  XIV.]  DIFFUSE   BkAIN   DISEASE.  37? 

Acute  Tubercular  Meningitis. — In  a  large  percentage  of  tlie  cases 
of  this  form  of  meningitis  miliary  tubercles  in  the  chorioid  are 
present,  if  carefully  looked  for,  and  here  the  electric  ophthalmoscope 
is  very  useful  (p.  220).  Optic  neuritis  is  more  common  than  in  any 
other  form  of  meningitis,  as  are  also  orbital  paralyses,  in  consequence 
of  the  tendency  of  this  form  to  attack  the  base  of  the  brain.  The 
paralyses  are  often  transitory  and  variable. 

Cerebrospinal  Meningitis. — Eye-symptoms  are  often  present 
both  in  the  epidemic  and  sporadic  forms  of  this  disease.  Swelling 
of  the  eyelids,  conjunctivitis,  and  photophobia  are  frequent,  even 
in  the  early  stages.  The  pupils  may  be  unequal,  contracted,  or 
dilated.  There  may  be  ulceration  of  the  cornea,  parenchymatous 
keratitis,  or  deep  purulent  infiltrations.  Eetinitis  and  plastic  irido- 
chorioiditis,  followed  by  retinal  detachment,  may  be  found,  or  there 
may  be  purulent  irido-chorioiditis,  with  purulent  infiltration  of  the 
vitreous  humour,  going  on  to  panophthalmitis.  If  the  fundus  can  be 
examined,  optic  neuritis  or  neuro-retinitis  will  often  be  seen,  or  throm- 
bosis of  the  central  vein,  with  retinal  haemorrhages.  Each  epidemic 
of  cerebro-spinal  meningitis  is  apt  to  be  associated  with  some  one  of 
these  conditions  as  its  special  type  of  eye-affection.  The  eye-affections 
in  cerebro-spinal  meningitis  then  are  very  grave  ;  but  some  of  the 
cases  of  irido-chorioiditis  do  recover,  with  retention  of  good  sight. 

Traumatic  Meningitis. — Falls  and  blows  on  the  head  which  do 
not  fracture  the  skull  are  held  by  many  to  be  capable  of  causing 
meningitis,  and  occasionally,  che  inflammatory  process,  reaching 
the  optic  nerve,  creeps  down  it  to  the  optic  papilla,  where  it  may  be 
diagnosed  with  the  ophthalmoscope. 

Hydrocephalus. — Well-marked  papillitis,  or  neuritic  atrophy,  is 
sometimes  found  in  congenital  hydrocephalus,  or  in  the  hydro- 
cephalus which  makes  its  appearance  in  infancy  or  childhood  ;  and 
it  would  probably  be  more  common,  but  for  the  compensation  for 
the  increased  intra-cranial  pressure,  which  distension  of  the  sutures 
and  fontarelles  must  provide.  In  the  acquired  hydrocephalus  of 
later  life,  optic  neuritis  passing  over  to  optic  atrophy  is  the  rule  ; 
and  such  cases  may  closely  simulate  an  intra-cranial  tumour  in  all 
their  other  symptoms  as  w^ell.  Bi-temporal  hemianopsia  is  apt  to 
be  present,  owing  to  pressure  on  the  optic  commissure  by  the  dis- 
tended floor  of  the  third  ventricle.  Vision  has  been  restored  by  a 
palliative  decompression  operation. 


378  DISEASES   OF   THE   EYE.  [chap.  xiv. 

Infantile  Paralysis. — Hemianopsia  has  been  noted  in  a  very 
few  cases  of  this  affection  ;  and  papilKtis,  with  some  orbital  paralysis, 
has  also  been  seen,  but  usually  there  are  no  eye-symptoms. 

Paralysis  Agitans. — In  some  cases  a  fine  vibratory  tremor  may 
be  noticed  along  the  margin  of  the  upper  lid,  especially  when  the 
eyes  are  closed,  and  the  lids  will  be  found  to  be  unusually  rigid  on 
an  attempt  being  made  at  passive  opening  of  them.  The  slowness 
of  muscular  action  in  other  parts  does  not  affect  the  motions  of  the 
eyeballs.  If  a  patient  be  called  on  to  look  in  any  direction,  the 
eyes  are  instantly  turned,  while  the  head  slowly  follows  them. 

Epilepsy. — A  visual  aura  is  more  common  than  any  other  special 
sense  aura  in  idiopathic  epilepsy.  It  may  take  the  form  of  sub- 
jective sensations  of  lights,  colour,  flames,  megalopsia  or  micropsia, 
etc.  ;  or  visual  hallucinations  may  occur  ;  or  there  may  be  simple 
homonymous  hemianopsia.  Where  epilepsy  is  due  to  organic  brain 
disease,  a  visual  aura,  occurring  ahvays  in  homonymous  sides  of  the 
fields,  is  important,  as  indicating  the  occipital  lobe  as  the  region  of 
the  brain  in  which  the  discharge  originates.  At  the  onset  of  an 
epileptic  fit,  there  is  often  conjugate  lateral  deviation  of  the  eyes 
to  the  opposite  side  of  the  body  from  that  on  which  the  convulsions 
commence,  with  rotation  of  the  head  in  the  same  direction,  while 
subsequently  the  eyes  may  suddenly  be  turned  in  the  opposite  direc- 
tion. The  condition  of  the  pupils  varies,  often  even  in  one  and  the 
same  fit.  At  the  onset  they  are  usually  normal  or  contracted ; 
but  during  the  tonic  spasm  they  become  dilated,  and  remain  so 
until  consciousness  returns.  The  pupillary  light-reflex  is  lost — a 
point  of  importance  in  the  diagnosis  of  a  true  epileptic  fit  from  an 
hysterical  attack,  in  which  latter  it  is  retained.  After  a  fit,  rapid 
changes  in  the  size  of  the  pupil  may  sometimes  be  seen,  and  these 
are  valuable  as  evidence  of  the  fit  having  been  a  genuine  one.  The 
ophthalmoscopic  appearances  during  a  fit  vary  in  different  cases. 
In  some  they  are  normal,  in  others  there  is  marked  pallor  of  the  disc 
and  contraction  of  the  blood-vessels,  and,  again,  in  others  the  papilla 
is  hypercemic  and  the  retinal  veins  enlarged.  Optic  neuritis  and 
optic  atrophy  do  not  belong  to  epilepsy  ;  and  if  found  they  can 
be  regarded  only  "as  complications.  Between  attacks  the  fundus 
may  be  normal ;  but  it  is  not  unusual  to  find  a  high  degree  of 
hypersemia  of  the  retina  and  papilla,  which  may  continue  for  some 
days  or  hours,  or  may  even  become  chronic.     The  fields  of  vision 


CHAP.  XIV.]  DIFFUSE   BRAIN   DISEASE.  379 

after  a  fit,  and  sometimes  as  a  permanent  state,  are  concentrically 
contracted  ;  or  there  may  be  colour-blindness,  and  the  central 
acuteness  of  vision  may  be  reduced.  The  state  of  the  fields  is  a 
valuable  aid  in  the  detection  of  simulation.  Transitory  amblyopia 
(migraine,  scotoma,  etc.)  is  more  frequent  in  connection  with  epilepsy 
than  under  any  other  condition.  It  may  precede  the  true  attack 
by  years,  or  it  may  occur  with,  or  for  an  hour  or  so  before,  the  fits, 
or  it  may  be  substituted  for  them.  Inasmuch  as  this  transitory 
amblyopia  is  often  attended  by  disturbances  in  speech,  or  in  the 
intelligence,  or  by  passing  paralysis,  and  as  both  eyes  are  usually 
attacked  by  it,  frequently  in  the  form  of  homonymous  hemianopsia, 
it  is  obvious  that  its  cause  resides  in  the  visual  cortex.  Occasionally 
the  blindness  is  monocular,  and  must  then  be  referred  to  disturbance 
in  the  circulation  of  the  retina  or  optic  nerve.  Given  a  predisposition 
to  epilepsy,  irregularities  in  refraction  may  at  times  prove  the  ex- 
citing cause  of  an  attack ;  and  if  correcting  glasses  be  worn  by  these 
patients  at  a  sufficiently  early  period,  the  fits  may  cease,  or  at  least 
become  less  severe  in  a  certain  proportion  of  the  cases.  Further 
investigations  on  this  subject  are  required,  especially  as  concerns 
the  permanence  of  cures. 

Chorea. — It  is  probable,  that  in  some  cases,  at  least,  of  this 
affection,  cerebral  embolism  may  be  taken  as  the  cause.  Several 
instances  of  embolism  of  retinal  vessels  have  been  seen  in  immediate 
connection  w4th  the  onset  of  chorea. 

In  chorea  the  eyes  participate  in  the  irregular  jerky  motions, 
and  the  spasm  may  be  so  unequal  in  the  two  eyes  as  to  cause  brief 
diplopia  ;  although,  not  being  constant,  it  is  little  heeded  by  the 
patients,  and  is  rarely  mentioned  by  them. 


Part  III. 

OCULAR  DISEASES  AND  SYMPTOMS  LIABLE  TO  ACCOMPANY 
CERTAIN  DISEASES  AND  INJURIES  OF  THE  SPINAL 
CORD. 

Tabes  Dorsalis. — Amongst  the  ocular  complications  to  be  found 
in  this  disease,  Atrophy  of  the  Optic  Nerve  (p.  354)  is  the  most  serious. 
It  occurs  in  about  20  per  cent,  of  the  cases,  and  commences  more 
frequently  in  the  pre-ataxic  period  than  subsequently.     Rarely  it  is 


380  DIjSEAJ^ES   of   the  eye,  [cHAi>.  xiV. 

the  first  symptom,  preceding  all  spinal  symptoms  by  from  two 
to  twenty  years,  but  it  sometimes  commences  in  the  later  stages 
of  locomotor  ataxy.  Coming  on  in  the  pre-ataxic  stage,  optic 
atrophy  seems  very  often  to  have,  as  it  were,  a  favourable  influence 
on  the  spinal  disease,  the  spinal  symptoms  already  existing  becoming 
ameliorated  or  disappearing,  while  the  further  progress  of  the  disease 
is  retarded  or  averted.  It  is  indeed  rare  for  tabetic  patients  who 
go  blind  at  an  early  stage  of  the  disease  to  become  ataxic  later ; 
but  if  the  ataxy  be  once  well  marked,  it  does  not  improve  with  a 
subsequent  development  of  optic  atrophy.  It  sometimes  occurs 
that  the  onset  of  optic  atrophy  in  one  eye  precedes  that  in  the  other 
by  a  long  interval,  even  by  many  years  ;  but  usually  the  eyes  are 
affected  simultaneously,  or  at  a  short  interval.  The  relation  be- 
tween the  optic  atrophy  and  the  spinal  disease  is  not  as  yet  well 
understood.  The  atrophy  is  probably  merely  a  manifestation  of 
a  diseased  process  in  the  optic  nerve,  similar  to  that  which  attacks 
the  posterior  columns  of  the  cord.  The  fields  of  vision  are  usually 
concentrically  contracted  (see  also  p.  22). 

Paralysis  and  Ataxy  of  the  Orbital  Muscles. — Paralyses  of  orbital 
muscles  in  locomotor  ataxy  occur  in  about  30  to  40  per  cent,  of  the 
cases.  They  usually  appear  in  the  pre-ataxic  stage,  and  even  as  an 
initial  symptom,  and  are  of  two  kinds — namely,  the  transient 
paralysis,  which  lasts  a  few  days  or  weeks,  and  may  recur  ;  and 
the  permanent  paralysis  of  one  or  two  muscles.  Diplopia  is  pro- 
duced by  these  paralyses,  and  is  often  the  symptom  which  first 
induces  the  patient  to  see  his  doctor.  The  sixth  nerve  is  the  one 
most  commonly  paralysed  ;  but  the  third  nerve  is  also  often  para- 
lysed, including  the  branch  to  the  levator  palpebrse,  with  result- 
ing ptosis.  Loss  of  power  of  convergence  is  often  present  in  com- 
mencing tabes,  and  double  exterior  ophthalmoplegia,  as  well  as  double 
sixth-nerve  paralysis,  is  sometimes  seen ;  and  there  can  be  no 
doubt  but  that  all  these  three  conditions,  and  probably  also  some  of 
the  other  oculo-motor  disturbances  in  tabes,  are  often  of  nuclear 
origin.  But  the  orbital  nerves  may,  it  is  found,  undergo  atrophy 
without  their  nuclei  being  altered,  and  probably,  therefore,  some  of 
the  ocular  paralyses*  here  are  due  to  peripheral  neuritis. 

Ocular  ataxy  is  another  not  infrequent  symptom  in  tabes.  It 
is  sometimes  erroneously  called  nystagmus  ;  but  nystagmus  is  a 
constant  oscillatory  motion  of  the  eyeballs,  both  while  the  eyes  are 


CHAP.  XIV.]  SPINAL   DISEASE.  381 

at  rest,  and  when  they  are  looking  at  an  object,  and  is  extremely 
rare  in  tabes.  In  ocular  ataxy,  so  long  as  the  eyes  are  at  rest,  there 
is  no  oscillation  or  twitching ;  but  as  soon  as  an  object  is  carefully 
looked  at,  and  especially  if  followed  when  in  motion,  and  more 
particularly  at  the  end  of  the  latter,  a  slight  twitching  of  the 
eyeballs  is  seen.     It  may  be  found  in  any  stage  of  tabes. 

Pupillary  Alterations. — Miosis  is  the  usual  state  of  the  pupil 
in  tabes,  and  is  held  to  be  due  to  paralysis  of  the  pupil-dilating  fibres 
from  disease  in  the  front  part  of  the  aqueduct  of  Sylvius.  The 
miosis  is  often  extreme,  or  '  pin-hole,'  as  it  is  then  termed  ;  yet 
the  pupil  may  react  to  light  and  on  convergence.  The  pupil  may 
be  of  normal  size  in  tabes  ;  but  mydriasis,  except  as  part  of  a  third- 
nerve  paralysis,  is  rare.  Again,  both  in  the  early  and  later  stages, 
the  pupils  may  be  of  different  sizes. 

The  Argyll  Robertson  pupil  is  an  important  symptom  of  tabes. 
It  consists  in  this,  that,  even  with  normal  or  fairly  good  vision,  the 
pupil,  although  as  a  rule  contracted,  does  not  respond  to  the  stimulus 
of  light  by  further  contraction,  or  but  slightly,  yet  does  become 
more  contracted  on  convergence  of  the  visual  axes  (or  on  accommo- 
dation). Miosis  need  not  necessarily  be  present  with  the  Argyll 
Robertson  pupil ;  the  pupil  may  be  of  normal  size  or  dilated.  The 
symptom  is  one  of  those  most  regularly  found  in  tabes.  It  is  often 
an  early  or  initial  symptom,  and  it  continues  through  all  the  stages 
of  the  disease.  It  is  occasionally  present  in  one  eye  only,  and  is 
sometimes  quite  wanting.  The  pupillary  reaction  on  convergence 
alone  in  advanced  optic  atrophy  must  not  be  mistaken  for  an  Argyll 
Robertson  pupil. 

Neither  the  Argyll  Robertson  pupil  nor  primary  optic  atrophy 
occurs  in  peripheral  neuritis,  a  disease  which  is  liable  to  be  some- 
times mistaken  for  tabes. 

Paralysis  of  Accommodation  without  paralysis  of  the  sphincter 
iridis  is  a  rare  symptom  in  tabes.  It  is  more  common  in  the  late 
than  in  the  early  stages. 

Narrowing  of  the  Palpebral  Fissure,  due  to  a  slight  drooping  of 
the  eyelids,  hardly  to  be  called  ptosis,  sometimes  occurs  in  tabes 
along  with  the  miosis.  It  is  held  to  be  due  to  paralysis  of  the 
sympathetic  (sympathetic  ptosis),  is  usually  binocular,  and  the 
frequency  of  its  occurrence  increases  as  the  disease  advances. 

Twitchings   in   the   Orbicularis   Muscle  for  some   Moments   after 


382  DISEASES   OF   THE   EYE.  [chap.  xiv. 

Closure  of  the  Eyelids  may  sometimes  be  observed  in  tabes.  Similar 
twitchings  may  occasionally  be  seen  in  some  other  nervous  diseases, 
and  even  in  bealtb,  but  less  well  marked.  Probably  their  marked 
character  in  tabes  is  due  to  very  slight  facial  paralysis,  and  the 
consequent  imperfect  power  of  closing  the  eyelids. 

Hereditary  Ataxy  (Friedrich's  Disease)  presents  few  eye-symp- 
toms, a  fact  of  some  diagnostic  importance.  Ocular  ataxy  (p.  380) 
is  the  only  one  which  occurs  with  any  constancy.  Optic  atrophy  is 
of  such  rare  occurrence  in  the  disease,  that  it  can  hardly  be  reckoned 
as  one  of  its  symptoms.  Paralyses  of  orbital  muscles  and  pupil- 
symptom  are  also  rare. 

Myelitis. — Apart  from  the  inflammation  of  its  meninges  (cerebro- 
spinal meningitis),  of  which  mention  has  already  been  made  (p.  377), 
acute  inflammation  of  the  cord  may  be  associated  with  optic  neuritis. 
The  optic  nerve  usually  becomes  inflamed  before  the  spinal  cord 
but  the  myelitis  may  precede  the  optic  neuritis,  or  they  may  occur 
simultaneously.  The  relation  of  the  optic  neuritis  and  myelitis  to  each 
other  is,  doubtless,  nothing  more  than  that  each  is  a  manifestation 
of  the  presence  in  the  system  of  one  and  the  same  toxic  influence. 
Rheumatism,  epidemic  influenza,  and  syphilis  are  amongst  the  causes 
assigned  in  some  cases,  while  in  others  no  cause  could  be  assigned. 
The  field  of  vision  may  be  contracted,  more  rarely  a  central  scotoma 
is  present,  and  the  eyeballs  may  be  painful  on  movement  or  on 
pressure.  If  the  cervical  portion  of  the  cord  is  inflamed,  pupillary 
symptoms — irritation  mydriasis  or  paralytic  miosis — are  apt  to  be 
present. 

Syringomyelia. — Concentric  contraction  of  the  field  of  vision 
without  ophthalmoscopic  changes,  is  the  most  constant  eye-symptom 
in  this  disease.  It  is  not  quite  certain  whether  this  abnormality  of 
the  field  is  due,  at  least  sometimes,  to  attendant  hysteria,  or  is 
always  a  symptom  of  the  organic  disease  as  such.  Atrophy  of  the 
optic  nerve  is  exceptional  and  so  are  paralyses  of  the  orbital  muscles. 
Inequality  of  the  pupils  has  sometimes  been  noted  and  also 
nysta,2;mus. 

Myotonia  Congenita  (Thomsen's  Disease).— In  some  cases  of  this 
rare  disease  the  external  musculature  of  the  eyes  affords  symptoms, 
although  the  intrinsic  muscles  are  never  disordered.  The  opening 
and  closing  of  the  eyelids  may  be  difficult — they  cannot  be  closed  or 
opened  by  one  effort,  successive  jerky  motions  being  required  to 


CHAP.  XIV.]  SPINAL    DISEASE.  383 

effect  closure  or  opening.  As  in  Graves'  disease,  when  the  eyes  are 
open  the  upper  lid  is  apt  to  be  retracted,  and  the  upper  lid  does  not 
readily  follow  the  downward  motions  of  the  eyeball.  Transitory 
amblyopia,  or  even  amaurosis,  has  been  noted  in  some  cases. 

Acute  Ascending  Paralysis  (Landry's  Disease). — Eye-symptoms 
are  rare  in  this  disease,  but  there  may  be  paralysis  of  some  of  the 
orbital  muscles,  paralysis  of  accommodation,  mydriasis,  or  loss  of 
the  light-reflex. 

Injuries  of  the  Spinal  Cord. — The  condition  which  used  to  be 
known  as  railway  spine,  but  which  is  now  better  styled  traumatic 
neurosis,  and  is  due  to  mental  shock  rather  than  to  organic  lesions 
of  the  brain  and  spinal  cord,  is  accompanied  frequently  by  certain 
functional  eye-symptoms,  of  which  the  chief  one  is  a  contraction  of 
the  field  of  vision  similar  to  that  found  in  some  cases  of  hysteria. 
In  those  much  rarer  cases  of  organic  injury  to  the  cord,  or  of  myelitis, 
or  of  haemorrhage  in,  or  inflammation  of,  its  membranes,  following 
on  railway  and  other  accidents,  organic  eye-disease  seldom  results, 
although  optic  neuritis  and  optic  atrophy  were  at  one  time  held  to 
be  frequent  consequences  of  these  injuries.  If  the  lesion  be  in  the 
lower  cervical  region  of  the  cord,  the  pupils  are  apt  to  be  contracted 
from  sympathetic  paralysis. 


Part  IV. 
NERVOUS  AMBLYOPIA,  OR  NERVOUS  ASTHENOPIA. 

The  terms  amblyopia  and  amaurosis  are  used  to  denote  respectively, 
a  defect  in  the  vision,  or  blindness,  for  which  no  assignable  cause 
can  be  detected  in  the  eye  itself.  These  terms  are  in  fact  relics  of 
the  pre-ophthalmoscopic  period,  and  are  now  much  more  restricted 
in  their  use  than  in  former  days. 

Nervous  Amblyopia,  or  Nervous  Asthenopia,  occurs  for  the 
most  part  in  connection  with  three  functional  disorders  of  the  nervous 
system — namely.  Neurasthenia,  Hysteria,  and  Traumatic  Neurosis. 
Many  observers,  it  is  true,  hold  that  these  three  conditions  ought  to 
be  regarded  and  treated  of  as  hysteria,  that  the  term  neurasthenia  is 
quite  superfluous,  while  traumatic  neurosis  is  merely  hysteria  caused 
by  shock.  This  is  not  the  place  to  enter  into  a  discussion  on  this 
question  ;   and  it  need  only  be  said  that  while  these  various  states  of 


384  DISEASES    OF    THE   EYE.  [chap.   xiv. 

the  nervous  system  are  admitted  on  all  hands  to  have  much  in 
common,  and  also  to  merge  insensibly  into  each  other,  yet  typical 
cases  of  each  are  sufficiently  differentiated  to  make  it  justifiable  and 
convenient  to  retain  all  three  in  our  minds,  as  separate  clinical 
entities. 

Neurasthenia  may  be  described  as  abnormal  susceptibility  of  the 
nervous  system  to  fatigue  from  mental  or  bodily  exertion  ;  while  in 
hysteria  the  symptoms  depend  upon  idea,  the  essence  of  hysterical 
conditions  being  that  ideas  too  easily  excite  abnormal  changes  in 
the  organism. 

The  defects  of  vision  which  accompany  these  disorders  are,  like 
all  their  other  symptoms,  purely  functional — i.e.  they  do  not  depend 
on  any  organic  disease  in  the  retina,  or  other  portions  of  the  visual 
apparatus,  but  merely  upon  derangement  of  the  functions  of  these 
parts.  Consequently,  there  are  no  ophthalmoscopic  changes  in  the 
fundus  oculi. 

In  the  following,  the  derangements  of  vision  most  liable  to  be 
found  in  each  condition  will  be  pointed  out,  but  here  it  is  desirable 
in  the  first  instance  to  state  them  in  a  general  way.  Complete 
blindness  of  one  or  both  eyes  may  be  found,  but  is  rare  ;  a  dimin- 
ished, but  fluctuating,  acuteness  of  vision  is  more  common,  the  effort 
or  desire  to  see  well  being  often  the  signal  for  the  acuteness  of  vision 
to  fall,  and  objects  disappear  from  sight  if  looked  at  long.  Attacks 
of  defective  sight,  too,  may  come  on  suddenly  without  any  provoca- 
tion, accompanied  by  positive  scotomata,  and  may  last  for  some 
minutes.  But  the  most  remarkable,  important,  and  characteristic 
symptom  is  concentric  contraction  of  the  fields  of  vision.  It  is 
almost  always  necessary,  in  order  to  ascertain  the  presence  of  this 
symptom,  to  examine  the  fields  with  the  perimeter — no  rougher 
method  will  answer — and  it  is  important  to  use  a  test-object  not 
more  than  5  mm.  square.  Concentric  contraction  of  the  fields  is,  we 
know,  a  symptom  in  optic  atrophy  and  in  glaucoma  ;  but,  while  in 
those  diseases  the  contraction  usually  advances  with  more  or  less 
deep  re-entering  angles  directed  towards  the  fixation  point,  in 
nervous  amblyopia  the  contraction  is  about  equal  in  degree  in  each 
meridian,  and  hence  the  seeing  portion  of  the  field  which  is  left 
presents  a  somewhat  circular  shape  (Fig.  120).  This  shape  of  the 
field  with  normal  ophthalmoscopic  appearances  is  pathognomonic 
of  the  condition.     The  contraction  may  be  but  slight,  or  it  may 


CHAP.  XIV.]  NERVOUS  AMBLYOPIA.  385 


approach  to  within  10°  or  5°  of  the  fixation  point.  It  is  almost 
invariably  present  in  both  eyes,  but  it  is  often  more  marked  in  one 
eye  than  in  the  other. 

Associated  sometimes  with  this  concentric  contraction,  and  some- 
times without  it,  is  a  phenomenon  known  as  the  fatigue  field.  It 
consists  in  this,  that  if  the  test-object  be  brought  from  the  periphery 
towards  the  fixation  point  in  each  meridian  successively,  the  out- 
side limit  of  the  field  comes  nearer  to  the  fixation  point  on  each 
successive  meridian  examined,  without  regard  to  the  part  of  the 
field  in  which  the  examination  is  commenced.  Or,  if  the  test- 
object  be  brought  in  the  horizontal  meridian  from  the  periphery 
on,  say,  the  temporal  side  across  the  field  until  it  disappears  on 
the  nasal  side,  and  the  points  of  entrance  and  of  exit  noted,  and 
the  object  be  immediately  carried  back  on  the  same  meridian  until 
it  disappears  on  the  nasal  side,  and  the  entrance  and  exit  again 
noted,  and  this  manoeuvre  repeated  five  or  six  times  ;  should 
fatigue  be  present,  it  will  be  shown  by  the  points  of  entrance  and 
exit  coming  nearer  and  nearer  to  the  fixation  point  on  each  journey 
— in  short,  the  field  is  becoming  more  and  more  contracted.  This 
method  of  taking  the  field  in  these  cases  is  useful,  too,  as  showing 
whether  at  the  beginning  there  is  any  concentric  contraction  of  the 
field.  These  two  modes  of  examination  are  practically  the  same  ; 
and  the  reason  for  the  form  of  fields  they  are  intended  to  bring 
out  is,  that  the  longer  in  each  case  the  examination  is  continued, 
the  more  fatigued  does  the  nervous  visual  apparatus  (be  it  cerebral 
centre,  or  retina,  or  both)  become,  and  this  exhaustion  is  most 
marked  in  the  periphery  of  the  field.  In  the  normal  state,  the 
boundary  of  the  field  is  not  much  affected  by  the  length  of  the 
examination. 

In  addition  to  contraction  of  the  visual  field,  inversion  of  the 
colour  fields  is  often  present,  the  field  for  red  becoming  the  largest. 
This  sign  may  also  sometimes  be  found  in  cases  of  cerebral 
tumour. 

Ring-form  and  island-like  defects  in  various  parts  of  the  field, 
which  come  and  go,  are  recognised  as  functional  defects,  and  cannot 
be  confused  with  the  continuing  central  scotoma  of  toxic  amblyopia 
due  to  disease  in  the  papillo-macular  fibres.  In  addition  to  the 
defective  sight,  or  contraction  of  the  fields,  or  fleeting  scotomata, 
there  are  often  other  eye-symptoms  present,  such  as  weakness  of 
25 


386  DISEASES   OF   THE   EYE.  [chap.  xiv. 


accommodation,  or  of  the  internal  recti,  or  some  derangement  of  the 
fifth  or  facial  nerves. 

While  functional  derangements  of  vision,  as  distinguished  from 
those  due  to  organic  disease,  are  what  are  here  under  consideration, 
yet  it  is  very  necessary  to  state  that  visual  defects  due  to  organic 
disease  may  sometimes  be  aggravated  by  functional  blindness.  In 
tabes  with  optic  atrophy,  for  instance,  the  contraction  of  the  field 
may  become  suddenly  increased  with  the  occurrence  of  some  mental 
worry  or  intercurrent  general  illness,  and  become  restored  again  to 
its  former  dimensions  with  the  return  to  a  calmer  state  of  mind  or  to 
improved  health.  In  homonymous  hemianopsia,  as  already  men- 
tioned, there  is  often  a  peripheral  contraction  in  the  seeing  side  of 
the  field,  which  can  only  be  due  to  diminished  functional  activity  in 
the  opposite  side  of  the  brain  from  that  in  which  the  disease  is 
situated. 

In  the  three  disorders  of  the  nervous  system  mentioned,  the 
symptoms  may,  in  a  given  case,  remain  confined  to  the  nerves  which 
are  associated  with  the  various  functions  of  the  eye  ;  but  this  is 
rare.  It  is  more  common  to  find  also  symptoms  provided  by  the 
derangement  of  functions  in  other  parts  of  the  nervous  system. 

Nervous  Amblyopia  in  Neurasthenia.— School-children  and  those 
of  that  age  are  very  liable  to  become  neurasthenic.  They  are  brought 
to  the  physician  with  the  complaints  that  the  sight  is  confused,  that 
print  disappears  as  they  look  at  it,  that  reading  causes  the  eyes  to 
smart  and  run  over  water,  and  that  it  brings  on  headache.  If  the 
patient  be  required  to  read  aloud,  he  soon  stops,  complaining  that 
the  words  are  running  into  each  other,  and  the  book  is  then  brought 
closer  to  the  eyes  ;  then  a  few  more  words  are  read,  and  the  book  is 
brought  still  closer,  until,  finally,  it  is  nearly  in  contact  with  the 
nose  ;  and  then  further  attempts  to  see  are  made  by  twisting  the 
head  about,  turning  the  book  towards  the  light,  frowning,  and  so 
on.  Obviously  what  causes  this  difficulty  in  reading  is  a  rapid 
exhaustion  of  the  accommodation.  Insufficiency  of  convergence 
is  also  often  present,  and  would  contribute  to  the  difficulty  of  use  for 
near  work.  The  eyes  are  often  emmetropic,  and  the  amplitude  of 
accommodation  is  normal.  Examination  of  the  fields  may  dis- 
cover them  to  be  concentrically  contracted,  and  the  fatigue  field, 
too,  is  frequently  present.  With  these  asthenic  symptoms  there  are 
often  symptoms  of  exalted  sensibility  of  the  visual  apparatus,  such 


CHAP.  XIV.]  NERVOUS  AMBLYOPIA.  38' 


as  photopsiae  (bright  spots,  coloured  balls,  glittering  surfaces,  etc., 
before  the  eyes),  a  prolonged  continuance  of  the  after-images  of 
objects,  increased  sensitiveness  to  daylight,  and  still  more  so  to 
artificial  light,  and  visual  hallucinations  (heads,  animals,  passing 
shadows,  etc.).  In  the  neurasthenia  of  school-children  eye-symptoms 
often  predominate,  but  other  nervous  symptoms  are  nearly  always 
present,  such  as  hallucinations  of  hearing,  states  of  uncalled-for 
joyous  excitement,  or  of  mental  depression,  or  of  irritability  of 
temper.  Vertigo,  a  tendency  to  weep,  some  loss  of  memory,  and 
insomnia  may  all,  or  any,  of  them  be  present.  The  patellar  reflex 
is  usually  increased.  Patches  of  diminished  sensation  may  be  found 
here  and  there  over  the  surface  of  the  body,  although  completely 
anfesthetic  patches,  or  hemiansesthesia,  are  rare. 

In  school-children  complaints  of  difficulty  in  reading  suggest 
malingering  in  many  instances,  but  it  is  not  wise  to  adopt  this  view 
without  good  grounds  for  it.  An  examination  of  the  fields  may  set 
the  question  at  rest,  for  neither  the  concentrically  contracted  field 
nor  the  fatigue  field  can  be  malingered. 

The  neurasthenia  of  adults  manifests  itself,  so  far  as  eye-symp- 
toms are  concerned,  less  in  the  use  for  near  work  than  is  the  case 
with  school-children.  In  them,  moreover,  the  contraction  of  the 
fields  is  usually  slight,  while  the  fatigue  field  is  well  marked.  These 
patients  complain  of  unpleasant  and  painful  sensations  in  and 
around  the  eye,  such  as  creeping  sensations  and  boring  pains  in  the 
orbit,  stabbings  in  the  eyeball,  a  sensation  as  if  the  eye  w^ere  turned 
round  in  the  head,  and  uneasy  feelings  attending  the  motions  of  the 
globe.  The  eye  may  be  very  painful  on  pressure  at  some  one  spot 
without  apparent  cause  ;  and  there  are  often  uncomfortable  sensa- 
tions of  cold,  burning,  or  dryness  under  the  lids.  If  there  be  an 
error  of  refraction  it  is  difficult  to  find  glasses  with  which  the  patients 
will  be  content,  the  bridge  and  wings  of  the  frames  annoy  them  with 
their  slight  pressure,  while  the  reflection  of  light  from  the  margins 
of  the  eye-pieces  causes  dazzling.  The  patients  are  very  sensitive 
to  any  bright  light.  The  central  acuteness  of  vision  is  usually 
normal,  but  use  of  the  eyes  for  near  work  causes  headache,  often  in 
the  form  of  a  hammering  in  the  temples,  or  a  sensation  of  pressure 
on  the  vortex. 

Treatment. — Tinted  protection  spectacles.  Abstinence  from  use 
of  the  eyes  for  near  work.     A  general  tonic  treatment,  including 


388  DISEASES   OF   THE   EYE.  [chap.  xiv. 


cold  sponge  baths  when  they  can  be  borne,  bracing  air,  plenty  of 
exercise  in  the  open  air  short  of  fatigue,  early  hours,  and  easily 
digested  diet.  As  regards  drugs,  strychnine  and  iron  are  those 
from  which  most  can  be  expected. 

Nervous  Amblyopia  in  Hysteria.— Nervous  amblyopia,  or  ner- 
vous asthenopia,  in  hysteria  is  often  very  similar  to  that  in  the 
neurasthenia  of  school-children,  except  that  the  difficulty  for  near 
work  is  even  greater.  Tonic  blepharospasm  and  partial  paralysis 
of  orbital  muscles  may  accompany  it.  The  blepharospasm  may  be 
slight  and  give  rise  to  a  pseudo-ptosis  which  differs  from  the  paralytic 

Left  Field.  RightField. 

20__     0 


120  \ 


^  ^^  *^  V  ^0  .*  V ,  ^-r .,  z^ ,.  a^^  ^^^^^    ,:,  ^,  ^  ,,-*-^^^  ^  ,,  ,^-^. 


130     ^-n  — 


Fig.  120. — Case  of  Hysteria.  Extreme  and  absolute  contraction  of 
each  field — the  left  more  so  than  the  right — for  white.  Owing  to  the 
small  dimensions  of  the  fields  the  colour  boundaries  could  not  be 
ascertained. 

form  of  ptosis,  in  that  the  eyebrow  is  lowered  instead  of  being  raised 
as  in  the  latter.  Spasm  of  convergence  and  of  accommodation  are 
sometimes  seen.  The  field  of  vision  is  commonly  more  contracted 
in  one  eye  than  in  the  other,  or  the  contraction  may  be  very  marked 
in  one  field,  while  the  other  field  is  normal  or  nearly  so.  In  neuras- 
thenia the  contraction  is  usually  about  equal  in  each  eye.  Inversion 
of  the  colour  fields  is  often  present  in  hysterical  amblyopia,  so  that 
the  field  for  red  is  wider  than  that  for  blue.  Orientation  is  rendered 
more  difficult  by  the  hysterical  than  by  the  neurasthenic  field.  A 
high  degree  of  blindness  or  even  complete  amaurosis  may  attack  a 
neurasthenic  school-child  for  a  few  minutes  ;  but  in  hysteria  such 
attacks,  which  may  occur  in  both  eyes,  but  are  usually  confined  to 


CHAP.  XIV.]  NERVOUS  AMBLYOPIA.  389 

one  eye,  are  likely  to  last  for  weeks,  or  months,  or  longer.  In  the 
amblyopia  of  hysteria,  we  may  find  that  an  eye,  which  cannot  see 
moderately  sized  type,  is  enabled  to  do  so  by  placing  any  plane  glass 
as  spectacles  before  the  eye.  Such  an  occurrence  does  not  mean 
that  the  patient  is  malingering ;  it  shows,  rather,  that  the 
psychical  inhibition  to  the  function  of  sight  in  the  eye  has  been 
withdrawn  by  the  suggestion  provided  by  the  spectacles. 

With  monocular  amblyopia,  or  amaurosis,  there  is  usually  hemi- 
aucesthesia  of  the  same  side  of  the  body  as  the  blind  eye  ;  or,  if 
there  be  merely  contraction  of  the  fields,  there  is  often  hemi- 
ansesthesia  on  the  side  of  the  most  contracted  field. 

The  pupils  vary  much  in  these  cases,  and  even  in  one  and  the 
same  case  from  time  to  time.  They  may  be  normal,  or  wide  and 
immovable,  contracted,  or  of  different  size  in  each  eye,  but  they 
usually  react  to  light  even  though  amaurosis  be  present. 

Nervous  Amblyopia  in  Traumatic  Neurosis.  One  of  the  most 
important  and  most  constant  of  the  symptoms  of  traumatic  neurosis 
is  concentric  contraction  of  the  field  of  vision.  Yet  it  is  often  absent, 
and,  when  present,  is  not  always  sufficiently  typical  in  form  to  enable 
it  to  be  utilised  in  the  diagnosis.  It  is  rarely  so  pronounced  as 
to  interfere  with  orientation,  and  must  be  sought  for  with  the  peri- 
meter to  determine  its  presence.  The  boundaries  for  the  colour- 
fields  are  affected  even  more  than  that  for  white,  and  consequently 
the  tests  for  these  boundaries  may  discover  the  contraction  more 
readily  than  examination  of  the  boundary  for  white.  The  colour 
boundaries  are  often  inverted,  but  colour-blindness  is  seldom  present. 
The  defect  in  the  field  is  usually  to  be  found  in  both  eyes,  and  if 
there  be  hemianaesthesia  it  is  on  the  side  of  the  most  contracted 
field.  It  is  an  important  fact  that  the  contraction  of  the  field  may 
be  the  only  derangement  of  sensation,  either  special  or  general. 
The  contraction  is  liable  to  continue  for  months  or  years,  and  to 
become  more  marked  for  a  time,  as  the  result  of  any  passing  mental 
disturbance.  The  fatigue  field,  too,  is  present  in  some  cases  of 
traumatic  neurosis. 

As  regards  other  ocular  symptoms  in  traumatic  neurosis  :  the 
pupil-reflex  is  usually  normal,  but  is  occasionally  wanting,  and  a 
difference  in  size  of  the  pupils  may  sometimes  be  noted  ;  paralyses 
of  orbital  muscles  are  rare,  but  insufficiency  of  convergence  is 
not  uncommon  ;  sensations  of  sparks,  colours,  and  waviness  before 


390  DISEASES    OF    THE   EYE.  [chap.  xtv. 

the  eyes  are  sometimes  complained  of  ;  photophobia,  and  sensa- 
tions of  dazzling  with  their  resulting  blepharospasm,  may  be  present. 
It  is  not  desirable  to  rest  content  with  one  examination  of  the 
held  of  vision  which  may  prove  negative  in  its  result,  for  it  is  only 
shown  thereby  that  on  that  particular  occasion  the  field  was  normal. 
At  a  later  period  a  defect  may  be  discovered. 


Part  V. 
VARIOUS   FORMS   OF   AMBLYOPIA. 

Transitory  Hemianopsia,  or  Scintillating  Scotoma.— This  affec- 
tion is  characterised  by  (1)  symmetrical  defects  in  the  fields  of  vision, 
usually  of  the  hemianopic  type,  and  (2)  vibrating  or  scintillating 
luminous  sensations,  which  after  a  short  time  disappear,  and  are 
followed  by  an  attack  of  (3)  migraine  which  is  often  unilateral  and 
situated  on  the  side  opposite  to  the  hemianopsia.  In  fact,  the  visual 
troubles  belong  to  the  symptoms  of  migraine. 

The  scintillations  and  defects  in  the  fields,  either  of  which  may 
occur  first,  commence  over  a  small  area,  generally  near  the  centre 
of  the  field,  and  gradually  widen  out  into  a  semicircle  or  horseshoe 
with  the  concavity  towards  the  centre  ;  the  flashing  increases  in 
intensity,  and  often  assumes  a  zigzag  shape,  like  fortifications,  at 
the  periphery  of  the  defect  in  the  field.  This  defect  may  exist  as 
symmetrical  scotomata,  complete  or  partial  homonymous  hemi- 
anopsia, or  even  altitudinal  hemianopsia.  In  some  cases  the  scintil- 
lation may  be  absent,  while  in  others  the  attack  of  migraine  does 
not  follow.  The  ocular  symptoms,  which  last  for  a  period  varying 
from  a  few  minutes  to  half  an  hour,  are  not  accompanied  by  any 
changes  in  the  fundus  oculi,  and  nearly  always  end  in  complete 
recovery,  but  a  few  cases  have  been  recorded  in  which  the  hemi- 
anopsia persisted.  Vertigo,  nausea,  or  sickness,  and  even  slight 
aphasia  sometimes  accompany  the  headache.  The  Ophthalmo- 
scopic appearances  are  normal. 

This  afjfection  occurs  most  frequently  in  intellectually  active 
individuals  ;  fatigue,  long  reading,  and  hunger  have  been  known 
to  bring  on  attacks.  With  advancing  years  the  attacks  tend  to 
diminish.  The  symptoms  are  pro])a])ly  due  to  disturbances  of  the 
circulation  in  the  occipital  lobe. 


CHAP.  XIV.]        VARIOUS  FORMS   OF  AMBLYOPIA.  391 


Treatment  should  be  directed  to  the  cause  of  the  migraine. 
Lying  with  the  head  low,  or  stimulation  of  the  circulation  by 
wine  or  nitro-glycerine  sometimes  cuts  short  an  attack.  Errors  of 
refraction,  or  any  heterophoria  must  be  corrected. 

Congenital  Amblyopia. — This  condition  is  not  very  uncommon. 
Ophthalmologists,  in  the  course  of  their  practice,  meet  with  persons 
in  whom  the  vision  of  each  eye  is  below  the  normal  standard,  even 
with  perfect  correction  of  any  error  in  refraction,  and  who  declare 
that  they  never  have  seen  better,  and  that  their  sight  is  not  getting 
worse.  Still  more  common  is  congenital  amblyopia  in  one  eye 
even  without  strabismus.  It  is  sometimes  hereditary.  As  a  rule 
the  field  of  vision  and  the  colour- vision  are  normal,  but  cases  occur 
in  which  there  is  contraction  of  the  field,  with  defective  colour- 
sight  or  a  central  scotoma.  The  Ophthalmoscopic  Appearances 
are  normal. 

Amblyopia  during  Pregnancy.— The  disturbances  of  vision  which 
occur  during  pregnancy  are  seldom  functional,  with  the  exception  of 
occasional  hysterical  cases.  They  are  for  the  most  part  due  to 
uraemia.  But  occasionally  cases  are  seen  in  which  a  functional 
amblyopia  special  to  the  period  of  pregnancy  occurs.  Whether 
this  is  due  to  toxic  efiects,  or  to  disturbances  of  nutrition,  or  to 
disturbances  of  circulation  has  not  been  determined.  Recovery 
takes  place  after  the  birth,  and  sometimes  even  before  it. 

Reflex  Amblyopia  is  said  to  have  been  observed,  and  chiefly  in  con- 
nection with  irritation  of  the  fifth  pair,  especially  of  its  dental  branches. 
Carious  molar  teeth  are  reputed  to  be  its  frequent  cause,  usually  with 
severe  toothache,  but  sometimes  without  it.  The  defect  of  vision  may 
be  confined  to  the  side  of  the  carious  tooth,  and  is  nearly  always  most 
marked  on  that  side.  It  is  said  that  it  may  be  of  extreine  degree,  vision 
being  reduced  even  to  the  merest  perception  of  light.  It  is  doubtful 
whether  the  amblyopia  in  these  cases  is  truly  reflex. 

More  generally  recognised  than  amblyojDia,  as  the  result  of  toothache, 
are  :  hypersesthesia  of  the  retina,  photophobia,  subjective  sensations  of 
light,  and  diminution  in  the  amplitude  of  accommodation. 

All  these  symptoms,  even  amblyopia  of  the  severest  type,  disappear 
when  the  dental  affection  is  relieved. 

Many  cases  are  on  record  in  which  wounds  of  the  supra-orbital  nerve 
were  looked  on  as  the  cause  of  amblyopia  or  of  amaurosis  ;  but  it  is  by  no 
means  certain  that  an  ophthalmoscopic  examination  would  not  have 
afforded  another  explanation  in  many  of  these  cases.  Yet,  even  nowa- 
days, many  hold  that  wounds  of  the  supra-orbital  region  can  produce 
amblyopia,  as  cases  are  said  to  have  been  cured  by  division  of  the  nerve 
involved  in  a  cicatrix  that  was  tender  on  pressure. 


392  DISEASES   OF   THE  EYE.  [chap.  xiv. 


The  Ophthalmoscopic  Appearances  in  reflex  amblyopia  are  normal. 

Night-blindness.— This  is  a  well-recognised  symptom  of  the 
disease  known  as  Retinitis  Pigmentosa.  We  have  observed  an 
instance  of  congenital  night-blindness  in  five  members  of  a  family 
of  ten  children  without  ophthalmoscopic  signs. 

But  the  condition  to  be  considered  here  is  Acute,  or  Idiopathic, 
Night-blindness. 

The  patients  can  see  well  in  good  daylight ;  but  on  a  very  dull 
day,  or  in  the  dusk  of  evening,  or  by  indifferent  artificial  light,  their 
vision  sinks  very  much  more  than  that  of  persons  with  normal  eyes. 
They  are  then  unable  to  see  small  objects,  w^hich  are  quite  plain 
to  other  people,  and  in  a  still  worse  light  they  fail  even  to  recognise 
large  objects  visible  to  every  one  else.  This  peculiar  visual  defect 
is  due  to  imperfect  adaptation  power  of  the  retina,  and  not  to 
defective  light-sense,  as  is  sometimes  stated. 

Conjunctivitis  and  xerosis  of  the  conjunctiva  (p.  96)  are  often 
present  in  acute  night-blindness.  Some  observers  have  found 
micrococci  and  bacilli  in  the  conjunctiva  in  these  cases,  and  have 
regarded  these  organisms  as  the  cause  of  the  conjunctival  affection. 
It  seems  now  more  probable  that  they  are  merely  secondary  to  the 
xerosis. 

The  connection  between  night-blindness  and  xerosis  conjunctivae 
remains  to  be  explained  ;  but  it  is  likely  that  they  are  both  results 
of  one  cause. 

Acute  night-blindness  is  often  the  result  of  long-continued  daz- 
zling by  very  bright  sunlight,  or  of  lengthened  exposure  to  bright 
firehght  (e.g.  in  foundries),  and  it  is  probable  that  in  many,  if  not 
in  most,  instances  of  this  affection,  defective  nutrition  of  the  system, 
or,  according  to  some,  deficiency  in  the  fat  content  of  the  blood,  plays 
the  chief  role  in  rendering  the  patients  liable  to  it.  In  scorbutus, 
acute  night-blindness  has  been  frequently  seen,  when  the  patients 
have  been  exposed  to  strong  glares  of  sunlight.  It  is  common  in 
an  epidemic  form  in  Russia  during  Lent. 

Treatment  consists  in  protection  from  light — in  short,  in  complete 
darkness  for  a  time — and  then  gradual  return  to  ordinary  daylight ; 
while  the  system  is  to  be  strengthened  by  careful  dietary  and  suit- 
able tonic  medicines,  especially  cod-liver  oil  or  eel  oil. 

Uraemic  Amblyopia. — This  is  most  commonly  seen  in  connection 
with  the  nephritis  of  pregnancy  and  scarlatina,  but  may  occur  in 


CHAP.  XIV.]  VARIOUS   FOBMS    OF   AMBLYOPIA  393 

any  case  of  iireemic  poisoning.  It  is  met  with  in  the  acute  forms  of 
nephritis,  in  which  albuminuric  retinitis  is  not  so  liable  to  occur. 
The  blindness  is  usually  absolute,  and  may  come  on  suddenly,  or 
with  a  short  previous  stage  of  dimness  of  vision.  It  lasts  from 
twelve  hours  to  two  or  three  days,  and  may  recover  completely, 
but  in  some  cases  a  central  scotoma  remains. 

The  O'pJithahnosco'pic  Appearances  are  negative. 

Treatment  can  only  be  directed  to  the  general  condition. 

The  Prognosis  for  vision  is  good,  as  it  always  recovers  if  the 
patient's  life  be  spared. 

Pretended  Amaurosis. — Malingerers  rarely  simulate  total  blind- 
ness of  both  eyes,  and  such  cases  can  often  only  be  detected  by  con- 
stant observation  of  their  actions. 

The  presence  of  pupillary  reflex  is  not  complete  proof,  although 
very  strong  evidence,  that  the  patient  sees,  for  it  would  be  compatible 
with  a  cortical  lesion  causing  total  loss  of  sight. 

The  crossed  diplopia  test  {vide  infra)  may  be  employed  to  detect 
malingerers  of  this  class  ;  for  if  both  eyes  see,  the  one  armed  with 
the  prism  will  rotate  inwards  for  the  sake  of  single  vision,  while 
if  both  eyes  be  blind,  no  such  motion  will  take  place.  Again,  if 
the  malingerer's  own  hand  be  placed  in  various  positions,  and  he 
be  asked  to  look  at  it,  he  w411  in  all  probability  look  in  some  other 
direction  ;  whereas  a  truly  blind  man  usually  makes  a  fair  attempt 
at  directing  his  eyes  towards  his  own  hand. 

Pretended  monocular  amaurosis  can  generally  be  detected  by 
the  Diplopia  Test.  If  the  malingerer  be  made  to  look,  w^th  both 
eyes  open,  at  a  lighted  candle  placed  some  feet  off,  while  a  prism  of 
not  less  than  5°  or  6°,  with  its  base  downwards,  is  held  before  the 
admittedly  good  eye,  he  will  say  he  sees  two  images  of  the  light 
one  over  the  other.  Were  he  blind  of  one  eye  he  would  not  see 
two  images. 

Another  method — the  Crossed  Diplopia  Test — consists  in  holding 
a  prism  of  some  10°  or  12°  with  its  base  outwards  before  the  pre- 
tended blind  eye,  when,  if  it  sees,  it  will  make  a  rotation  inwards  for 
the  sake  of  single  vision,  an  effort  which  a  blind  eye  w^ould  not  make. 

Alfred  Grgefe's  Method.— In  this  test  the  pretended  blind  eye  is 
covered  with  the  surgeon's  hand  from  behind  the  patient,  while  with 
the  other  hand  a  prism  (about  10°),  without  a  metal  rim,  is  held 
base  down  before  the  good  eye,  so  that  its  edge  may  pass  horizontally 


394  DISEASES   OF    THE   EYE.  [chap.  xiv. 


across  the  centre  of  tlie  pupil.  Moiiociilar  double  vision  results,  as 
the  rays  pass  through  the  upper  part  of  the  pupil  normally,  while 
through  the  lower  part  of  it  they  are  refracted  downwards  by  the 
prism.  The  double  images  stand  over  each  other.  If  now  the  hand 
which  excludes  the  pretended  blind  eye  be  rapidly  removed,  while 
at  the  same  moment  the  prism  is  moved  upwards,  so  that  the  entire 
pupil  is  covered  by  it,  a  malingerer  will  still  see  double  images  stand- 
ing one  over  the  other  ;   but  now  the  diplopia  must  be  binocular. 

Harlan's  Test  consists  in  placing  a  trial  frame  on  the  patient's 
nose  wdth  a  very  high  +  lens — say  -\-  li  D — opposite  the  good  eye, 
by  which  means  it  is  excluded  from  distant  vision,  and  a  plane  glass 
— or  a  0'25  D  convex  or  concave  lens,  w^hich  of  course  w^ould  not 
materially  interfere  wdth  its  distant  vision — opposite  the  pretended 
blind  eye.  The  patient  then,  believing  there  is  much  the  same  kind 
of  glass  before  each  eye,  will  read  the  test-types  ;  and  if  it  be  now^ 
desired  to  expose  the  deception,  the  pretended  blind  eye  is  excluded 
from  sight,  and  the  malingerer  w^ill  then  be  unable  to  read  the  test- 
types. 

Snellen's  Coloured  Types  may  also  be  used  for  this  purpose. 
These  types  are  printed  in  green  and  red.  If  a  person  be  really  blind 
of  one  eye,  he  will,  of  course,  see  both  the  green  and  the  red  letters 
W'ith  the  good  eye.  But  if  a  green  glass  be  held  before  the  good  eye, 
the  rays  from  the  red  letters  will  be  excluded,  and  he  wall  now  only 
see  the  green  letters  ;  or  with  a  red  glass  the  red  letters  alone  will 
be  seen.  A  malingerer  may  be  detected  by  holding  before  his  ad- 
mittedly good  eye  a  green  glass  ;  and  if  he  now^  still  see  the  red 
letters,  it  must  be  that  he  does  so  wdth  the  so-called  blind  eye.  A 
good  modification  of  this  test  is  Haselberg's  test  types,  of  which  the 
letters  are  composed  of  black  and  red  portions.  The  diploscope 
and  diaphragm  tests  (chap,  xvii.)  are  also  useful. 

It  is  well  to  have  this  variety  of  tests,  in  order  that  they  may  be 
used  to  corroborate  each  other. 

Erythropsia  {(pvOpos,  red) — Red  Vision.  ^lany  cases  of  this  remark- 
able affection  have  been  observed ;  indeed,  it  will  have  come  under 
the  notice  of  nearly  every  ophthalmic  surgeon  of  any  experience.  The 
majority  of  the  cases  have  been  subjects  of  successfvil  cataract  operations, 
whilst  the  remainder  have  possessed  normal  eyes.  It  is  generally  the 
result  of  prolonged  exposure  to  the  light,  especially  with  dilated  pupils.  In 
some  cases  the  red  vision  remains  only  a  few  minutes,  and  does  not  again 
return  ;    Mhilst  in  others  it  appears  every  day  for  a  short  time,  for  weeks 


CHAP.  XIV.]        VARIOUS   FORMS   OF  AMBLYOPIA.  395 

or  months  ;  and,  again,  in  others  it  continues  for  several  days,  and  then 
disappears  for  good  or  recurs  at  intervals.  In  the  aphakic  cases  it  does 
not  usually  appear  for  weeks  or  months  after  the  removal  of  the  cataract, 
and  the  interval  may  be  as  long  as  two  years.  During  the  attacks  the 
patients  see  all  objects  of  a  deep  red  colour,  and  occasionally  of  a  purple 
or  violet  hue.  In  no  instance  is  the  acuteness  of  vision  affected  either 
during  or  after  the  attacks. 

A  quite  satisfactory  explanation  for  the  affection  has  not  yet  been 
offered.  Possibly  it  is  due  to  over-excitation  of  the  visual  nervous  appar- 
atus— it  may  be  of  the  visual  centre,  or  of  the  retina — caused  by  exposure 
of  the  eye  to  light  which  is  rich  in  ultra-violet  rays,  as  in  high  mountain 
altitudes,  along  with  other  favouring  circumstances,  especially  general 
over-excitement  of  the  body  or  mind.  The  normal  crystalline  lens  absorbs 
the  greater  part  of  the  ultra-violet  rays  which  are  present  in  the  daylight 
at  ordinary  altitudes.  Consequently  the  retina  of  an  eye  which  has  been 
operated  on  for  cataract  is  deprived  of  this  protection,  and  is  liable  to  the 
irritation  caused  by  these  rays. 

Treatment  seems  to  have  but  little  effect.  Protection  of  the  eyes  from 
light  has  not  been  of  use.  Bromide  of  potassium  internally  seems  to 
have  done  some  good  in  those  cases  where  it  was  tried. 


CHAPTER  XV. 
ELEMENTARY   OPTICS. 


§  1.  The  light  from  a  luminous  point  travels  in  all  directions  in  diverging 
straight  lines  which  are  called  rays.  The  angle  between  the  outermost 
rays  which  pass  through  an  aperture  (A  B,  Fig.  121),  or  fall  on  a  given 
surface,  is  the  measure  of  the  divergence  of  the  rays.  This  divergence 
diminishes  as  the  distance  of  the  luminous  point,  from  the  surface  on  which 
the  light  falls,  increases  until  it  finally  becomes  so  small  that  the  rays 
may  be  considered  to  be  parallel.  In  a  strict  mathematical  sense,  rays 
can  only  be  parallel  .when  the  luminous  point  from  which  they  come  is 
at  an  infinite  distance  ;   but,  in  ophthalmological  practice,  rays  proceeding 

from  any  point  at  a  dis- 
tance of  6  metres,  or  more, 
from  the  eye  may  be  re- 
garded as  parallel  when 
they  reach  the  pupil. 
Under  natural  conditions, 
rays  entering  the  eye  are 
either  divergent  (objects 
nearer  the  pupil  than  6  m.) 
or  parallel ;  but  they  are 
never  convergent,  unless 
rendered  so  by  artificial 
means  (lenses,  mirrors). 

§  2.  When  light  falls 
on  an  opaque  object,  some 
of  the  rays  are  absorbed,  some  are  reflected  in  an  irregular  or  diffuse 
manner,  rendering  the  object  visible,  while  others  are  regularly  reflected 
according  to  the  amount  of  polish  on  the  surface  of  the  object,  but  none 
pass  through  it.  When  the  object  is  transparent,  the  majority  of  the  rays 
pass  through,  but  are  bent  or  refracted  if  the  velocity  of  the  light  be 
diminished  in  its  passage  through  the  object — that  is  to  say,  if  the  optical 
density  of  the  latter  be  greater  than  that  of  the  surrounding  medium. 

§  3.  Refraction,  then,  is  the  deviation  which  a  ray  of  light  undergoes 
when  it  passes  from  one  homogeneous  transparent  medium  into  another 
of  different  density.  The  only  rays  which  are  not  refracted  are  those 
perpendicular  to  the  surface  (A  B,  Fig.  122).  All  others  are  deviated  to- 
wards the  perpendicular  when  passing  from  a  rarer  into  a  denser  medium, 
and  away  from  the  perpendicular  when  travelling  in  tlie  opposite  direction. 

396 


Fig.  121 . — The  rays  f  rom  D,  which  is  further 
from  A  B  than  C,  have  a  smaller  angle  of 
divergence.  The  parallel  rays,  E  E,  are  sup- 
posed to  come  from  a  point  infinitely  distant. 


CHAP.    XV. 


ELEMENTARY   OPTICS. 


397 


In  Fig.  122  the  incident  ray,  I  H,  travelling  from  the  rarer  medium  (air) 
into  the  denser  medium  (glass),  is  bent  towards  the  perpendicular,  P, 
in  the  direction  H  R,  and  would  continue  in  this  path  as  long  as  it  remained 
in  the  denser  medium  ;  i  is  the  angle  of  incidence  and  r  the  angle  of  re- 
fraction. If  the  ray  R  H  were  to  pass  back  in  the  opposite  direction 
from  the  glass  into  air,  it  would  be  deviated  away  from  the  perpendicular, 
in  the  direction  H  T.  The  path  of  the  ray,  therefore,  is  the  same  in  either 
direction. 

§  4.  Index  of  Refraction. — The  more  optically  dense  a  medium  is, 
the  greater  is  its  refractive  power.  The  relative  refractive  power  of  a 
given  substance  is  called  the  index  of  refraction  of  the  substance,  air 
being  generally  taken  as  the  unit.  A  medium,  therefore,  having  a  greater 
density  than  air  will  have,  as  index,  a  number  greater  than  unity  ;  the 
index  of  crown  glass,  for  instance,  is  To.  The  cornea  and  the  vitreous 
humour  have  the  same  index  as  water,  namely  r33,  while  that  of  the 
crystalline  lens,  as  a  whole,  is  r43. 
The  refractive  power  depends  on  the 
difference  between  the  indices  of  the 
two  media  ;  for  example,  in  the  eye 
the  cornea  has  a  greater  effect  than 
the  lens,  although  it  has  a  lower  re- 
fractive index  than  the  latter,  because 
the  difference  between  air  and  the 
cornea  is  greater  than  that  between 
the  media  (aqueous  and  vitreous)  and 
the  lens  which  lies  in  them. 

§  5.  Plane  Parallel  Surfaces  (Plane 
Glass)  bounding  a  transparent  medium 
cause  merely  a  lateral  displacement  of 
the  rays  without  changing  their  direc- 
tion, if  the  first  and  last  media  are 
the  same.  In  Fig.  122,  C  D  F  G  may 
be  taken  to  represent  a  piece  of  glass 
with  parallel  sides  C  D  and  F  G,  with 

air  on  each  side.  When  the  emergent  ray,  R  E,  passes  out  again  into  the 
air  it  is  refracted  away  from  the  perpendicular,  P',  and  as  the  angles 
i  and  r'  are  equal,  and  the  perpendiculars  P  and  P'  are  parallel,  the  ray 
E  R  is  parallel  to  its  original  path  I  H,  and  suffers  only  a  lateral  dis- 
placement, which  increases  with  the  thickness  of  the  plate.  But  the  rela- 
tive direction  of  the  rays  is  not  changed  ;  they  retain  the  parallelism, 
divergence,  or  convergence,  which  they  possessed  before  their  passage 
through  the  plate  ;  hence  no  images  are  formed  by  plane  glass,  and  ob- 
jects seen  through  it  are  unaltered  in  size  and  shape. 


Fig.  122. — Refraction  at  a 
plane  surface.  The  siu'faces  C  D 
and  F  G  being  parallel,  the 
emergent  R  E  is  parallel  to  the 
incident  ray  I  H. 


Prisms. 
§  6.  Prisms  are  refracting  media  limited  by  plane  surfaces  which 
are  inclined  at  angle,  as  in  Fig.  123.       The  thin  edge  is  called  the 


398 


DISEASESI^OF   THE  EYE. 


[chap.    XV 


iVpex,  a  is  the  Refracting  Angle,  wliile  the  thick  part'opposite  the 
apex  is  the  Base.     In  passing  through  a  prism  a  ray  of  light  under- 


FiG.  123. — Refraction  by  a 
prism.  The  rays  from  O  are 
displaced  towards  the  base,  but 
O  appears  to  an  observer  at  R  to 
be  displaced  towards  the  apex. 


Fig.  124. — Showing 
parallelism  or  diverg- 
ence of  rays  unaltered 
by  their  passage 
through  a  prism. 


Fig.  12 


goes  a  double  refraction  towards  the  base.  The  ray  0  is  deflected 
towards  the  perpendicular  on  entering  the  prism,  and  away  from  it 
on  passing  into  the  air  at  the  side  B  A,  the  deviation  being  towards 
the  base  in  each  case. 

An  obiect  seen  through  a  prism  seems  to  be  displaced  towards  the 
apex  ;  for  example,  an  eye  placed  at  R  receives  the  ray  E  R  coming 
from  0,  and  imagines  it  to  be  at  0'  in  the  prolongation  of  R  E. 
The  deviation  which  the  ray  0  has  undergone  is  shown  by  the  angle 
d  (angle  of  deviation).  In  prisms  made  of  crown  glass,  with  an 
index  of  refraction  of  1*5,  the  angle  of  deviation  is  equal  to  half  the 
angle  of  the  prisms.  Fig.  124  shows  that,  as  in  plane  glass,  the  rela- 
tion of  the  rays  to  each  other  is  unaltered 
in  their  passage  through  a  prism. 

§  7.  Numbering  of  Prisms.— Prisms 
are  numbered  according  to  the  size  of 
the  refracting  angle  {a,  Fig.  123),  which  is 
expressed  in  degrees  ;  we  speak  of  prisms 
of  r,  2°,  etc. 


CT 
-One  centrad  =^5-. 
R 

AT  = 

One     prism     dioptre     -:^ 

1  R 

1  cm. 


100  cm.' 


This  method  ut  numeration  is  not  quite 

accurate,  because  the  deviation  depends,  not 

only  on  the  angle  of  the  prisms,  but  also  on 

the  refractive  index  of  the  glass  composing 

it ;    hence,  two    prisms  having  the    same  number  will    not  produce  the 

same  amount  of  deviation,  or  be   of  the  same  strength,  if  the  kinds  of 


CHAP.    XV,] 


ELEMENTARY   OPTICS. 


399 


glass  of  which  they  are  made  have  different  refractive  powers.  It  has, 
therefore,  been  proposed  to  number  them  according  to  the  angle  of 
deviation  (d,  Fig.  123),  expressed  either  in  Centrads  or  in  Prism-Dioptres,  a 
centrad  being  a  deviation  {d,  Fig.  125),  the  arc  (C  T)  of  which  is  ^}jy  of  the 
radius,  while  in  the  prism-dioptre  it  is  the  tangent  (A  T)  which  is  the  -f^jf 
of  the  radius  (Fig.  125).  The  three  methods  are,  however,  equivalent 
for  all  practical  purposes.  The  simplest  plan  would  be  to  indicate  the 
deviation,  and  not  the  angle  of  the  prism,  in  degrees. 

§  8.  Recognition  of  a  Prism  and  the  Base-apex  Line.— Prisms 

used  in  ophthalmic  practice  are  usually  cut  round  for  convenience 
of  placing  in  trial  frames,  but  the  thick  base  and  thin  apex  are 


Fig.  126.— Prism  hori- 
zontal, vertical  line  only 
displaced. 


D 

Fig.  127.— Prism  held 
obliquely,  both  vertical  and 
horizontal    lines    displaced. 


sufficient  to  distinguish  them  from  lenses  or  plane  glass.  In  weak 
prisms  this  is  not  so  evident,  but  they  can  always  be  recognised  by 
the  displacement  which  they  cause  when  an  object  is  seen  through 
them,  by  quickly  putting  the  prism  up  before  one  eye,  the  other 
being  closed,  or  if  the  prism  be  rotated  before  the  eye,  an  object  seen 
through  it  will  be  observed  to  move  in  a  circle,  following  the  dis- 
placement of  the  apex.  Figs.  126  and  127  show  a  simple  method  of 
selecting  the  displacement,  and  at  the  same  time  of  ascertaining  the 
exact  position  of  the  apex  and  base.  The  prism  is  held  at  a  short 
distance  from  the  eye  opposite  two  crossed  lines,  vertical  and  hori- 
zontal (the  bars  of  a  window-sash,  say),  so  that  they  can  be  seen 
outside  the  edge  of  the  glass  as  well  as  through  it.  If,  as  in  Fig.  126, 
the  apex  and  base,  A,  and  B,  are  exactly  horizontal,  then  the  portion 


400 


DISEASES   OF    THE  EYE. 


[chap.  XV 


of  the  vertical  line  C  D  seen  through  the  glass  will  alone  be  dis- 
placed towards  the  apex  ;  but  if  the  prism  be  oblique  both  lines 
will  be  displaced  as  in  Fig.  127. 

§  9.  Effect  of  a  Prism  on  Binocular  Vision.— When  a  prism  is 
placed  before  one  eye,  both  eyes  being  open,  the  immediate  effect  is 
to  cause  double  vision  or  diplopia,  which  either  persists,  or  is  over- 
come by  an  effort  of  one  of  the  orbital  muscles.  In  Fig.  128,  the 
image  of  the  object,  0,  falls  on  the  macula  lutea,  M,  in  the  left  eye 
(L),  but  instead  of  falling  on  the  macula,  M,  in  the  right  eye  (R)  it  is 
displaced  by  the  prism,  towards  the  base  of  which  it  is  refracted  to 

a  point  B  on  the  retina,  which  is 
not  physiologically  identical  with 
M  in  the  left  eye,  and  0  now 
appears  to  the  right  eye  to  be  at 
0',  in  the  prolongation  of  B  P, 
and  the  patient  sees  two  images, 
one  with  each  eye.  An  uncon- 
scious effort  is  then  made  by 
the  patient  to  bring  the  macula, 
M,  into  the  position  B.  This  is 
accomplished  by  the  action  of 
the  Ext.  Rectus  (R  E),  and  thus 
single  vision  is  again  obtained. 
If  desired,  by  increasing  the 
strength  of  the  prism  until  the 
diplopia  can  no  longer  be  overcome,  the  strength  of  the  muscle, 
in  this  instance  the  Ext.  Rectus,  can  be  estimated.  It  will  be 
observed  also,  that  when,  in  order  to  correct  the  diplopia,  the  axis 
of  the  eye  has  moved  into  the  position  P  B,  the  convergence  of  the 
eyes  is  diminished,  and  therefore  the  effort  of  the  internal  rectus 
muscle  must  to  a  certain  extent  be  relieved.  From  this  it  follows, 
that  the  muscle  towards  the  apex  of  the  prism  is  brought  into 
action,  while  the  muscle  towards  the  base  is  relieved.  The  rotatory 
prism,  composed  of  two  prisms  of  equal  strength,  in  contact,  and 
rotating  in  opposite  directions,  is  a  useful  instrument  for  measuring 
purposes,  as  by  its  aid  values  of  from  0°  up  to  the  strength  of  both 
prisms  combined  can  be  obtained  gradually.  Maddox's  double 
prism  is  also  very  convenient  for  producing  diplopia  (see  Latent 
Deviations,  chap.  xvii.). 


Fig.  128. — Binocular  diplopia  pro 
duced  by  a  prism. 


CHAP.    XV. 


ELEMENTARY    OPTICS. 


401 


§  10.  Uses  of  Prisms. — 1.  By  the  production  of  diplopia,  prisms 
can  be  used,  {a)  to  test  the  strength  of  muscles,  {h)  to  detect  latent 
deviations  or  insufficiencies  of  muscles,  (c)  to  strengthen  weak  muscles 
by  exercise,  {d)  to  test  binocular  vision,  (e)  to  detect  feigned  blind- 
ness of  one  eye.  2.  For  the  purpose  of  correcting  or  measuring  the 
diplopia  in  paralysis,  or  insufficiencies  of  orbital  muscles. 

§  11.  Prescribing  of  Prisms. — In  practice  prisms  of  more  than 
four  degrees  can  rarely  be  worn  by  patients,  owing  chiefly  to  the 
weight  and  colour  effects  of  higher  numbers.  The  position  of  a  prism 
placed  before  an  eye  is  indicated  by  reference  to  its  base,  e.g.  Pr.  3° 
base  up,  down,  in,  or  out,  as  the  case  may  be. 


Lenses. 

§  12.  A  lens  is  a  portion  of  a  transparent  refracting  medium 
bounded  by  two  surfaces,   one  or  both   of  which  are  curved.     It 


Fig.  1 29. — Convergent 
effect  of  a  convex  or  + 
lens.    F,  principal  focus. 


Fig.      130. — Divergent 
effect  of  a  concave  or  — 
lens.     F,  principal  focus. 


may  be  spherical,  or  cylindrical,  or  it  may  be  compound — that  is  to 
say,  spherical  on  one  surface  and  cylindrical  on  the  other. 

§  13.  Spherical  Lenses  are  bounded  by  spherical  surfaces,  and 
therefore  their  action  is  the  same  in  all  meridians  ;  they  are  either 
convex  or  concave.  Convex  spherical  lenses  may  be  regarded  as 
composed  of  prisms  with  their  bases  together  (Fig.  129)  and  are 
thickest  in  the  centre.  They  converge  parallel  rays  of  light,  and 
bring  them  to  a  point  or  focus.  Concave  lenses,  on  the  other  hand, 
are  like  prisms  with  their  apices  together  (Fig.  130),  and  are  thinnest 
in  the  centre.  They  cause  parallel  rays  of  light  to  diverge.  Convex 
lenses  are  positive,  and  are  indicated  by  the  sign  +  (plus).  Concave 
lenses  are  negative,  and  marked  with  the  sign  —  (minus).  The 
26 


40: 


DISEASES   OF    THE   EYE. 


[cHAr.   xv. 


former  placed  in  front  of  the  eye  add  to  its  refractive  power,  the 
latter  diminish  it.     Fig.  131  shows  the  different  kinds  of  spherical 


Convex  or -i-. 

Concave  or — 

Plano-convex 

^        ^ 

r^-^ 1    Pinnn-concnvp. 

Bl  convex 

<c_> 

^ ^->J  Biconcave 

Con  V  ex  m  cms  ciis 

"^=r ^• 

^^====::^    Concave  meniscus. 

iperiscopicieris) 

pertscoptc  lens) 

Fic;,    131. — Different  forms  of  spherical  lenses. 

lenses  in  use.  In  the  convex  meniscus,  the  convex  surface  has 
a  shorter  radius  of  curvature  than  the  concave  ;  whereas  in  the  con- 
cave meniscus,  the  concave  surface  has  the  smaller  curve.  Meniscus 
lenses  are  also  called  periscopic  (^epi,  around',  o-Koirdv,  to  look), 
because  (with  the  concave  surface  towards  the  eye)  they  produce 
less  distortion  towards  their  edges,  and  consequently  permit  a 
greater  excursion  of  the  eye. 

§  14.  Axes  of  Spherical  Lenses. — The  Principal  Axis  of  a  spherical 
lens  (P  A,  Fig.  132)  is  the  line  joining  the  centres  of  curvature  of  the 
surfaces,  and  the  point  0  in  the  centre  of  the  lens  on  the  principal 
axis  is  known  as  the  Optical  Centre.     Any  ray  passing  through  the 

optical  centre,  except  along 
the  principal  axis,  is  called 
a  Secondary  Axis,  and  it 
emerges  parallel  to  its  origi- 
nal direction  (N  E  is  parallel 
to  S  S').  In  thin  lenses  the 
slight  displacement  may  be 
neglected,  and  the  second- 
ary axes  may  be  considered 
to  pass  through  the  optical 
centre  without  any  devia- 
tion. These  statements 
apply  to  both  convex  and  concave  lenses. 

§  15.  Principal  Focus  of  Convex  Spherical  Lenses.— The  point  to 
which  parallel  rays  of  light  converge  after  passage  through  a  convex 


Fig. 


132. — Primary  and  secondary  axes 
of  a  lens. 


CHAP.    XV. 


ELEMENTARY    OPTICS. 


403 


Fig.  133. — Principal  focus 
(P  F)  and  focal  length  of  a 
lens , 


The  stronger 


the  lens  the 


lens  is  called  the  Principal  Focus  of  the  lens,  and  the  distance  of 

this  point  from  the  lens  is  its  focal  length  (Fig.  133).     Rays  of  light 

diverging    from    the    principal    focus 

pass   out   parallel   on   the   other   side 

of   the   lens.     Rays   {a   c,   Fig.    133), 

parallel    to    the   principal    axis,    have 

their  focus  on  this  axis,  while  those 

which    are    parallel    to    a    secondary 

axis  (A  8,  Fig.  134)  are  brought  to  a 

focus    on    the    secondary    axis    at    a 

point  (S),  where  it  cuts  the  perpen- 
dicular    line     passing     through     the 

principal  focus  (principal  focal  plane). 

more  the  rays  are  refracted,  and  therefore  the  shorter  is  the  focal 

length  (Fig.  135.) 

§  16.  Conjugate  Foci  are  foci 
which  are  so  related  that  rays  from 
one  of  them  pass  to  the  other  and 
vice  versa.  For  instance,  the  con- 
jugate focus  of  parallel  rays  (or  in- 
finity) is  the  principal  focus,  and 
the  latter  is  again  the  conjugate 
focus  of  infinity. 

§  17.  Real,  or  Positive,  Conjugate 
Focus  of  a  Convex  Lens. — We  have 
now   to    consider   what   happens   to 

rays   which   diverge   from   points   on   either   side    of   the   principal 

focus  ;    namely,  points  farther  from,  or  nearer  to,  the  lens  than  the 

principal  focus.     In  Fig.  136  the  rays  from 

the  point  1  farther  from  the  lens  than  the 

principal  focus  F,  converge  to  1',  bej^ond 

F,  on  the  other  side  of  the  lens,  and  form 

an  image  there,  which  is  real  and  can  be 

received  on    a  screen.      When  the  point 

from  which  the  rays   diverge   approaches 

nearer  to  F,  say  at  2,  then  the  conjugate 

focus    moves    farther   away  to    2\  until, 

when  the.  point  reaches  the  principal  focus  F,  the  conjugate  focus 

has  moved  away  to  infinity  and  the  rays  are  parallel.     It  will  be 


Fig.  134.— Rays  A  and  B, 
parallel  to  the  secondary  axis 
A  S,  unite  in  the  focal  plane 
F  P  at  S. 


Fig.  1 35. — The  stronger 
lens  (2)  has  a  shorter 
focus,  F  2. 


404 


DISEASES    OF    THE   EYE. 


[chap.    XV. 


noticed  that  in  this  rase  the  conjugate  foci  are  on  opposite  sides  of 
the  lens,  but  that  thev  move  in  tlie  same  direction. 


Fig.    130. 


or   positive,    conjugate   foci    of    a    convex    lens. 


Fig.  137. — Virtual,  ornegative,  conjugate 
foci  of  a  convex  lens. 


§  18.  Virtual,  or  Negative,  Focus  of  a  Convex  Lens.— When  rays 
proceed  from  a  point  nearer  to  the  lens  than  the  principal  focus  P\ 
the  angle  of  divergence  being  greater  than  at  F.  the  lens  is  not 
sufficiently  strong  even  to  render  them  parallel,  and  they  therefore 

continue  to  diverge  after 
their  passage  through  the 
lens,  but  not  so  much  as 
before.  In  Fig.  137.  the 
rays  coming  from  P,  inter- 
nal to  the  principal  focus, 
F,  are  rendered  by  their 
passage  through  the  -lens, 
L,  less  divergent  than  be- 
fore ;  but,  being  divergent,  they  cannot  come  to  a  focus.  To 
an  observer  at  C,  however,  looking  through  the  lens,  the  rays  A 
and  B  would  seem  to  come  from  a  point  P',  in  the  direction  of 
their  prolongation.  P'  is  the  conjugate  focus  of  P,  but  it  is  virtual 
as  opposed  to  real,  and  is  negative,  or  on  the  same  side  of  the  lens 
as  P.  If  we  consider  the  rays  as 
travelling  in  the  opposite  direc- 
tion, A  and  B  with  a  convergence 
towards  P'  will  be  focussed  at  P. 

§  19.  Foci  of  Concave  Spherical 
Lenses. — A  concave  lens  renders 
parallel  rays  divergent.  In  Fig.  138, 
rays    A    and    B,    parallel    to    the 

principal  axis  P  X,  diverge  as  if  they  came  from  F,  which  is  the 
principal  focus  of  the  lens.  Kays  from  a  near  point  will  be  rendered 
still  more  divergent,  and  will  appear  to  proceed  from  a  point  still 


Fio.  138. — Principal  focus  of  a 
concave  lens. 


CHAP.    XV.] 


ELEMENTARY    OPTICS. 


405 


closer  to  the  lens  than  the  principal  focus,  F  ;  but,  in  all  cases, 
the  conjugate  focus  will  be  apparent  or  virtual,  and  also  negative, 
or  on  the  same  side  of  the  lens  as  the  point  of  light.  Convergent 
rays  are  rendered  parallel  by  a  concave  lens  if  they  converge  to- 
wards the  principal  focus  on  the  other  side  of  the  lens,  and  divergent 
if  the  point  towards  which  they  converge  is  farther  from  the  lens 
than  the  principal  focus.  They  still  remain  convergent,  but  less  so 
than  before,  if  the  point  towards  which  they  converge  is  closer  to 
the  lens  than  the  principal  focus. 

§  20.  Images  formed  by  Spherical  Lenses  consist  of  foci  each  of 
which  corresponds  with  a  point  in  tlie  object,  and  of  which  it  is  the  con- 
jugate focus.  The  image  is  real  when  the  rays  forming  it  actually  meet 
and  can  be  received  on  a  screen  ;  it  is  virtual  when  it  does  not  in  reality 
exist,  but  is  formed  by  the  imaginary  backward  prolongation  of  the  rays, 
and  can  only  be  seen  by  looking  through  the  lens. 


Fig.   139. — Image  of  a  given  point  O  formed  by  a  convex  lens. 


§  21.  Method  of  finding  the  Position  and  Size  of  an  Image  formed  by 
a  Spherical  Lens. — In  order  to  find  the  position  of  the  image  of  a  point, 
say  of  O,  Fig.  139,  formed  by  a  lens,  first  draw  the  secondary  axis  O  I, 
which  passes  through  the  optical  centre  without  deviation.  The  image 
will  be  formed  on  this  axis  at  a  point  where  the  other  rays  proceeding 
from  O  intersect  it.  Two  other  rays  (the  paths  of  which  are  known) 
can  be  utilised  :  O  A  parallel  to  the  principal  axis  will  pass  through  the 
principal  focus  Fo,  and  the  image  of  O  will  be  at  I,  where  A  I  meets  O  I, 
or  I  can  be  found  by  means  of  the  ray  O  C,  which  passes  through  the 
principal  focus,  Fi,  and  therefore  becomes  parallel  to  the  principal  axis, 
taking  the  direction  C  I.  In  the  following  examples,  the  ray  O  A  will 
be  used. 

§  22.  Real  Inverted  Image  formed  by  a  Convex  Lens. — When  an 
object  is  farther  from  the  lens  than  the  principal  focus,  an  inverted  image 
is  formed  on  the  opposite  side  of  the  lens,  as  in  Fig.  140,  and  the  image  is 
equal  to  the  object  A  C,  and  at  the  same  distance  from  the  lens,  if  the  object 
be  at  twice  the  focal  distance  from  the  lens.  The  image  is  larger  if  the 
object  be  closer  than  2F  (e  d  is  the  image  of  D  E),  and  smaller  if  it  be 
farther  than  2F  (D  E  is  the  image  ii  e  d  be  the  object).     The  closer  the 


40G 


DISEASES   OF    THE   EYE. 


[chap.   XV. 


object  is  to  the  principal  focus,  the  larger  the  image.     It  is  in  this  way  that 
the  image  is  produced  in  the  indirect  metliod  of  ophtlialmoscopy. 

§  23.  Virtual,  Erect,  and  Magnified  Image  formed  by  a  Convex  Lens. 
When  the  object,  C  D  (Fig.  141)  is  closer  to  the  lens  than  the  principal 
focus  Fi,  an  erect,  magnified  virtual  image,  c  d,  can  be  seen  on  looking 
at  the  object  through  the  lens.  As  the  object  approaches  the  lens,  say 
to  N  P,  the  image,  n  p,  becomes  smaller  ;    in  other  words,  the  virtual, 


Fig.  140. — Real  inverted  image  formed  by  a  convex  lens  when  the 
object  is  farther  from  the  lens  than  the  principal  focus. 

like  the  real  inverted  image,  increases  in  size  the  nearer  the  object  is  to 
Fi.     It  is  in  this  way  that  a  convex  lens  is  used  as  a  magnifying  glass. 


Fig.  141. — Virtual  erect  and  magnified  image  formed  by  a  convex 
lens,  when  the  object  is  closer  to  the  lens  than  the  principal  focus. 


§  24.  Images  formed  by  Concave  Lenses  are  always  erect,  virtual  and 
diminished.  The  nearer  the  object  is  to  the  lens  the  larger  the  image. 
In  Fig.  142  the  point  c  or  image  of  C  is  found  at  the  intersection  of  S  R 
(prolonged  back  to  the  principal  focus,  F)  with  the  secondary  axis  COX, 
and  d  e  is  the  image  of  D  E. 

§  25.  Optical  Defects  of  Lenses. — 1.  Spherical  Aberration.  In 
§  15  it  is  stated  that  parallel  rays  after  passing  through  a  lens  unite 
in  one  point  at  the  principal  focus.  Now  this  is  practically  the  case, 
if  only  a  small  area  of  the  lens,  near  the  axis,  be  utilised,  say,  by 


CHAP.  XV.]  ELEMENTARY   OPTICS.  407 


means  of  a  '  stop  '  or  diaphragm,  but  as  more  of  the  periphery  of 
the  lens  is  taken  in,  the  rays  become  increasingly  refracted,  and 


Fig,     142. — Virtual    erect    and    diminished    imago    formed 
by  a  concave  lens. 

cut  the  axis  correspondingly  nearer  to  the  lens  (Fig.  143).  Hence 
when  a  larger  portion  of  the  lens  is  used,  the  image  is  rendered 
indistinct.  Spherical  aberra- 
tion is  present  in  the  eye, 
although  to  a  certain  extent 
corrected  by  contraction  of 
the  pupil. 

2.  Chromatic  Aberration. 
— The  spectral  colours,  of 
which    white    light    is    com-  Fig.  143. 

posed,  are  refracted  in  differ- 
ent degrees  by  a  lens,  the  red  rays  being  the  least  and  the  violet 
the  most  refrangible.  This  tends  to  give  a  coloured  border  to 
the  images  formed  by  the  lens.  This  phenomenon  is  known  as 
chromatic  aberration.  It  can  be  corrected  by  making  a  compound 
lens  of  two  kinds  of  glass  having  different  colour  dispersing  powers. 
Such  a  correction  is  necessary  in  many  optical  instruments,  but 
it  is  not  required  for  spectacles  in  which  the  chromatic  aberration 
is  not  noticeable.  Its  presence  in  the  eye,  however,  can  be  easily 
demonstrated. 

§  26.  Cylindrical  Lenses.— A  lead  pencil  is  a  good  example  of 
a  cylinder,  the  lead  running  down  the  centre  being  its  axis.  Any 
lines  on  the  surface,  parallel  to  the  axis,  are  straight  lines,  whereas 
sections  at  right  angles  to  the  axis  are  always  curved.  If  a  slice 
were  taken  off  the  surface  of  the  pencil,  in  the  direction  of  its  length 
or  axis,  and  a  round  piece  cut  out  of  it,  it  would  represent  a  convex 
cylindrical  lens.     A  cast  of  the  surface  of  the  pencil  would  form  a 


408  DISEASES    OF    THE   EYE.  [chap.  xv. 

concave  cylinder.  Cylinders  only  act  in  the  direction  of  their  cur- 
vature— that  is  to  say,  at  right  angles  to  the  axis.  A  cylinder 
has  no  effect  in  tlie  direction  of  its  axis.  Rays  entering  in  the  plane 
of  the  axis  are  not  refracted  (Fig.  144,  a),  and  rays  entering  in  any 
plane  parallel  to  the  axis  (Fig.  144,  h)  are  merely  bent  towards  the 
axis,  but  suffer  no  deviation  in  the  direction  of  the  axis — that  is  to 


Fig.    144. — Refraction  through  a   convex  cylinder.     F,  the 
principal  focus,  is  really  ajine  parallel  to  the  axis. 

say,  vertically  in  Fig.  144.  On  the  other  hand,  rays  in  a  plane  at 
right  angles  to  the  axis,  meeting  the  curved  surface,  are  made  to 
converge  or  diverge,  according  as  the  cylinder  is  convex  or  concave. 
(Horizontal  plane  in  Figs.  144  and  145.)  The  focus  of  a  cylinder 
therefore  is  a  line  parallel  to  the  axis,  and  no  image  is  formed. 

The  position  of  a  cylinder  placed  before  the  eye  is  indicated  by 
the  degree  of  inclination  of  its  axis  to  the  vertical  or  horizontal. 
The  axis  of  the  cylindrical  lenses  used  in  trial-cases  is  shown  by 
two  slight  scratches  at  the  edge,  or  by  two  muffed  portions  parallel 
to  the  axis. 

§  27.  Sphero- Cylindrical  and  Toric  Lenses. — When  it  is  necessary 
to  combine  a  splierical  with  a,  cylindrical  lens,  the  segment  of  the 
sphere  is  usually  ground  on  one  surface  of  the  glass  and  the  cylinder 
on  the  other,  but  in  toric  lenses  the  spherical  and  cylindrical  effect 
is  produced  on  one  surface.  The  nature  of  the  surface  then  re- 
sembles that  of  a  bicycle  tyre,  the  length  of  the  tyre  having  a  flatter 
curve  than  the  breadth. 


CHAP.  XV.]  ELEMENTARY    OPTICS.  409 


§  28.  Numbering  of  Lenses. — The  lenses  in  trial-cases  and  in 
spectacles  are  numbered  according  to  the  metric  system. 

A  lens  of  one  metre  focal  length  is  adopted  as  the  Dioptric  Unit 
or  unit  of  refractive  power,  and  is  called  a  Dioptre  (ID).  The  greater 
the  strength  or  refractive  power  of  a  lens,  the  higher  will  be  its 
number,  and  the  shorter  will  be  its  focal  length  (Fig.  135).     Lenses 


Fig.  145. — Refraction  through  a  concave  cylinder. 

of  2  D  and  4  D  are  twice  and  four  times  as  strong,  respectively, 
as  a  lens  of  1  D,  and  their  focal  length  will  be  inversely,  J  and  J  of 
the  focal  length  of  the  1  D  lens,  that  is  to  say  '^■^  and  ^^,  or  expressed 
in  centimetres  (1  metre  =  100  centimetres),  if^  =  50  cm.,  and  ^J^ 
=  25  cm. 

If,  therefore,  it  be  required  to  ascertain  the  focal  length  of  a 
given  lens,  100  must  be  divided  by  the  dioptric  number  of  the  lens, 
and  the  answer  will  give  the  focal  length  in  centimetres.  For  ex- 
ample, the  focal  length  of  a  lens  of  5  D  is  i"-  =  20  cm. 

If  the  focal  length  of  the  lens  be  known,  and  it  be  desired  to 
ascertain  its  dioptric  number,  we  find  it  by  dividing  100  cm.  by  the 
focal  length.     For  example,   if  the  focal  length  be  33  cm.,  then 

Lenses  of  less  than  1  D  have  of  course  decimal  fractions  for  their 
numbers— e..^.  075,  0-5,  and  0-25.  The  focal  length  of  O'S  D  is  i^ 
=  200  cm.  =  2  metres.  Cylindrical  lenses  are  numbered  in  the  same 
way  as  sphericals.  The  strength  of  two  lenses  in  contact  is  practi- 
cally equal  to  the  sum  of  their  numbers,  if  of  the  same  kind,  and  to 


410 


DISEASES   OF   THE  EYE. 


the  difference  of  their  numbers  if  of  the  opposite  kind — c.(j.  -\ 
lens  combined  witli  —  1  D  lens  equals  a  +  lens  of  3  D. 


[chap,    XV. 

4  1) 


Fig.  140. — Apparent  nioveuieiit, 
in  the  opposite  direction,  pro- 
duced by  displacement  of  a 
convex  lens.  In  position  2, 
O  B  is  deviated  towards  the 
base  of  the  prism  to  D,  and 
OisseenatO'(§  6). 


Fig.  147. — Apparent  movement, 
in  same  direction,  produced 
by  displacement  of  a  concave 
lens.  In  position  2  the 
prism  is  base  up,  O  B  is 
deviated  to  D,  and  O  seems 
to  be  at  O'. 


§  29.  Recognition  of  Spherical  Lenses. — If  a  spherical  lens  be 
moved  before  the  eye,  when  looking  at  an  object  through  it,  the 
object  will  seem  to  move  in  the  opposite  dii'ection  in  the  case  of  a 
convex  lens,  and  in  the  same  direction  if  the  lens  be  concave.  This 
is  due  to  the  prismatic  action  of  the  lenses  (Figs.  146  and  147),  and 
occurs  equally  in  all  diameters. 

§  30.  Recognition  of  Cylindrical  Lenses  and  of  the  Position 
of  the  Axis. — Cylinders  act  in  the  manner  described  above  for  spheri- 
cal lenses,  but  only  in  the  direction  at  right  angles  to  the  axis.  Fur- 
ther, if  a  cylinder  be  rotated  while  an  object  is 
viewed  through  it,  it  produce  a  distortion, 
when  the  axis  is  oblique  with  regard  to  the 
chief  lines  of  the  object.  The  effect  is  best  seen 
if  a  rectangular  object  be  selected,  the  angles  of 
which  are  then  no  longer  right  or  equal.  This 
is  noticeable  even  when  the  cylinder  is  com- 
bined with  a  spherical  lens. 

The  simplest  plan  is  to  look  at  a  vertical 

line  through  the  glass,  and  if  the  axis  of  the 

cylinder  be  either  vertical  or  horizontal,  the  portion  of  the  line 

seen  through  the  glass  appears  to  be  continuous  with  that  outside 

it,    whereas    if   the    axis    be    oblique,    as  in    Fig.  148,  the  portion 


Axis  ^  -. 


CHAP.    XV. 


ELEMENTARY    OPTICS. 


411 


Fig.  149. 


seen  through  the  lens  becomes  twisted  into  the  position  a  h. 
Maddox's  axis-finder,  Fig.  149,  is  based  on  this  principle.  The 
spectacle  frame  is  placed  in  a 
groove  on  the  top  of  the  instru- 
ment, and  is  held  there,  while  both 
are  tilted  round  until  the  line  ap- 
pears continuous  as  at  A,  Fig.  149  ; 
the  pendulum,  P,  then  indicates 
on  the  graduated  arc  the  position 
of  the  axis,  or  the  direction  at 
right  angles  to  it.  The  axis  can 
also  be  found  by  the  lens  measurer. 
*§  31.  To  find  the  Numljer  of 
a  Lens  it  is  only  necessary  to 
neutralise  it  with  a  lens  of  the 
opposite  kind  taken  from  the  trial- 
case.  The  two  lenses  are  held  in 
contact  and  moved  together,  while 

the  apparent  motion  of  an  object  (§  29)  as  seen  through  them  is 
noted,  the  lens  which  stops  all  movement  giving  the  required  number. 
Or  it  can  be  ascertained  more  rapidly  by  the  Geneva  lens  measurer, 
Fig.  150.  The  three  points,  a,  b,  c,  the  central  one,  h,  of  which 
is  movable,  are  applied  to  the  surface  of  the  lens,  and  the  corres- 
ponding number  is  indicated  by  the  pointer  on  the  dial.  Both 
surfaces  of  the  lens  must  of  course  be 
measured.  The  position  of  the  axis  of  a 
cylinder  is  also  easily  found  by  this  instru- 
ment. When  the  points  are  placed  parallel 
to  the  axis  the  index  stands  at  0  (zero), 
showing  that  the  surface  is  plane  in  that 
direction. 

*  §  32.  To  find  the  Optical  Centre  of 
a  Lens  is  often  a  matter  of  practical  im- 
portance. It  can  be  found  in  the  same 
Fig.  150. — Lens  measurer,  way  as  is  the  base-apex  line  of  a  prism 
(Fig.  126).  When  both  the  crossed  lines 
seen  through  the  lens  are  continuous  with  the  portions  outside  the 
lens,  the  optical  centre  is  opposite  the  point  of  intersection  of  the 
ines. 


412 


DISEASES   OF   THE   EYE. 


[chap.   XV. 


Fig.  151. — Prismatic  effect  of 
decentration  of  lenses.  A  B  and 
C  D  represent  the  visual  axes. 


*  §  33.  Decentration  of  Lenses.— Normally,  the  distance  between 
the  optical  centres  of  the  lenses  in  spectacles  should  be  the  same  as 
that  between  the  optic  axes  of  the  eyes  of  the  patient,  otherwise 

a  prismatic  effect  would  be  pro- 
duced. Sometimes,  however,  such 
an  effect  is  desirable,  and  then  it 
can  be  brought  about  by  decentra- 
tion of  the  lenses.  This  may  be 
done  in  one  or  other  of  two  ways, 
namely,  by  altering  the  distance 
between  the  glasses  by  means  of 
the  frames,  or  by  decentring  the 
glass  in  its  rim.  The  effect  of  the 
first  method  is  shown  in  Fig.  151, 
from  which  figure,  too,  it  is  evident 
that,  in  order  to  produce  the  same 
effect,  convex  and  concave  lenses 
must  be  displaced  in  opposite 
directions. 
The  second  method  consists  in  cutting  out  the  lens  so  that  the 
optical  centre  is  displaced  with  reference  to  the  geometrical  centre. 
By  the  geometrical  centre  we  mean  the  central  point  of  the  piece  of 
glass  constituting  the  lens.  In  round  glasses  it  is  of  course  equally 
distant  from  all  parts  of  the  circumference,  and  in  oval  glasses  it 
is  at  the  centre  of  the  horizontal  diameter  of  the  glass.  In  lenses, 
as  commonly  made,  the  optical  centre  coincides  w^ith  the  geometrical 
centre.  Fig.  152  shows  how  a  lens  can  be  cut  so  that  the  optical  centre 
will  be  decentred.  A  B  is  the  lens  as  origin- 
ally ground,  and  B  C  D  is  the  portion  which 
is  cut  out  and  fitted  in  the  spectacle-  rim. 
If  the  whole  of  A  B  were  used,  the  optical 
centre,  0,  would  be  the  geometrical  centre, 
but  in  the  portion  C  B  U  the  point  G,  mid- 
way between  C  D  and  B,  would  be  the 
geometrical  centre,  while  the  optical  centre, 

0,  would  be  decentred.  To  obtain  a  prismatic  effect  of  1"  a  lens 
of  1  D  requires  to  be  decentred  If  cm.  The  stronger  the  lens 
the  greater  is  the  prismatic  effect  produced  by  a  given  amount 
of  decentration,  so  that  a  lens  of  2  1)  need  onlv  be  decentred  half 


A<rw^B 


Fig.  152. — Decentra- 
tion of  a  lens  by  cutting 
out  a  portion  of  it. 


CHAr.   XV.]  ELEMENT ABY    OPTICS.  413 

the  distance  of  a  lens  of  1  1),  in  order  to  produce  the  same  pris- 
matic effect.  Tables  have  been  constructed  giving  the  prismatic 
effect  of  lenses  of  different  strength  corresponding  with  the  extent 
of  the  decentration  in  millimetres.^ 

§  34.  Protective  Glasses. — Glasses  are  chiefly  used  for  the  cor- 
i-ection  of  optical  errors  (lenses),  or  for  the  relief  of  muscular  in- 
sufficiencies (prisms),  but  they  are  sometimes  worn  solely  for  the 
protection  of  the  eyes  from  injury  by  solid  particles  (stone-break- 
ers, mineral-water  operatives,  motorists),  by  heat  (smelters,  glass 
blowers),  by  excessive  light  (snow,  electric  light),  or  as  a  protection 
from  ordinary  daylight  in  acute  inflammation  of  the  eyes  accom- 
panied by  photophobia,  and  during  the  period  immediately  after 
operations  such  as  cataract  extractions.  For  mechanical  protection, 
plate  glass,  celluloid,  or  wire  gauze  spectacles  are  employed.  The 
injurious  effects  of  light,  which  are  most  probably  due  to  the  ultra- 
violet rays,  are  best  prevented  by  a  special  glass,  such  as  amber- 
coloured  glass,  or  a  specially  made  glass  of  a  greenish-yellow  tint 
known  as  '  euphos  '  glass.  For  ordinary  clinical  purposes  smoked 
or  neutral  tint  glasses  are  preferable  to  blue. 

^   See  Maddox's  work  Ophthalmological  Prisms. 


CHAPTER   XVI. 

ABNORMAL   REFRACTION   AND   ACCOMMODATION. 

Ametropia. — It  has  been  explained  (p.  4)  that,  in  Emmetropia 
or  Normal  Refraction,  the  retina  is  at  the  principal  focus  of  the 
dioptric  system.  When  the  retina  does  not  coincide  with  the 
principal  focus,  parallel  rays  no  longer  meet  on  it,  if  the  accommoda- 
tion be  at  rest ;  this  condition  is  called  Ametropia  {a,  priv.  ;  /xirpov, 
standard  ;  wi//),  or  an  error  of  refraction.  There  are  three  varieties 
of  Ametropia.  1.  Myopia  {/jlvuv,  to  close;  oixp),  or  Short-sight; 
in  which  the  principal  focus  lies  in  front  of  the  retina.  2.  Hyper- 
metropia  {vmp,  over  ;  fx^rpov,  standard  ;  wi//),  in  which  the  principal 
focus  lies  behind  the  retina.  3.  Astigmatism  (d,  friv. ;  o-ny/xa,  a 
point),  in  which  the  refraction  of  the  eye  in  its  different  meridians 
is  different.  ^ 

Myopia,  or  8hort-8ight. 

Definition  and  Optical  Causes.— Myopia  is  an  error  of  refraction 
in  which  the  retina  lies  behind  the  principal  focus  of  the  dioptric 
system,  and  in  which  therefore  parallel  rays  of  light  {a  b,  Fig.  153) 
are  brought  to  a  focus,  not  on  the  retina,  but  in  front  of  it  (at  /), 
and  form  on  it  circles  of  diffusion  (c  d). 

Compared  with  emmetropia,  therefore,  the  refraction  of  the 
myopic  eye  is  increased.  This  may  be  due  to  shortening  of  the 
focal  length  by  an  absolute  increase  in  the  refractive  power  of  the 
eye,  brought  about  by  increase  of  the  curvature  of  the  cornea,  as 
in  conical  cornea,  or  of  the  crystalline  lens,  as  in  spasm  of  accommo- 
dation (Curvature  M.),  or  by  alteration  in  the  refractive  index  of 
the  crystalline  lens  (Index  M.),  as  in  some  cases  of  commencing 
cataract,  or  by  forward  displacement  of  the  lens,  but  in  all  of  these 
the  myopia  is  of  secondary  importance. 

414 


CHAP,  xvr.j 


MYOPIA. 


41. 


The  most  conunon  cause  of  myopia,  is  an  elongation  oi  the 
antero-posterior  axis  of  the  eyeball  (Axial  M.),  and  in  this  case  the 
increase  of  the  refraction  is  therefore  onlv  relative. 


Fig.   153. 

Far  Point  (Punctum  Remotum,  R.)  of  the  Myopic  Eye.— The 
myopic  eye  cannot  see  distant  objects  (at  six  metres  or  more)  dis- 
tinctly, because  of  the  circles  of  diffusion  (c  d,  Fig.  153),  but  if  the 
object  be  brought  closer,  its  conjugate  focus  (§  16,  chap,  xv.)  will 
lie  farther  back  than  /,  Fig.  153,  and  when  the  object  reaches  a  certain 
point  nearer  to  the  eye,  say  R.  Fig.  15-1,  its  conjugate  focus  will  meet 
the  retina  (at  c)  and  it  will  be  distinctly  seen.  This  point — which 
is  the  farthest  point  of  distinct  vision — is  the  Far  Point  or  Punctum 
Remotum  (R.)  The  myopic  eye  is  therefore  adapted  for  seeing 
near  objects.  Conversely  rays  emerging  from  c  will  unite  at  R, 
which  is  the  conjugate  focus  of  the  retina.     It  will  be  observed  that, 


Fig.   154, — Far  point  of^a^myopic  eye. 


in  myopia,  R  is  real  and  can  actually  be  measured,  that  it  lies  in 
front  of  the  eye  and  is  a  positive  quantity.  As  the  position  of  R 
in  front  of  the  eve  determines  the  nature  of  the  error  of  refraction, 


410 


DISEASES    OF    THE   EYE. 


[chap.    XVI. 


so  the  degree  of  error  depends  on  the  distance  of  R  from  the  eye  ; 
the  longer  the  eyeball  the  closer  is  R,  and  the  greater  is  the  error  of 
refraction.     In  other  words,  the  error  of  refraction  (;•)  is  the  inverse 

of  the  distance  of  the  Far  Point  (R),  r  =  — ,  and  conversely  of  course 

R 


R 


These  are  .general  equations  for  all  errors  of  refi'action. 


Optical  Correction  of  Myopia. — The  optical  correction  of  an  error 
of  refraction  is  accomplished  by  placing  in  front  of  the  eye  a  lens 
which  renders  it  emmetropic,  or  enables  it  to  bring  parallel  rays 


Fig. 


-Correction  of  myopia. 


[a,  h,  Fig.  155)  to  a  focus  on  the  retina,  without  any  eSort  of  accom- 
modation, and  thus  renders  the  vision  of  distant  objects  distinct. 
Since  rays  diverging  from  the  punctum  remotum  (R,  Fig.  155)  are 
brought  to  a  focus  on  the  retina  in  the  myopic  eye,  the  correcting 
lens,  L,  must  evidently  give  to  parallel  rays  such  a  degree  of  diver- 
gence before  they  pass  into  the  eye,  as  though  they  came  from  this 
punctum  remotum.  This  lens  must  therefore  be  a  concave  or 
diverging  lens,  and  its  principal  focus  must  be  at  R  ;  that  is  to  say, 
the  focal  length  of  the  lens  must  be  equal  to  the  distance  of  the  far 
point  from  the  eye,  in  this  case  14  cm.  The  focus  of  the  glass  and 
the  punctum  remotum  of  the  eye  are  then  identical ;  and  therefore, 
parallel  rays,  after  passing  through  the  glass,  will  have  a  divergence, 
as  though  they  came  from  the  punctum  remotum,  and  will  form 
an  exact  image  of  the  distant  object  on  the  retina.  It  is  evident 
that  the  glass  will  also  make  the  rays  emerging  from  the  eye  parallel. 
The  number  of  the  glass,  in  this  case,— 7  D  (=  -^{-),  will  indicate 
the  degree  of  the  myopia — i.e.  by  how  many  dioptres  the  refracting 
power  of  the  eye  is  in  excess  of  that  of  an  emmetropic  eye.     The 


ciiAr.  xvj,] 


MYOPIA. 


417 


longer  the  eyeball  the  shorter  is  the  distance  of  the  far  point  from 
it ;  and  therefore  the  shorter  must  be  the  focal  length  of  the  cor- 
recting lens,  and  the  higher  must  be  its  number.  The  degree  of 
myopia  therefore  increases  with  the  elongation  of  the  eyeball. 

In  the  explanation  of  the  correction  of  myopia  given  above,  the 
correcting  glass  was  assumed  to  be  in  contact  with  the  cornea.  In 
practice,  however,  the  glass  is  placed  a  short  distance  in  front  of  the 
cornea,  and  consequently,  must  be  stronger  than  the  theoretical  cor- 
rection. For  example  :  if  the  punctum  remotum  (Fig.  156)  be 
situated  at  20  cm.  from  the  eye,  then  the  number  of  the  correcting 
lens  in  contact  with  the  eye,  and  the  real  measure  of  the  myopia, 
will  be  —  5  D,  because  the  focal  distance  of  this  lens  is  20  cm.  {h^^- 
=  5).  But  if,  in  the  above  case,  the  distance  from  cornea  to  glass 
be  2  cm.,  the  required  lens  in  practice  will  be  —  5*5  D  (Y^/  =  5*5), 


Fia.    15G. — Effect  of  the  po-iition  of  the  lens  in  the  correction 
of  myopia. 

Evidently,  the  farther  the  lens  is  from  the  eye  the  stronger  must  it 
be  ;  and  it  is  therefore  advisable  that  correcting  lenses  should  be 
worn  at  the  same  distance  from  the  eye  as  are  the  trial- lenses  when 
used  to  estimate  the  degree  of  ametropia.  In  the  example  just 
given  the  difference  between  the  theoretical  and  practical  amount  of 
myopia  is  very  slight,  but  it  becomes  greater  the  higher  the  myopia. 
In  a  theoretical  M.  of  20  D,  the  lens  required  if  placed  at  2  cm.  from 
the  eye  would  be  —  33  D. 

Diagnosis  and  Determination  of  the  Degree  of  Myopia.— The 
degree,  or  amount,  of  myopia  may  be  determined  either  objectively 
by  the  ophthalmoscope,  or  subjectively  by  means  of  the  trial-lenses 
and  test-types. 

Subjective  Method. — Examining  each  eye  separately,  we  find 
the  correcting  glass  by  placing  our  patient  as  directed  in  the  section 
27 


418  DISEASES   OF    THE   EYE.  [chap.  xvi. 

on  AcutcMcss  uf  \'isioii  (p,  14).  Having  first  tested  V.  without  a 
glass,  a  weak  concave  trial-glass  is  then  placed  before  the  eye  under 
examination,  and  liigher  numbers  are  gradually  proceeded  to,  until 
that  glass  is  reached  which  gives  the  eye  the  best  distinguishing 
power  for  the  types.  In  order  to  save  time,  the  distance  of  the 
far  point  can  be  found  approximately  with  small  print,  and  the  degree 
of  M.  deduced.  A  lens  a  little  lower  than  this  may  be  taken  to 
commence  with.  We  often  find  that  there  are  several  glasses, 
with  each  of  which  the  patient  can  see  equally  well.  The  weakest 
of  these  is  the  measure  of  his  myopia.  When  a  higher  glass  than  this 
is  used  the  patient  may  still  see  well,  but  he  does  so  only  by  an  effort 
of  accommodation  {i.e.  the  crystalline  lens  has  to  be  made  more 
convex,  in  order  to  compensate  for  the  excessive  concavity  of  the 
glass  placed  in  front  of  the  eye),  and  the  glass  employed  represents 
then,  not  merely  the  myopia  present,  but  also  this  accommodative 
effort.  It  is  therefore  a  serious  mistake  to  prescribe  too  strong  con- 
cave glasses  for  a  myopic  individual. 

The  Ophthalmoscopic  Methods  wnll  be  explained  in  detail 
farther  on  (p.  447),  and  need  only  to  be  mentioned  here. 

Direct  method  at  a  distance. — The  retinal  vessels  are  visible  and 
appear  to  move  in  the  opposite  direction  to  the  motion  of  the  ob- 
server's head. 

Indirect  method. — The  optic  disc  appears  to  increase  in  size  when 
the  object  lens  is  drawn  away  from  the  patient's  eye. 

Direct  method. — The  fundus  and  vessels  are  indistinct,  and  the 
lowest  concave  glass  which  makes  them  distinct  is  the  measure  of 
the  myopia. 

Rhinoscopy . — With  a  plane  mirror  the  shadow  moves  against 
the  direction  in  which  the  mirror  is  rotated,  provided  the  observer 
is  farther  from  the  patient's  eye  than  the  far  point  of  the 
latter. 

The  Amplitude  of  Accommodation  in  Myopia. — The  myopic  eye  has 
an  excess  of  refractive  power  (r)  as  compared  with  the  emmetropic  eye  ; 
therefore,  in  calculating  its  amplitude  of  accommodation,  tliis  excess 
must  be  subtracted  from  the  positive  refractive  power  (p),  which  would 
be  required  to  adapt  the  emmetropic  eye  to  the  same  punctum  proxi- 
mum  ;  or,  in  other  words,  the  myopic  eye  has  need  of  less  accommoda- 
tive power  than  the  emmetropic  eye,  because,  even  at  rest,  it  is  adapted 
for  a  distance  (R.,  its  iDunctum  remotum)  for  which  the  emmetropic  eye 
has  to  accommodate  ;    hence  in  myopia 

a  =  p  —  r. 


CHAP.    XVI.] 


MYOPIA. 


410 


For  exainplo  :    a  myopo  of  4  D  who  cuii  iiccoiiiinodalo  up  to  1 1  cm. 
{p   =  W    =  -J  ^)  1^'^^  '^'^  iunplitiido  of  accoininodation  of  9  —  4  =  5  D. 
Range  of  Accommodation  in  Myopia. — In  myopia  both  R.  and  P.,  and 

therefore  the  range  of  accommodation,  are  brought  closer  to  the  eye.     The 


-8/> 


12  b  cm 


p'-ik-'" 


8J) 


H=^33  cm 


3D 


9  cm 


8  +  3=///> 


20  cm. 


Fig.  157. — Range  of  accommodation  in  emmetropia  (E.),  in  myopia 
(M.)  and  hypermetropia  (H.)  of  3  D  each,  the  amplitude  of  accommoda- 
tion in  all  cases  being  8  D, 

range  is  also  shortened  as  can  be  seen  from  Fig.  157,  which  shows  the  range 
of  Ace.  withan  amplitudeof  8  D,in Em., andin M.  and  H.  of  3  D, respectively. 
In  this  case,  R  is  known  from  the  refraction  (R  =  ^  ~  \  =33  cm.)  ; 
it  remains  therefore  only  to  determine  P.  We  saw  above  that  in  M.  a  = 
p  —  r,  therefore  p  =  a  +  r  =8  +  3   =11  D,  and  P.    =  -  =  iV   =  9  cm. 

The  Angle  y  in  Myopia. — In  myopia,  owing  to  the  length  of  the  eye- 
ball, the  cornea  is  cut  closer  to  its  centre  by  the  visual  line  (M.  Vi  .,  Fig.  1 58) 
than  in  emmetropia  ;j  or,    by    displacement   of   the   macular  region  the 


Fig.    158. — Angle   y   in   emmetropia    (Em.),    myopia    (M.),    and 
hypermetropia  (H.), 

visual  line  and  the  optic  axis  (A  O)  may  coincide  ;  or,  the  cornea  may 
even  be  cut  to  the  outside  of  its  centre  by  the  visual  line.  In  any  of 
these  cases,  but  especially  in  the  latter,  the  effect  will  be  that  of  an  apparent 
convergent  strabismus. 


420  DISEASES   OF   THE  EYE.  [chap.  xvi. 


Etiology. —Myopia  is  rarely  congenital.  Infants  are  hyper- 
metropic, but  as  they  grow  older  the  eye  tends  to  become  less  hyper- 
metropic, or  emmetropic,  or  even  in  some  cases  myopic.  Myopia 
is  almost  wliolly  a  result  of  civilisation,  and  its  development  and 
progressive  increase  are  due  to  the  use  of  the  eyes  for  near  work, 
such  as  reading,  sewing,  drawing,  etc.,  which  causes  elongation  of 
the  antero-posterior  axis  of  the  eye.  Only  the  portion  of  the  eye- 
ball posterior  to  the  insertion  of  the  orbital  muscles  takes  part  in 
the  change  of  shape.  It  is  more  common  in  cities  than  in  the  country, 
and  occurs  especially  in  the  higher  schools,  among  the  professional 
classes,  and  those  occupied  with  fine  work.  Opinions  are  divided 
as  to  the  way  in  which  close  work  causes  myopia.  The  effort  of 
accommodation  is  not  the  cause,  but  rather  the  pressure  exercised 
on  the  eyeball  by  the  recti  or  superior  oblique  muscles  during  con- 
vergence. Heredity  also  plays  a  part,  the  nature  of  which  is  not 
clear ;  but  it  would  seem  probable  that  some  anatomical  or  con- 
stitutional predisposition  is  transmitted  from  parent  to  offspring. 
Finally,  the  higher  degrees  of  myopia  are  very  constantly  complicated 
with  pathological  changes  at  the  posterior  pole  of  the  eye,  called  by 
some  posterior  sclero-chorioiditis,  and  regarded  by  them  as  in- 
flammatory, while  others  attribute  them  to  the  mechanical  distension 
of  the  coats  of  the  eye,  consequent  on  its  elongation.  How  far  this 
disease  is  either  the  consequence,  or  the  cause,  of  the  elongation  of 
the  globe  has  yet  to  be  decided. 

It  should  also  be  stated  that  anything  which  encourages  ap- 
proximation of  objects  to  the  eye  such  as  defective  print,  bad  light, 
or  indistinctness  of  vision,  e.g.  astigmatism,  and  nebula?  of  the  cornea, 
may  act  as  indirect  causes.  The  development  of  myopia  may  also 
be  assisted  by  anything  which  tends  to  produce  congestion  of  the 
head  and  eyes,  such  as  stooping  over  books,  as  a  result,  for  instance, 
of  badly  constructed  school  desks.  In  rare  instances,  myopia  has 
been  observed  to  develop  or  increase  considerably  after  a  severe 
illness.  That  it  is  not  always  due  to  close  work,  is  shown  by  the  facts 
that  high  degrees  of  myopia  are  veiy  occasionally  met  with  in  young 
children  before  they  have  begun  to  use  their  eyes  much  for  near 
objects  ;  and  that  the  worst  cases  may  sometimes  be  met  with  in 
agricultural  labourers,  who  have  done  little  or  no  close  work. 

Myopia,  as  a  rule,  first  shows  itself  from  the  eighth  to  the  fifteenth 
year,  and  is  apt  to  increase,  especially  during  the  early  years  of 


CHAP.  XVI.]  MYOPIA.  421 


puberty.  After  this  the  majority  of  cases  remain  stationary,  but 
others  continue  to  increase  during  the  whole  lifetime,  either  periodi- 
cally or  continuously,  and  may  reach  30  D  or  more. 

Simple,  or  Non-Progressive  Myopia.— In  this  variety,  the  M. 
ceases  to  increase  when  the  body  has  reached  its  full  development, 
and  does  not,  as  a  rule,  go  beyond  three  or  four  dioptres.  The  eye 
is  perfectly  sound  and  presents  no  disease  of  the  fundus,  except 
occasionally  a  slight  crescent  at  the  outer  side  of  the  optic  disc 
(Plate  IX.  Fig.  1).  This  form  of  myopia  is  sometimes  regarded  as  a 
harmless  adaptation  of  the  eye  to  the  requirement  of  civilisation, 
and  as  being  different  in  its  etiology  from  the  progressive  form, 
which  is  a  true  disease.  Unfortunately  it  is  not  possible  to  dis- 
tinguish with  certainty  one  form  from  the  other  in  the  earliest 
stage.  But  if  a  patient  of  sixteen  years  of  age  or  more  have  a 
low  degree  of  M.,  say  only  of  2  D  or  3  D,  and  especially  if  there 
be  no  crescent,  one  may  feel  fairly  confident  that  the  M.  will  become 
stationary  when  the  patient  is  fully  grown.  The  points  which 
guide  one  in  the  prognosis  are  the  age  of  the  patient  compared  with 
the  amount  of  the  M.,  and  the  appearance  of  the  fundus. 

Spasmodic  Myopia — that  is  to  say,  M.  due  to  spasm  of  accom- 
modation— is  a  condition  which  is  not  uncommon,  and  one  which 
is  frequently  seen,  during  the  transition  of  H.  or  Em.  into  M.  The 
M.  disappears  under  atropine,  only  to  return  when  the  use  of  the 
latter  is  discontinued. 

Symptoms  of  Myopia.— The  symptoms  of  M.,  apart  from  the 
complications  which  occur  in  the  high  degrees,  and  which  will  be 
considered  later  on,  are  dependent  on  the  optical  error  of  the  eye, 
and  are  very  few.  Distant  vision  is  impaired  according  to  the 
degree  of  M.  present,  but  many  short-sighted  people  half  close  their 
eyes  in  order  to  diminish  the  size  of  the  diffusion  circles  on  the  retina, 
and  they  are  thus  enabled  to  see  a  little  better.  It  is  this  habit 
which  has  given  rise  to  the  term  myopia  (p.  414).  The  smallest  print 
can  be  distinguished  with  great  facility,  at  or  within  the  near  point ; 
and  as  the  retinal  images  are  larger  than  in  emmetropia  and  con- 
sequently require  less  illumination  for  their  perception,  short-sighted 
persons  are  much  given  to  reading  in  bad  light.  If  the  patient 
reads  at  his  far  point  no  accommodation  is  necessary,  and  for  a 
nearer  point  the  accommodation  being  less  than  in  emmetropia, 
one  of  the  stimuli  to  convergence  is  deficient,  and  in  some  cases  this 


422 


DISEASES   OF   THE   EYE. 


[chap.    XVI. 


leads  to  latent,  or  even  to  absolute  divergence  (see  Insufficiency  of 
Convergence,  chap.  xvii.). 

The  particles  which  normally  float  in  the  vitreous  humour  are 
rendered  more  noticeable  by  the  larger  shadows  which  they  cast 
on  the  retina  ;  and  this  is  one  of  the  reasons  why  myopic  people 
are  so  frequently  troubled  by  black  spots  (muscat  volitantes)  before 
their  eyes.  That  short  sight  improves  with  age,  or  is  the  strongest 
kind  of  eye,  is  a  fallacy  which  owes  its  origin  to  the  absence  or  de- 
layed onset  of  presbyopia  in  myopic  people  ;  and  also  to  the  fact 
that,  in  low  degrees  of  myopia,  the  vision  may  improve  a  little  at 
a  distance  owing  to  the  small  size  of  the 
pupils  in  old  people,  or  to  the  slight  di- 
minution in  the  refractive  power  of  the 
lens  which  occurs  at  about  sixty  years  of 
age  (cf.  Presbyopia). 

Progressive  Myopia  frequently  becomes 
complicated  with  Organic  Disease,  and  to 
the  more  serious 
Myopia  may  be 
are  the  forms 
with  : 

1.  Posterior   Staphyloma,   or   Myopic  Cres- 
cent. — This    condition    is    recognised    by    the 
ophthalmoscope  as   a  more  or   less   extensive 
white    crescent    at    the    outer    circle    of    the 
optic  papilla. 
Fig.  159  explains  the  manner  in  which  it  arises.     The  bulging 
of  the  eyeball,  at  X,  takes  place  at  the  posterior  pole,  in  the  direction 
of  the  axis  A  X.     The  chorioid  c  becomes  drawn  towards  the  tem- 
poral side,  and  the  optic  nerve  appears  to  be  displaced  in  the  opposite 
direction.     The  chorioid  is,  consequently,  drawn  over  the  edge  of 
the  scleral  opening  at  the  nasal  side  at  n,  while  it  becomes  detached 
and  drawn  away  from  it  at  the  outer  side  at  t,  the  portion  of  sclerotic 
thus  exposed  appearing  as  a  white  crescent  at  the  temporal  edge  of 
the  disc  (Plate  IX.   Fig.    1).     As  the  bulging  increases,   with  in- 
crease of  the  myopia,  it  extends  to  the  nasal  side  of  the  nerve  as 
well,    the   chorioid   also   becoming   atrophied ;     and   the   posterior 
staphyloma  ^  is  then  seen  with  the  ophthalmoscope  completely  sur- 
'    Staphyloma  \n  ophthalmology  m.eans  a  bulging  of  the  coats  of  the 


cases   the   term   Pernicious 

applied.      The     following 

of     organic     disease     met 


Fig.  159. — Explains 
formation  of  myopic 
crescent. 


.a  s-8 


.oi'5 


PLATE    IX. 

{To  face  page  422.) 

Fia.  1. — This  represents  a  small  myopic  crescent  in  a  case  of  myopia  of 
3*5  D.  The  orescent  is  white,  and  is  situated  on  the  temporal  side 
of  the  disc. 

Fig.  2. — Posterior  staphyloma  in  myopia  of  high  degree.  The  staphy- 
loma surrounds  the  disc,  but  the  larger  portion  of  it  is  on  the  tem- 
poral side.  The  disc  appears  as  a  vertical  oval.  The  chorioidal 
vessels  have  become  visible  in  the  neighbourhood  of  the  disc,  owing 
to  atrophy  of  the  pigment-epithelium.  The  macular  region  (to  the 
left)  shows  evidences  of  disease,  in  the  form  of  atrophic  spots  and 
lines,  irregular  pigmentation,  and  haemorrhages. 


Plate  IX. 


l..\v. 


Fig.   1.     Myopic  Crescent. 


l..\V, 

Fig.  2.      Large  Posterior  Staphyloma. 


CHAP.   XVI.]  MYOPIA.  423 

rounding  the  disc,  but  always  larger  at  the  temporal  side.  The 
stretching  of  the  retina  may,  in  extreme  cases,  derange  its  functions 
and  increase  the  size  of  the  blind  spot.  The  disc  itself  appears  oval, 
owing  to  the  oblique  position  which  the  nerve  head  acquires  (Plate 
IX.  Fig.  2).  The  size  of  the  staphyloma  generally  corresponds  with 
the  degree  of  M.  although  exceptions  to  this  occur.  Every  case 
in  which  a  small  crescent  is  present  is  not  to  be  regarded  as  serious  ; 
for  much  here  depends  on  the  age  of  the  patient  and  the  degree  of 
the  myopia.  The  younger  the  patient  and  the  higher  the  myopia, 
the  more  serious  is  the  outlook. 

2.  Chorioidal  Degeneration  in  the  Neighbourhood  of  the  Macula 
Lutea  (Plate  IX.  Fig.  2). — This  should  always  be  carefully  looked  for, 
as  the  region  of  the  yellow  spot  is  very  liable  to  disease  in  the  worst 
cases  of  progressive  myopia.  The  disease  seems  to  begin  in  the 
chorioid,  giving  the  appearance  of  small  cracks  or  fissures,  which, 
at  a  later  period,  develop  into  a  patch  of  chorioidal  atrophy.  The 
retina  at  the  yellow  spot  becomes  gradually  disorganised,  and  very 
serious  disturbance  of  vision,  associated  in  the  early  stages  with 
metamorphopsia,  is  the  result,  the  patient  being  disabled  from 
reading,  although,  as  the  periphery  of  the  fundus  is  usually  sound, 
he  can  find  his  way  about  freely.  Treatment  can  do  little  here. 
Abstention  from  near  work,  and  the  wearing  of  dark  glasses,  are  to 
be  recommended. 

3.  Chorioidal  Exudation  in  the  Neighbourhood  of  the  Macula 
Lutea. — A  small  grey  spot  of  exudation  may  appear  in  the  chorioid 
at  this  place,  accompanied  by  loss  of  sight  for  reading.  These  cases 
are  often  amenable  to  active  mercurial  treatment,  when  sight  may 
be  restored.  Should  the  case  be  neglected  or  run  a  bad  course, 
vision  will  be  permanently  damaged  from  secondary  chorioidal  de- 
generation. 

4.  The  Black  Spot  in  Myopia. — This  disease  also  attacks  the 
chorioid  in  the  region  of  the  yellow  spot,  and  causes  a  loss  of  central 
vision,  as  in  the  two  previous  forms  of  disease.  The  appearance 
shown  by  the  ophthalmoscope  is  that  of  a  black  spot,  usually  quite 


eye  (see  anterior  staphyloma,  pp.  146  and  171).  In  myopia  the  area  of 
atrophy,  called  above  posterior  staphyloma,  is  smaller  than  the  real  area 
of  distension  of  the  back  of  the  eye.  This  is  apparent  in  Fig.  159.  The 
edge  of  this  true  posterior  staphyloma  can  sometiines  be  seen  with  the 
ophthalmoscope,  the  retinal  vessels  suddenly  dipping  in  over  it. 


424  DISEASES   OF    THE   EYE.  [chap.  xvi. 

circular  and  with  a  defined  margin.  In  the  early  stages  its  size  is 
much  smaller  than  that  of  the  papilla,  but  later  it  often  attains  a 
dimension  of  two  papilla  diameters,  or  more.  The  spot  is  rarely 
of  an  equal  intensity  of  blackness  all  over,  but  towards  its  centre  a 
faint  reddish  liue  often  shines  through  in  places.  At  a  later  stage 
the  black  spot  becomes  surrounded  by  a  narrow  whitish  l)order, 
while  towards  its  centre  it  becomes  less  black,  and  finally  greyish 
or  even  white,  its  margin  remaining  black.  Although  small  haemor- 
rhages, which  often  occur  in  the  neighbourhood  of  the  black  spot, 
gave  rise  to  the  opinion  that  the  black  spot  was  itself  the  result  of 
hsemorrhage,  yet  this  seems  not  to  be  so,  as  the  investigations  of 
E.  Lehmus  have  shown.  The  disease  consists  in  a  proliferation  of 
the  pigment  epithelium,  combined  with  a  gelatinous  exudation, 
which  in  the  case  examined  had  attained  a  thickness,  at  the  centre 
of  the  black  spot,  of  two-thirds  that  of  the  chorioid.  The  chorioid 
was  but  very  slightly  altered,  and  the  glass  membrane  was  quite 
normal.  At  the  margin  of  the  proliferating  region  the  pigment 
epithelium  was  found  to  be  paler  or  even  quite  free  from  pigment. 
The  black  spot  very  gradually,  in  the  course  of  years,  attains  its 
ultimate  dimensions,  and  then  very  slowly  retrogresses,  until  finally 
its  place  is  taken  by  a  greyish  or  bluish-white  scar.  Treatment  is 
of  no  avail,  and  central  vision  does  not  become  restored. 

5.  General  Chorioidal  Atrophy. — In  advanced  cases  of  pernicious 
myopia,  large  patches  of  chorioidal  atrophy,  other  than  the  crescent, 
are  often  present,  chiefly  in  the  region  of  the  posterior  pole,  but  often 
also  towards  the  periphery  of  the  fundus.  The  vitreous  humour  in 
these  cases  is  more  fluid  than  normal,  and  usually  contains  many 
opacities.  Treatment  by  means  of  sub-conjunctival  saline  injections 
is  occasionally  of  use  in  clearing  up  the  vitreous  humour,  and  thus 
effects  some  improvement  of  vision.  The  eyes  should  not  be  used 
for  near  work,  and  dark  glasses  should  be  worn. 

6.  Hcemorrhage  in  the  Retina  at  the  Yelloiv  Spot  may  occur,  and 
when  the  hjicmorrhage  becomes  absorbed  the  macula  lutea  may  not 
recover  its  function,  owing  to  the  delicate  retinal  tissue  having  been 
seriously  damaged.  Yet  we  often  meet  with  cases  of  this  kind  which 
do  regain  their  former  vision.  Rest  of  the  eyes  and  dark  glasses 
should  be  prescribed. 

7.  Detachment  of  the  Retina. — This  is  a  frequent  and  most  serious 
complication  of  progressive  myopia,  and  sometimes  leads  to  second- 


CHAP.  XVI.]  MYOPIA.  425 

ary  cataract  and  even  to  shrinking  of  the  eyeball  (Phthisis  Bulbi). 
It  has  been  considered  in  the  chapter  on  Diseases  of  the  Retina. 

In  high  degrees  of  M.  the  eyes  are  unduly  prominent,  and  the 
sclerotic  appears  flatter  at  the  sides  ;  the  pupils  are  usually  large 
and  the  anterior  chamber  deep,  owing  to  the  slight  development  of 
the  ciliary  muscle  in  consequence  of  the  non-use  of  accommodation. 

Functional  Anomalies  attending  Progressive  Myopia. — 

{a)  Insufjicicncij  of  Convergence  is  almost  always  associated  with 
progressive  myopia,  and  is  the  re.iult  of  two  causes,  namely  the 
diminished  impulse  to  convergence  produced  by  the  absence  of 
accommodation,  and  the  mechanical  difficulty  introduced  by  the 
elongation  of  the  eyes.  The  insufficiency  of  convergence  may  be 
only  latent,  or  it  may  lead  passively  to  absolute  divergent  strabismus 
(chap.  xvii.). 

(6)  Cramp  of  Accommodation  is  often  present  and  causes  an 
apparent  increase  in  the  myopia  (p.  421). 

The  Management  of  Myopia.— In  view  of  the  tendency  to  in- 
crease, to  which,  especially  during  adolescence,  nearly  every  case  of 
short-sight  is  liable,  and  of  the  fact  that  in  a  given  case  we  cannot 
tell  to  what  extent  this  increase  may  go,  and,  finally,  as  the  high 
degrees  almost  invariably  lead  to  disease  of  the  eye,  the  manage- 
ment of  myopia,  including  the  prescribing  of  glasses  for  it,  is  one 
of  the  most  important  matters  with  which  we  have  to  deal. 

The  Prescribing  of  Glasses  in  Myopia. — It  is  not  necessary  to 
prescribe  glasses  for  very  slight  degrees  of  myopia  (up  to  TO  D  or 
rS  D)  ;  yet,  should  the  patient  desire  to  wear  correcting  glasses 
for  distant  objects,  there  can  be  no  objection  to  it.  But  for  cases  of 
myopia  of  2*0  D  or  more,  unless  presbyopia  be  also  present,  it  be- 
comes very  desirable  to  prescribe  glasses  which  fully  correct  the 
myopia,  to  be  worn  constantly — i.e.  for  both  distant  and  near 
objects  ;  and,  should  the  myopia  increase,  to  accordingly  increase 
from  time  to  time  the  strength  of  the  glasses. 

We  now  know%  on  the  one  hand,  that  the  action  of  the  muscle 
of  accommodation  does  not  produce  a  pull  on  the  chorioid  farther 
back  than  the  equator  of  the  eyeball,  while  on  the  other  hand  it  is 
at  the  posterior  pole  that  the  diseased  processes  in  myopia  com- 
mence. Nor  does  the  ciliary  muscle  by  raising  the  tension  of  the 
eye,  nor  in  any  other  way,  cause  an  elongation  of  the  eyeball.  Hence, 
there  is  no  reason  to  spare  the  healthy  myopic  eye  any  ordinary 


426  DISEASES   OF    THE   EYE.  [chap.  xvr. 


effort  of  accommodation.  Indeed,  it  is  reasonable  to  think  that  if 
normal  efforts  be  required  of  the  ciliary  muscle,  its  more  healthy 
tone  will  improve  the  general  healthy  nutrition  of  the  uveal  tract,  and 
consequently  will  tend  rather  to  avert  morbid  changes  in  it. 

On  the  other  hand,  the  diminution  of  the  angle  of  convergence 
at  near  work  is  a  truly  important  matter,  for  the  reason  above 
stated  ;  but  it  is  more  effectually  provided  for  by  full  than  by  partial 
correction. 

Practical  experience  is  here  even  more  valuable  than  theory, 
and  it  shows  that  in  a  large  majority  of  those  patients  whose  short-, 
sight  has  been  fully  corrected  in  youth,  and  who  have  worn  their 
spectacles  constantly  for  a  number  of  years,  the  myopia  in  many 
instances  has  not  increased  at  all,  while  in  a  large  proportion  the 
increase  will  have  been  moderate,  and  in  but  a  small  proportion 
marked  pernicious  progress  will  be  noted.  In  short,  the  tendency 
to  increase  of  the  myopia,  and  to  organic  disease,  is  less  than  in  those 
myopes  who  have  either  worn  no  glasses,  or  but  partially  correcting 
glasses. 

Well-fitting,  properly  centred  spectacles  are  much  to  be  preferred 
to  folders,  which  are  difficult  to  keep  correctly  centred  before 
the  eyes.  Any  astigmatism  present  should  always  be  corrected. 
Patients  whose  eyes  are  healthy,  and  who  wear  constant  full  correc- 
tion, may  be  permitted,  and  even  encouraged,  to  use  their  eyes 
freely  for  near  work,  always  keeping  the  work  as  far  from  the  eyes 
as  possible,  to  diminish  the  angle  of  convergence.  With  this  latter 
object  in  view,  too,  well-printed  books,  ample  light,  and  suitable 
reading-  and  writing-desks  should  be  provided  in  all  educational 
establishments,  and  for  home  studies. 

But  in  prescribing  the  full  correction  for  constant  wear  to  young 
short-sighted  persons,  we  meet  with  some  difficulties.  The  first  of 
these  is  due  to  the  range  of  accommodation,  which  is  imperfect  in 
the  myopic  eye,  and  consequently  the  patients  may  complain  of 
painful  accommodative  sensations  when  first  using  their  fully 
correcting  lenses  for  near  work,  and  sometimes  they  decline  to  persist 
in  the  attempt.  These  complaints  are  more  likely  to  be  made  by 
patients  of  about  twenty  years  of  age  or  more,  whose  habit  of  use  of 
their  eyes  (relative  amplitude  of  accommodation,  and  degree  of 
convergence)  has  become  more  or  less  confirmed,  and  in  whom  the 
power  of  accommodation  has  naturally  diminished  to  an  appreciable 


CHAP.  XVI.]  MYOPIA.  427 

degree.  Patients  should  be  encouraged,  in  spite  of  discomfort,  to 
continue  for  some  time  longer  to  read,  etc.,  with  the  full  correction, 
when,  very  often,  the  relative  amplitude  of  accommodation  will 
gradually  improve,  and  the  discomfort  will  cease.  Or,  a  lower 
number  than  the  full  correction  may  be  ordered,  and  the  strength 
gradually  increased,  until  in  the  course  of  some  weeks  or  more, 
the  full  correction  can  be  worn  for  near  work  with  ease. 

Myopic  persons  of  middle  age  and  over,  who  have  never  worn 
the  full  correction,  will  rarely  tolerate  it. 

Operative  Cure  of  Myopia. — This  consists  in  diminishing  the  refrac- 
tion of  the  eye  by  the  removal  of  the  crystalHne  lens.  Some  surgeons 
simply  extract  the  clear  lens,  while  the  majority  now,  including  the  authors, 
perform  discission,  followed,  in  a  few  days,  by  the  evacuation  of  the  swollen 
and  cataractous  lens,  and  in  some  cases  by  a  subsequent  capsulotomy. 
A  larger  number  of  operations  than  this  is  apt  to  be  injurious  ;  moreover, 
the  swollen  lens  should  be  removed  before  the  tension  of  the  eye  becomes 
increased.  For  both  of  these  reasons,  therefore,  simple  discission  without 
extraction  is  inferior  to  the  other  method.  There  are  grounds  for  sus- 
pecting that,  in  these  highly  myopic  eyes,  the  tendency  to  retinal  detach- 
ment is  increased  by  the  operation,  although  this  has  not  been  shown  by 
statistics. 

The  operative  cure  of  myopia  is  not  to  be  recommended  except  for 
cases  of  1 5  D  and  more  ;  nor  should  it  be  performed  where  there  is  such 
serious  disease  of  the  fundus  or  vitreous  humour  as  would  render  any  im- 
proved use  of  the  eye  on  conclusion  of  the  treatment  unlikely.  Active 
chorioidal  disease  is  regarded  as  a  contra-indication,  but  small  retinal 
haemorrhages,  even  if  they  be  near  the  macula  lutea,  need  not  be  so  re- 
garded. The  best  time  of  life  for  the  cure  is  in  childhood  or  in  early  youth, 
but  it  can  be  successfully  undertaken  at  a  much  later  period.  In  the 
myopic  eye  the  nucleus  of  the  lens  undergoes  sclerosis  to  a  less  extent 
than  in  hypermetropia  or  in  emmetropia,  and  hence  in  it  discission  is  less 
apt  to  be  followed  by  high  tension  or  other  complication,  even  when 
performed  in  middle  age. 

The  advantages  gained  by  the  patients  from  the  operative  cure  of 
their  myopia  are  very  great.  Not  merely  do  they  become  sometimes 
emmetropic,  but  the  acuteness  of  vision  is  usually  increased  in  a  remarkable 
degree,  being  occasionally  even  double  or  treble  that  which  previously 
existed  with  the  correcting  glasses.  This  improvement  is  chiefly  due 
to  the  increased  size  of  the  retinal  images.  The  reduction  in  the  refraction 
is  much  greater  in  these  cases,  than  after  removal  of  the  lens  for  cataract 
in  an  emmetropic  eye.  In  the  latter  case  a  convex  lens  of  10  D  is  required 
to  correct  the  eye  for  distance,  whereas  a  myope  of  20  D  most  commonly 
requires  no  correction  for  distance  after  the  removal  of  his  lens.  The 
explanation  of  this  is  simple.  When  the  lens  is  removed,  the  only  re- 
fracting surface  then  is  the  cornea,  the  focal  length  of  which  is  approxi- 
mately 31  mm.  ;   a  myopic  eye  therefore  which  is  31  mm.  long  would,  when 


428  DISEASES   OF   THE   EYE.  [chap.  xvi. 

deprived  of  its  lens,  bring  parallel  rays  to  a  focus  on  the  retina  «,nd 
would  require  no  correction  for  distance.  Since  the  average  focal  length 
of  the  emmetropic  eye  is  24  mm.  this  myopic  eye  would  be  31  —  24  = 
7  mm.  longer  than  the  emmetropic  eye.  Now  it  can  be  easily  shown  that, 
in  the  complete  eye  containing  the  lens,  every  millimetre  of  increase  in 
length  corresponds  with  an  increase  of  3  D  of  refraction,  consequently 
in  this  case  before  operation,  when  the  lens  was  present,  the  refraction 
would  have  been  increased  by  3  x  7  =  21  D,  a  result  which  agrees  in 
most  cases  with  practice. 

In  the  absence  of  the  lens  an  increase  of  1  mm.  in  length  of  the  eyeball 
only  augments  the  refraction  of  about  1*5  D,  that  is  to  say,  only  half  the 
amount  which  the  same  increase  of  length  produces  in  the  complete  eye.  A 
simple  rule,  therefore,  for  finding  approximately  what  the  refraction  will 
be,  after  removal  of  the  lens,  in  a  given  case  of  myopia,  is  to  take  half  the 
nianber  of  dioptres  of  the  myopia  and  subtract  it  from  10.  If  the  result 
be  positive  a  plus  lens  will  be  required  after  operation,  and  if  negative 
a  concave  lens.  For  example,  a  myope  of  10  D  will  require  a  +  5  D, 
for  correction  after  operation,  10  —  V"  =  5,  and  a  myope  of  30  D  will 
remain  with  5  D  of  myopia,  10  —  "V^  =  —  5.  In  practice  cases  some- 
times occur  which  do  not  fall  in  with  this  theory,  and  for  this  there  are 
reasons  which  cannot  be  fully  entered  into  here,  but  amongst  them  is 
the  difficulty  of  an  exact  estimation  of  the  refraction  in  high  M.  and  the 
possibility  of  the  M.  being  not  merely  axial,  but  also  caused  by  shortening 
of  the  focal  length  of  the  dioptric  system. 

The  mere  possibility  that  detachment  of  the  retina  may  be  caused,  or 
hastened,  by  the  operation  is  a  sufficient  reason  for  limiting  the  operation 
to  one  eye.  It  is  wiser  not  to  operate  on  the  second  eye,  even  though  a 
successful  result  may  have  been  obtained  in  the  first,  and  though  the 
patient,  as  often  happens,  may  desire  the  operation.  The  eye  which  has 
been  operated  upon  will  serve  for  distant  vision  and  its  fellow  for  near  work, 
and  thus,  where  the  eye  after  operation  becomes  emmetropic,  the  patient 
is  rendered  independent  of  glasses.  It  has  not  been  proved  that  re- 
moval of  the  lens  arrests  the  progress  of  myopia.  Many  ophthalmologists 
do  not  now  regard  this  operation  with  favour,  but  we  employ  it  for 
selected  cases,  in  one  eye  only. 


Hypermetropia. 

Definition,  and  Optical  Causes. — In  Hypermetropia  the  retina 
lies  in  front  of  the  principal  focus  of  the  dioptric  system,  and  there- 
fore parallel  rays  of  light  {a,  b,  Fig.  160),  falling  into  the  hyper- 
metropic eye  (E),  do  not  meet  on  the  retina,  but  converge  towards  a 
point  (c)  situated  behind  it.  As  compared  with  emmetropia  the 
refraction  of  a  hypermetropic  eye  is  diminished.  It  may  be  caused 
by  displacement  of  the  retina  forwards,  from  shortening  of  the  eye- 
ball (Axial  H.),  or  by  elon.iTatiou  of  tlie  focal  length  of  the  dioptric 


CHAP.    XVI.  J 


H  YPERMETROPIA . 


429 


system  tlirougli  flattening  of  tlie  cornea  (Curvature  H.),  absence  of 
the  lens  (dislocation,  cataract  extraction),  or  diminution  of  the 
refractive  index  of  the  lens  in  old  age  (senile  hypermetropia). 


Fig.    160. 

Far  Point  (R.)  of  the  Hypermetropic  Eye.— Since  paralleljays 
do  not  unite  on  the  retina,  but  produce  there  a  circle  of  diffusion 
{d,  e,  Fig.  160),  the  hypermetropic  eye  cannot  see  distant  objects  dis- 
tinctly, and  if  an  object  be  brought  closer,  its  focus  will  lie  still  farther 
behind  the  retina  (§  17,  chap.  xv.).  There  is  therefore  no  position 
between  infinity  and  the  cornea,  from  which  rays  of  light  would 
unite  on  the  retina  of  the  hypermetropic  eye  ;  in  other  words,  there 
is  no  real  far  point.  What  kind  of  rays  then  do  come  to  a  focus  on 
the  retina  of  a  hypermetropic  eye  ?  The  answer  will  be  found  by 
considering  the  course  of  the  rays  emerging  from  the  eye.  Since 
the  refraction  is  deficient  or,  what  is  the  same  thing,  since  the 
retina  lies  in  front  of  the  principal  focus  F.  Fig.  161  (§  18,  chap,  xv.), 
rays  coming  from  any  point  (c),  will  not  even  be  rendered  parallel, 


Fig.   IGl, 


but  will  pass  out  as  divergent  rays  (/,  g) ,  and  they  can  therefore  never 
meet  to  form  a  real  conjugate  focus,  or  far  point.  But  they  will 
diverge  as  if  they  came  from  a  point  R,  situated  behind  the  eye, 
which  point  is  the  virtual  conjugate  focus  of  the  point  c  on  the  retina. 


430  DISEASES   OF    THE   EYE.  [fTiAP.   xvi. 


R  is  the  virtual  far  point.  It  is  situated  behind  the  eye,  is  negative, 
and  cannot  be  measured  directly  as  in  myopia.  Conversely,  if  the 
rays  /,  j/,  enter  the  eye  with  a  convergence  towards  R,  they  will  unite 
on  the  retina.  The  hypermetropic  eye  therefore  is  only  adapted, 
when  at  rest,  for  convergent  rays.  The  shorter  the  eyeball,  the 
farther  the  retina  is  from  F,  and  the  greater  the  divergence  of  the 
emerging  rays,  and  consequently  the  shorter  will  be  the  distance  of 
the  far  point,  and  the  higher  the  error  of  refraction.     In  hyper- 

metropia,  as  in  myopia,  /•  =  — ,  but  here  R  is  negative,  and  therefore 

r,  the  error  of  refraction,  is  also  a  negative  quantity. 


Fig.    162. — Correction  of  hypernietropia.     R   =  far  point,  r  =  error 
of  refraction. 

Optical  Correction  of  Hypernietropia. — In  order  to  correct 
hypermetropia — that  is,  to  render  the  eye  emmetropic,  so  that 
parallel  rays  may  be  brought  to  a  focus  on  the  retina  (c,  Fig.  162) — 
a  lens  must  be  placed  in  front  of  the  eye,  which  will  give  to  the 
parallel  rays  {a,  h)  before  they  enter  it  a  convergence  towards  its 
far  point,  R.  This  lens  must  therefore  be  a  converging  or  +  lens, 
and  its  focal  length  must  be  equal  to  the  distance  of  R  from  the 
eye  (in  this  case  25  cm.).  The  negative  error,  or  deficiency  in  the 
refraction,  is  corrected  by  a  -j-  lens  (L),  which  increases  the  refrac- 
tion, and  thereby  shortens  the  focal  length  of  the  eye  so  as  to  bring 
the  focus  on  to  the  retina.  The  shorter  the  antero-posterior  axis 
of  the  eyeball,  the  closer  is  R,  and  the  shorter  therefore  must  be  the 
focal  length  of  the  correcting  lens.  That  is  to  say,  the  correct- 
ing lens  must  be  stronger,  and  the  hypermetropia  consequently 
greater,  when  the  eye  is  shorter. 


CHAr.  xvT.l  HYPERMETROPIA.  431 

It  is  evident  that  the  farther  the  lens  (J.)  is  from  the  cornea  the 
greater  is  its  distance  from  R,  and  therefore  the  weaker  the  lens 
which  is  required.     This  is  the  reverse  of  what  takes  place  in  myopia 

(p.  ^17). 

Hypermetropia  can  also  be  corrected  by  an  effort  of  accommo- 
dation, in  which  the  increased  convexity  of  the  crystalline  lens 
within  the  eye  takes  the  place  of  the  correcting  glass.  In  the  case 
represented  by  Fig.  162,  an  accommodation  equivalent  to  4  D  would 
be  required. 

Determination  of  the  Degree  of  H.  Subjective  Method  by 
TRIAL-LENSES  AND  TEST-TYPES. — Since  accommodation  tends  to 
correct  hypermetropia,  care  must  be  taken  in  drawing  conclusions 
from  this  method  of  examination.  If  the  acuteness  of  vision  be 
improved  by  a  convex  lens,  H.  is  present,  but  it  may  be  found  that, 
with  a  lens  of  some  dioptres  less,  the  eye  will  see  equally  well ;  this 
means  that  an  effort  of  accommodation  supplements  the  weaker 
lens  placed  before  the  eye.  As  higher  lenses  are  proceeded  to,  the 
effort  of  accommodation  is  relaxed,  until,  finally,  the  strongest  lens 
wdth  which  vision  is  still  at  its  best  is  reached,  when,  it  may  for  the 
present  be  assumed,  no  further  efiort  of  accommodation  is  made, 
and  this  lens  then  represents  the  whole  error  of  refraction. 

In  low  degrees  of  hypermetropia,  accommodation  frequently 
corrects  the  whole  of  the  H.  When  such  an  eye  is  found  to  have 
full  vision  without  a  glass,  a  beginner  may  fall  into  the  error  of 
regarding  it  as  emmetropic  ;  but  if  he  take  the  precaution  of  placing 
a  low  convex  lens  in  front  of  it,  and  then  finds  that  the  acuteness  of 
vision  remains  as  good  as  without  the  glass  (because  the  effort  of 
accommodation  is  now  relaxed),  he  will  avoid  this  mistake,  unless 
there  should  be  tonic  cramp  of  accommodation,  which  might  partially, 
or  even  completely,  mask  the  hypermetropia. 

If  a  glass  a  single  number  higher  than  the  exact  measure  of  the 
defect  be  placed  before  the  eye,  vision  again  becomes  indistinct, 
because  the  rays  are  then  brought  to  a  focus  in  front  of  the  retina, 
and  a  circle  of  diffusion  is  formed  on  the  latter.  The  eye,  in  fact, 
is  put  by  such  a  glass  in  a  condition  of  myopia.  Therefore  the 
strongest  convex  glass  with  which  a  hyfermetrofic  eye  can  see  distant 
objects  (the  test-types)  jnost  distinctly  is  the  glass  which  corrects  its 
hypermetropia,  and  is  the  measure  of  the  latter.  Very  commonly  it 
is  only  the  manifest  hypermetropia  {vide  infra)  which  is  ascertained 


432  DISEASES   OF   THE  EYE.  [oiiap.  xvi. 


by  this  method,  unless  the  accommodation  has  been  previously 
paralysed  by  atropine. 

Objective,  or  Ophthalmoscopic  Methods.  Direct  Method  at  a 
Distance. — The  retinal  vessels  are  visible,  and  appear  to  move  in 
the  same  direction  as  the  motion  of  the  observer's  head. 

Indirect  Method. — The  optic  disc  appears  to  diminish  in  size  as 
the  lens  is  withdrawn  from  the  patient's  eye. 

Direct  Method. — The  strongest  convex  glass  with  which  the 
fundus  and  vessels  can  be  seen  distinctly  is  the  measure  of  the  H. 

Retinoscopij. — With  a  flane  mirror  the  shadow  moves  in  the  same 
direction  as* that  in  which  the  mirror  is  rotated,  that  is  to  say,  with 
the  mirror. 

Amplitude  of  Accommodation  in  Hypsrmstropia. — When  at  rest  the 
refraction  of  the  hypermetropic  eye  is  deficient,  consequently  r  must  be 
negative  (  —  r),  and  the  amplitude  of  accommodation  must  include  the 
correction  required  to  adapt  the  eye  to  infuiity  ;  therefore  the  formula 
for  the  amplitude  of  accoinmodation  (p.  6)  becomes 

a  =  p  —  {  —  r)    =  f  -\-  r. 

For  example  :  if  the  punctum  proximum  of  a  hypermetropic  eye  of 
5  D  be  at  30  cm.,  what  is  the  ainplitude  of  accommodation  ?  5  D  (  =  r) 
is  necessary  in  order  to  make  the  eye  emmetropic,  and  to  accommodate 
the  emmetropic  eye  to  30  cm.  3*25  D  ('yV  =  3'25)  is  required.  Hence 
a  =  3-25  +  5  =  8-25  D. 

Range  of  Accommodation  in  H. — In  hypermetropia  a  part  of  the 
patient's  amplitude  of  accommodation  is  used  to  correct  the  error  of 
refraction,  the  remainder  only  being  available  for  the  purpose  of  adapting 
the  eye  for  a  near  point.  It  follows,  therefore,  that,  with  the  same  ampli- 
tude of  accommodation  as  an  emmstrope,  the  near  point  will  be  farther 
away  from  the  eye  in  hypermetropia.  This  is  shown  in  Fig.  157,  which 
represents  the  ranges  of  accommodation  in  emmetropia  (E.),  myopia  of 
3  D  (M.),  and  hypermetropia  of  3  D  (H.),  the  amplitude  being  8  D. 

Th3  Angle  y  in  Hypermetropia. — In  hypermetropia,  as  in  emmetropia, 
the  cornea  is  cut  to  the  inside  of  its  axis  by  the  visvial  line  ;  but  in  hyper- 
metropia the  angle  which  the  visual  line  forms  with  the  optic  axis  is  greater, 
owing  to  the  shortness  of  the  eyeball,  the  effect  of  which  is  to  incease 
the  angular  distance  between  the  macula  lutea  and  the  optic  axis  {O  A, 
Fig.  158).  Consequently,  in  extreme  cases,  when  the  two  visual  lines  of 
a  hypermeti-opic  individual  are  directed  to  an  object,  the  axes  of  the  cornese 
may  seem  to  diverge,  and  thus  the  appearance  of  a  divergent  strabismus 
will  be  given  (see  apparent  strabismus,  chap,  xvii.). 

Varieties  of  H.  in  Relation  to  Accommodation.— Hypermetropes 

endeavour  to  correct  as  much  of  the  error  of  refraction  as  possible 


CHAP.  XVI.]  HYPERMETROPIA.  433 

by  accommodating,  and  the  ciliary  muscle  is  thus  kept  persistently 
contracted  even  though  the  visual  axes  remain  parallel. 

In  young  persons  this  spasm  is  not,  or  may  be  only  partially, 
relaxed  when  the  correcting  convex  glass  is  held  before  the  eye, 
and  consequently  the  whole  or  part  of  the  hypermetropia  may  be 
masked  by  the  cramp.  That  part  of  the  hypermetropia  which  is 
thus  masked  is  called  latent  (HI.),  while  the  part  which  is  revealed 
by  the  convex  glass  with  which  the  test-types  are  read  is  called 
manifest  (Hm.).  The  entire  hypermetropia  is  made  up  of  the  latent 
and  manifest  H.  (H.  =  Hm.  +  HI.). 

If  the  Hm.  cannot  be  corrected  by  accommodation  it  is  called 
absolute  H.,  if  it  can  be  so  corrected  it  is  known  as  facultative. 
For  example,  a  patient  without  glasses  has  V  =  yg,  and  with  + 
r5  D,  V  =  f ;  with  2'5  D  also,  V  =  J,  but  when  accommodation 
is  paralysed  the  H.  is  found  to  be  4  D.  In  this  case  the  total 
H.  is  4  D,  the  Hm.  is  2*5  D,  of  which  Vb  D  is  absolute  and  1  D 
facultative,  while  there  is  TS  D  latent  H.  The  relation  between 
the  Hm.  and  H.  varies  with  the  age  and  general  health  of  the 
individual. 

When  the  spasm  persists  so  that  the  accommodation  cannot  be 
relaxed,  the  vision  is  then  made  worse,  even  by  a  weak  convex 
glass,  thus  simulating  emmetropia.  We  then  say  that  the  whole 
hypermetropia  is  latent.  Or,  in  extreme  cases  of  accommodative 
spasm,  parallel  rays  may  be  united  in  front  of  the  retina,  and  the 
eye  made  apparently  myopic,  distant  vision  being  actually  capable 
of  improvement  by  concave  glasses.  Some  of  these  patients  cannot 
maintain  a  sustained  view  of  an  object  at  any  distance  without 
suffering  pain  in  and  about  the  eyes.  Examination  with  the  ophthal- 
moscope, or  paralysis  of  accommodation  with  atropine,  will  enable 
the  surgeon  to  avoid  mistakes. 

In  order  to  relieve  this  cramp,  or  to  ascertain  the  real  state  of 
the  refraction,  especially  in  children,  atropine  must  be  freely  in- 
stilled ;  and  it  will  often  be  necessary  to  keep  the  accommodation 
paralysed  for  some  days,  and  to  commence  the  use  of  the  correcting 
spectacles  before  the  effect  of  the  atropine  begins  to  wear  off.  In 
this  way  a  recurrence  of  the  spasm  may  be  often  prevented. 

As  life  advances,  and  the  power  of  accommodation  diminishes, 
the  manifest  part  of  the  hypermetropia  increases,  while  the  latent 
part  decreases,  until  finally  Hm.  =  H. 
28 


434  DISEASES   OF    THE   EYE.  [chap.  xvi. 

Etiology.— Typical  hyperinetropia  is  practically  always  axial— 
i.e.  due  to  a  short  eyeball.  Children  are  hypermetropic  at  birth, 
but  with  growth  of  the  body  the  eye  develops  and  becomes  less 
hypermetropic,  or  emmetropic,  or  even  myopic.  So  that  the  hyper- 
metropic eye  may  be  regarded  as  an  undeveloped  organ,  and  indeed 
the  highest  degrees  of  H.  are  met  with  in  very  small  (microphthalmic) 
eyes,  which  are  often  the  subjects  of  congenital  malformations. 
The  eyes  of  animals  and  of  uncivilised  nations  are  hypermetropic. 
When  the  period  of  growth  ceases,  any  H.  which  may  then  exist 
remains  stationary.  There  is  never  any  progress,  as  in  myopia  ; 
and  very  high  degrees  are  rarely  seen,  even  12  D  being  unusual. 
Hypermetropic  eyes  are  moreover  healthy,  and  free  from  the  com- 
plications which  follow  mechanically  from  the  change  in  shape  of 
the  myopic  eye. 

Symptoms  and  Signs  of  H.— These  depend  chiefly  on  the  relation 
of  the  H.  to  the  amplitude  of  accommodation,  and  will  be  under- 
stood from  what  has  been  already  stated.  Both  distant  and  near 
vision  may  be  perfect,  or  near  vision  alone  may  be  defective,  or  both 
may  be  imperfect.  In  high  degrees  of  H.  patients  sometimes  hold 
the  book  close  to  the  eyes  in  order  to  obtain  larger  retinal  images, 
but  they  cannot  read  the  smallest  type  with  the  ease  and  fluency 
of  the  myope.  Even  with  correction,  vision  is  often  defective  in 
these  cases,  more  especially  if  astigmatism  be  present  in  addition 
to  the  H.  Slight  redness  and  veiling  of  the  edges  of  the  optic  disc 
with  tortuosity  of  the  retinal  vessels  is  sometimes  seen,  and  must 
not  be  mistaken  for  optic  neuritis.  The  normal  appearance  of  the 
retina  known  as  "  shot  silk  "  is  better  marked  and  of  more  frequent 
occurrence  in  young  hypermetropes  than  in  other  conditions  of 
refraction.  Hypermetropic  eyes  show  increased  curvature  of  the 
sclerotic  at  the  outer  side,  when  the  eye  is  rotated  inwards,  the 
pupils  are  smaller  than  in  Em.,  and  the  anterior  chamber  is  shallow. 
Other  consequences  are  accommodative  asthenopia,  and  convergent 
strabismus. 

Accommodative  Asthenopia  (u,  priv. ;  aOivo^,  strength ;  wi//).— 
This  is  the  name  given  to  the  group  of  symptoms  which  occur  when 
the  patient  is  unable  to  sustain  the  accommodative  effort  required 
for  near  vision.  A  hypermetrope,  having  used  up  part  of  his 
accommodation  for  distance,  has  for  near  objects  actually  less  at 
his  disposition  than  an  emmetrope.     Hence,  hypermetropic  people 


CHAr.  XVI.]  HYPERMETROPIA.  435 


often  complain  of  inability  to  sustain  aLconiniodative  eHoits  for 
near  objects  for  any  length  of  time.  After  reading,  sewing,  etc., 
for  a  short  time,  sensations  of  pressure  in  the  eyes,  of  weight  above 
and  around  them,  and  more  or  less  pains  in  the  brow  and  temples, 
come  on,  and  the  words  or  stitches  become  indistinct,  and  cannot 
be  distinguished,  and  the  efforts  to  see  are  attended  with  lacrimation, 
frowning,  and  even  with  facial  contortions.  The  work  must  then 
be  interrupted,  and  after  a  few  minutes'  rest  it  can  be  resumed,  but 
must  soon 'again  be  given  up.  After  a  Sunday's  rest  the  patient 
is  often  able  to  get  on  better  than  on  the  previous  Saturday.  These 
symptoms  depend  simply  upon  inability  of  the  ciliary  muscle  to 
answer  to  the  excessive  demands  made  upon  it. 

Accommodative  asthenopia  often  appears  suddenly  during  or 
after  illness,  the  explanation  being  that,  although  hypermetropia  had 
always  existed,  yet  in  health  the  ciliary  muscle  was  equal  to  the 
great  efforts  required  of  it,  but  in  sickness  it  shared  the  debility 
of  the  system  in  general. 

Internal,  or  Convergent  Concomitant  Strabismus.— This  con- 
dition has  a  certain  relation  to  hypermetropia.  It  will  be  treated 
of  in  the  chapter  on  the  Motions  of  the  Eyeballs  and  their  Derange- 
ments (chap.  xvii.). 

The  Prescribing  of  Spectacles  in  Hypermetropia.— If  a  person 
be  found  to  be  hypermetropic,  but  his  acuteness  of  vision  without 
glasses  be  good,  or  as  good  as  he  desires,  and  he  complain  of  no 
asthenopic  symptoms,  glasses  need  not,  indeed  should  not,  be  pre- 
scribed for  him.  No  harm  will  come  to  his  eye  from  his  going 
without  glasses. 

If  the  patient  complain  of  imperfect  distant  vision  due  to  hyper- 
metropia, then  those  lenses  w^hich  correct  the  Hm.  may  be  pre- 
scribed for  distant  vision,  to  be  worn  either  constantly  or  occasion- 
ally, as  he  may  desire.  Such  a  patient  is  almost  certain  to  complain 
also  of  accommodative  asthenopia  ;  while  many  patients  will  be 
met  with  who  complain  of  the  latter,  yet  express  themselves  as  per- 
fectly satisfied  with  their  distant  vision.  For  relief  of  their  asthen- 
opia it  is  usually  enough  to  prescribe  spectacles  for  near  work  which 
will  correct  the  Hm.,  along  with  1  D  or  2  D  of  the  HI,  if  the  latter 
exist. 

If  there  be  excessive  cramp  of  accommodation,  or  strabismus, 
glasses  to  correct  the  whole  hypermetropia  should  be  worn  while 


436  DISEASES   OF   THE   EYE.  [chap.  xvi. 


the  eye  is  under  atropine ;  and  afterwards  as  much  of  tlie  111.  as 
possible,  along  with  the  Hm.,  should  be  corrected  by  glasses  to  be 
worn  constantly. 

Astigmatism. 

In  this  form  of  ametropia  the  refracting  surfaces  are  not  spheri- 
cal, and  consequently,  rays  of  light  from  a  luminous  point  are  not 
brought  to  one  focus.  The  defect  usually  lies  in  the  cornea,  and  the 
astigmatism  may  be  regular  or  irregular. 

In  Hegular  Astigmatis7n,  which  is  congenital,  the  directions  of 
the  greatest  and  least  curvatures  of  the  cornea  are  always  at  right 
angles  to  each  other,  and  usually  fall  precisely  in  the  vertical  and 
horizontal  meridians,  the  meridian  of  greatest  curvature  being  most 


Fig.   103. 

frequently  the  vertical.  The  surface  of  the  cornea  then  resembles 
the  back  of  the  bowl  of  a  spoon,  which  is  more  convex  from  side  to 
side  than  from  heel  to  point.  Astigmatism  is  said  to  be  ''  with  the 
rule  "  when  the  meridian  of  greatest  curvature  is  vertical,  and 
"  against  the  rule  "  when  this  meridian  is  horizontal.  Hence  a 
pencil  of  rays  passing  into  the  eye,  instead  of  meeting  at  a  common 
focus,  is  refracted  in  such  a  way  that  the  rays  passing  through  the 
vertical  meridian  of  the  cornea  are  brought  to  a  focus  much  earlier 
than  those  which  fall  through  its  horizontal  meridian. 

Fig.  163  shows  the  different  forms  which  the  image  of  a  point 
assumes  after  the  passage  of  the  rays  through  an  astigmatic  surface. 

At  A  neither  vertical  {v  v')  nor  horizontal  {h  h')  rays  have  yet 
been  united  at  their  foci,  but  the  vertical  rays  are  the  nearest  to 
their  focus  ;  and  therefore  here  the  appearance  of  the  image  on  an 
intercepting  screen,  is  an  oval  with  its  long  axis  horizontal,  as  shown 
by  the  dotted  line.  At  B  the  vertical  rays  have  met  at  their  focus, 
but  the  horizontal  rays  not  as  yet  at  theirs,  the  effect  being  a  hori- 


CHAP.    XVT.] 


ASTIGMATISM. 


437 


zontal  straight  line.  At  C  the  vertical  rays  are  diverging  again 
from  their  focus,  and  the  horizontal  rays  have  not  come  to  theirs. 
At  D  the  same  conditions  exist,  only  a  little  farther  on,  where  one 
set  of  rays  is  diverging,  the  other  still  converging,  but  each  at  the 
same  angle  ;  hence  the  figure  is  a  circle.  At  F  the  horizontal  rays 
have  met,  and  the  result  is  a  vertical  straight  line.  At  G  both  sets 
of  rays  are  divergent,  and  the  figure  is  an  oval  with  the  long  axis 
perpendicular.  An  astigmatic  eye  has,  therefore,  two  foci,  each 
being  represented  l)y  a  line,  and  not  by  a  point.  The  interval  be- 
tween the  foci  of  the  two  principal  meridians  (B  and  F,  Fig.  163)  is 
called  the  Focal  Interval  and  is  a  measure  of  the  astigmatism. 

There  are  various  kinds  of  regular  astigmatism,  according  to 
the  position  of  the  two  principal  foci  with  reference  to  the  retina, 
as  follows  : — 

1.  Compound  Hypermetropic  Astigmatism. — Both  foci  behind  the 


Fig.   164. 


Fia.   165. 


retina,  that  of  the  horizontal  rays  (H,  Fig.  164)  farther  back  than 
that  (V)  of  the  vertical  rays.  Hypermetropia  in  both  meridians, 
but  greater  in  the  horizontal. 

2.  Simple  Hypermetropic  Astigmatism. — The  focus  of  the  vertical 
rays  (V,  Fig.  165)  on  the  retina  (emmetropia  in  that  meridian)  ; 
that  of  the  horizontal  rays  (H)  behind  the  retina  (hypermetropia  in 
that  meridian). 

3.  Mixed  Astigmatism. — The  horizon- 
tal focus  (H,  Fig.  166)  behind  the  retina 
(hypermetropia  in  that  meridian),  and 
the  vertical  focus  (V)  in  front  of  the 
retina  (myopia  in  that  meridian). 

4.  Simple  Myopic  Astigmatism,. — The 
horizontal  focus  (H,  Fig.  167)  on  the  retina  (emmetropia  in  that 
meridian),  the  vertical  focus  (V)  in  front  of  the  retina  (myopia). 


438 


DISEASES   OF    THE   EYE. 


[chap.    XVI. 


5.  Compound  Myopic  Astigmatism. — Both  foci  in  front  of  the 
retina,  but  the  vertical  focus  farther  forward  (V,  Fig.  168). 


Fig.   IC)-; 


Fig.   168. 


Symptoms  of  Regular  Astigmatism.— We  may  conclude  that 
an  individual  is  astigmatic  if  he  see  horizontal  (or  vertical)  lines, 
such  as  the  horizontal  portions  of  Roman  capital  letters,  or  the 
horizontal  lines  in  music,  or  the  horizontal  rays  in  Snellen's  Sunrise 
figure  (see  end  of  this  book)  distinctly,  while  the  vertical  (or  horizon- 
tal) lines  seem  indistinct.  Patients  seldom,  however,  complain  of 
this  peculiarity  in  their  vision. 

To  explain  the  perception  of  lines  by  an  astigmatic  eye,  let  us 
suppose  an  eye  to  be  emmetropic  in  the  vertical  meridian,  and 
ametropic  in  the  horizontal  meridian  ;  we  must  first  consider  how 
a  point  will  be  seen  by  such  an  eye.  The  rays  of  light  emitted  from 
the  point  and  passing  through  the  horizontal  meridian  will  not  be 
brought  to  a  focus  on  the  retina,  but  will  produce  a  blurring  of  the 
retinal  image  of  the  point  at  each  side  ;  while  the  vertical  rays  will 
unite  on  the  retina,  and  consequently  the  point  will  appear  distinctly 
defined  above  and  below. 

Now,  a  line  may  be  regarded  as  a  number  of  points,  and  it  is 
only  necessary  therefore  to  arrange  a  number  of  points,  blurred  at 


J? 


^  6 


CL 


Fig.   169. 


Fig.   170. 


the  sides,  in  horizontal  and  vertical  lines — as  at  a  and  h  in  Fig.  169. 
It  is  evident  at  once,  from  mere  inspection,  that  the  horizontal  Kne 
will  appear  distinct,  because  the  rays  wliich  diverge  from  each  point 
of  the  latter  in  a  vertical  plane — i.e.  at  right  angles  to  the  direction 


CHAP.  XVI.]  ASTIGMATISM.  439 


of  the  line — are  brought  to  a  focus  on  the  retina  ;  while  those  rays 
diverging  in  a  horizontal  plane,  although  not  meeting  on  the  retina, 
do  not  render  the  picture  of  the  line  indistinct,  because  the  diffusion 
images  resulting  from  them  exist  in  the  horizontal  direction,  and 
consequently  cover  or  overlap  each  other  on  the  line,  and  therefore 
are  not  seen,  and  do  not  confuse  the  sight.  At  the  ends  of  the  line 
only  (6,  Fig.  170)  do  the  diffusion  images  cause  a  fuzziness  or  make 
the  line  seem  longer  than  it  is.  In  this  case  a  vertical  line  {a,  Figs. 
169  and  170)  seems  indistinct,  because,  the  horizontal  meridian  being 
out  of  the  focus,  the  diffusion  images  existing  in  that  direction  are 
very  apparent,  as  they  are  at  right  angles  to  the  edge  of  the  line. 
On  the  other  hand,  in  order  to  see  a  vertical  stripe  accurately,  it 
is  necessary  only  that  the  rays  diverging  in  a  horizontal  plane  should 
have  their  focus  on  the  retina  ;  and,  therefore,  if  an  individual  can 
only  see  vertical  lines  distinctly  at  6  metres  we  know  that  his  eye 
is  emmetropic  in  the  horizontal  meridian  (and  probably  myopic 
in  the  vertical  meridian).  We  do  not,  however,  hear  this  complaint 
as  often  as  might  be  expected,  because  simple  astigmatism  is  not 
so  common  as  one  or  other  of  the  compound  forms. 

Astigmatic  people  do  not  generally  see  very  distinctly,  either 
at  long  or  at  short  distances. 

Even  in  hypermetropic  astigmatism  the  book  is  very  often 
brought  close  to  the  eyes,  in  order,  by  increasing  the  size  of  the 
retinal  image,  to  make  up  for  its  indistinctness. 

Astigmatic  individuals  frequently  suffer  much  from  headache, 
and  sometimes  from  regular  attacks  of  migraine  with  sickness,  due 
to  constant  effort  to  see  distinctly,  and  correction  of  the  astigmatism 
often  effects  a  cure. 

It  has  been  stated  that  epilepsy,  hysteria,  and  neurasthenia,  if 
not  capable  of  being  actually  produced  by  refractive  errors,  especially 
by  astigmatism,  in  persons  with  stable  brains,  may  sometimes  have 
such  errors  as  their  exciting  cause,  where  there  is  already  a  pre- 
disposition to  the  disease. 

All  these  signs  and  symptoms  appertain  to  the  rather  high  de- 
grees of  astigmatism.  Slight  degrees  may  cause  no  annoyance 
beyond  some  indistinctness  of  vision  ;  and  indeed  slight  degrees  of 
hypermetropic  astigmatism  often  pass  unnoticed  until  late  in  life, 
when  the  accommodation  begins  to  fail.  But  very  low  degrees  of 
astigmatism  may  give  rise  to  symptoms  in    neurotic    individuals. 


440  DISEASES    OF    THE   EYE.  [chap.  xvi. 

The  forms  of  Astigmatism  most  likely  to  cause  annoyance  are 
those  contrary  to  rule  or  with  the  axis  obliquely  placed. 

We  are  often  led  to  suspect  and  to  seek  for  astigmatism  when, 
in  examining  the  refraction  with  spherical  glasses,  we  are  able  to 
bring  about  some  improvement  of  vision,  but  cannot  obtain  normal 
V.  with  any  glass,  while  there  is  no  organic  disease  to  account 
for  the  defect.  Also  if,  in  examining  with  spherical  glasses,  we 
find  V.  benefited  equally  by  several  glasses  of  considerable  differ- 
ence in  power,  even  perhaps  by  convex  as  well  as  by  concave  glasses. 

The  ophthalmoscope  affords  an  admirable  means  of  diagnosing 
astigmatism,  and  of  determining  its  amount.  Just  as  the  astigmatic 
eye  cannot  see  horizontal  and  vertical  lines  equally  well  at  the  same 
moment,  so  is  an  observer  unable  to  see  both  the  vertical  and  hori- 
zontal vessels  in  the  retina  of  the  astigmatic  eye  simultaneously, 
but  must  alter  his  accommodation  to  be  able  to  see  first  one  set  of 
vessels  and  then  the  other. 

A  comparison  of  the  shape  of  the  optic  papilla,  as  seen  in  the 
upright  and  in  the  inverted  images,  may  also  give  a  clue  to  the 
presence  of  astigmatism.  Inasmuch  as  the  fundus  oculi  is  very 
much  magnified  in  the  upright  image  by  the  dioptric  media  through 
which  it  is  seen,  and  as  this  enlargement  is  greater  in  the  direction 
of  the  meridian  of  shortest  focus  (meridian  of  highest  refraction), 
which  is  most  commonly  the  vertical  meridian,  a  circular  object, 
such  as  the  papilla,  will  seem  to  be  of  an  oval  shape  with  its  long 
axis  vertical.  But  in  the  inverted  image,  if  tlie  principal  focus  of 
the  lens  be  closer  to  the  eye  than  13  mm.  (anterior  focus  of  the 
eye),  the  magnification  will  be  less  in  the  meridian  of  greatest  re- 
fraction ;  and  here,  consequently,  the  round  optic  papiUa  is  seen  as 
an  oval  with  its  long  axis  horizontal.  If  the  principal  focus  of  the 
lens  be  farther  from  the  eye  than  13  mm.,  the  magnification  again 
becomes  greater  in  the  meridian  of  greatest  refraction,  and  the 
oval  again  becomes  vertical.  Sometimes  the  papilla  is  really  of  an 
oval  shape,  and  not  round,  and  then  the  diagnosis  is  readily  made 
by  observing  that  in  one  image  it  is  seen  as  an  oval,  while  in  the 
other  image  it  is  circular.  Care  must  be  taken  in  the  indirect 
method  not  to  hold  the  lens  obliquely,  as  this  would  be  sufficient  to 
make  a  circular  disc  appear  oval,  the  long  axis  of  the  oval  being  in 
the  direction  of  the  axis  round  which  the  lens  is  rotated. 

In  astigmatic  eyes  a  crescent,  similar  to  that  seen  in  myopia, 


CHAP.  XVI.]  ASTIGMATISM.  441 

is  often  present  at  the  margin  of  the  optic  disc.     The  length  of  the 
crescent  is  parallel  to  the  meridian  of  least  refraction. 

In  cases  of  corneal  astigmatism  of  high  degree  the  image  of 
Placido's  disc  (p.  151),  reflected  on  the  cornea,  shows  ellipses  instead 
of  circles,  the  short  axes  lying  in  the  meridian  of  greatest  curvature. 

The  Estimation  of  the  Degree  of  Astigmatism  and  its  Correc- 
tion.— It  is  evident  that  to  correct  astigmatism  the  ordinary  spheri- 
cal lenses  would  be  of  little  use,  for  they  affect  the  refraction  of  the 
light  passing  through  them  equally  in  every  direction.  CyHndrical 
lenses  (p.  404)  are  therefore  employed,  which  refract  light  in  one 
direction  only — viz.  at  right  angles  to  their  axes. 

Subjective  Method. — Although  astigmatism  is  nowadays  al- 
most universally,  in  the  first  instance,  estimated  by  means  of  the 
ophthalmoscope,  or  by  the  astigmometer  (p.  443),  yet  in  order  to 
give  the  reader  a  clear  idea  of  the  matter  in  the  simplest  way,  a 
subjective  method  for  its  estimation  will  be  now  described,  while  its 
objective  estimation  by  aid  of  the  ophthalmoscope  (erect  image  and 
retinoscopy)  will  be  treated  of  in  the  next  chapter. 

Simple  Astigmatism. — Snellen's  Sunrise  {vide  diagram  at  end  of 
book),  or  some  such  diagram,  is  placed  at  6  metres  from  the  eye 
(the  other  eye  being  excluded),  and  the  patient  is  asked  whether  there 
be  any  line  which  he  sees  much  more  distinctly  and  blacker  than  the 
others,  and  can  trace  farther  towards  the  central  point.  If  that  be 
.so,  he  must  be  emmetropic  in  the  meridian  at  right  angles  to  that 
line,  provided  his  accommodation  be  at  rest,  and  ametropic  in  the 
meridian  corresponding  with  that  line. 

In  case  the  horizontal  line  below  at  each  side  be  the  distinct  one, 
the  eye  is  em.metropic  in  the  vertical  meridian,  and  probably  hyper- 
metropic in  the  horizontal  meridian,  because  the  latter  is  generally 
that  of  least  curvature.  Consequently,  a  convex  cylindrical  lens 
held  with  its  curvature  horizontally  (axis  vertical)  before  the  eye 
will  correct  the  defect.  The  highest  convex  cylindrical  glass  which 
renders  all  the  lines  equally  distinct  and  which  gives  the  patient  the 
best  possible  distant  vision  will  be  the  correcting  glass.  This  would 
be  a  case  of  Simple  Hypermetropic  Astigmatism  (As.  H.).  If  the 
lens  required  be  +  2  D  Cyl.,  it  would  be  As.  H.  2  D  ;  and  in  pre- 
scribing for  the  optician  we  would  write  "   +  2  D  Cyl.  Ax.  Vert." 

If  the  central  vertical  line  be  the  distinct  one,  then  emmetropia 
exists  in  the  horizontal  meridian,  and  probably  therefore  myopia  in 


442  DISEASES   OF    THE   EYE.  [chap.  xvi. 


the  vertical  meridian  ;  and  a  concave  cylindrical  lens  held  before  the 
eye  with  its  curvature  vertical  (axis  horizontal)  will  correct  the  de- 
fect. The  lowest  concave  cylindrical  lens  which  gives  the  patient 
the  best  possible  distant  vision  will  be  the  correcting  lens.  This 
would  be  a  case  of  Simple  Myopic  Astigmatism  (As.  M.).  If  the  lens 
be  —  2'5  Cyl.,  it  would  be  As.  M.  2*5  D  ;  and  for  the  optician  we 
should  write  ''  —  2-5  D  Cyl.  Ax.  Horiz." 

The  reader  should  now  make  a  few  experiments  for  himself  with 
cylindrical  lenses,  by  means  of  which  he  can  produce  artificial  astig- 
matism in  his  own  eye.  Let  him  place  Snellen's  Sunrise  figure 
opposite  his  eye  at  a  distance  of  about  4  to  6  metres.  If  he 
now  hold  a  -[-  I'O  Cyl.  before  his  eye,  with  its  axis  horizontal,  it 
gives  a  myopia  of  TO  D  to  the  vertical  meridian  of  the  eye, 
while  the  horizontal  meridian  remains  emmetropic ;  and  con- 
sequently, he  will  see  the  central  vertical  line  of  the  diagram  dis- 
tinctly, while  the  horizontal  lines  will  be  indistinct.  By  placing 
a  —  rO  Cyl.  with  its  axis  horizontal  before  the  eye,  in  addition 
to  the  +  I'O  Cyl.,  the  artificial  astigmatism  produced  by  the  latter 
is  corrected,  and  the  whole  diagram  becomes  distinct.  Every 
other  kind  and  degree  of  astigmatism  can  be  similarly  represented 
by  lenses  and  similarly  corrected. 

*  Co7npound  Astigmatism. — The  spherical  lens  which  corrects  one 
meridian  having  been  found,   one  set  of 

TT   4  T) 

lines  will  appear  defined,  and  then  the  + 
or  —  cylinder  necessary  to  bring  the  re- 

H.  5D.       maining   lines   into    focus    will  give    the 

amount    of   astigmatism.      In    the    case 

represented  by  Fig.  171  the  order  for  the 

Fig.  171.  glasses  would  read  ^'  +4  D  Sph.o+  1  D 

Cyl.    Ax.    Vert."  ^       This   is    Compound 

Hypermetropic   Astigmatism. 

In  an  analogous  way  the  examination  is  made  for  Compound 
Myopic  Astigmatism,  in  which  every  meridian  is  myopic,  but  the 
vertical  meridian  more  so  than  the  others. 

Mixed  Astigmatism. — In  a  case  of  mixed  astigmatism,  such  as  is 
represented  by  Fig.  172,  the  correction  can  be  made  in  two  ways  • 
(a)  by  a   Sph.  —    3    D,  which  will  correct  the   vertical  meridian, 

1   The  sign  O  indicates  ''  combined  with." 


CHAP.    XVI.] 


ASTIGMATISM. 


443 


M.  3D 


but  will  increase  the  liypermetropia  in  the  horizontal  meridian  by 

3  D,  making  it  8  D,  which  can  then  l^e  corrected  by  combining  a 

cylindrical  lens  of  +  8  D,  axis  vertical,  with 

the  above   spherical   lens  ;   (6)  by  a  spherical 

+  5   D,    which    will    correct   the    horizontal 

meridian,    but    will    increase  the   myopia  in H.D5 

the   vertical  meridian   to  8  D,   necessitating 

the    combination   of   a    —    Cyl.  lens  of  that 

number  with  the  +  5  D  8ph.     For  reading.  Fig.  172. 

writini)-,  etc.,  an  over-correction  of  the  hori- 

zontal  meridian  with  +  8  D  Cyl,  thus  rendering  the  eye  myopic  3 

D  in  every  meridian,  and  enabling  the  patient  to  read  at,  or  near, 

his  far  point,  might  be  the  most  suitable  arrangement. 

As  it  is  necessary,  in  order  to  test  the  degree,  etc.,  of  astigmatism 

accurately,  that  the  accommodation  be  at  rest,  it  is  desirable,  before 

the   examination   for   any   of 
Jt  jk.    y^"^  *^®    hypermetropic    forms    in 

young  persons,  to  instil  atro- 
pine into  the  eye. 

*  Measurement   of   the 
Degree  of  Astigmatism  by 

THE       ASTIGMOMETER. — T  h  i  S 

is  one  of  the  most  rapid  and 
satisfactory  methods  of  de- 
termining both  the  degree  of 
corneal  astigmatism,  and  the 
position  of  the  meridians  of 
greatest  and  least  refraction. 
The  cornea  reflects  images 
of  objects  in  the  same 
manner  as  a  convex  mirror, 
and  the  smaller  the  radius  of 
curvature  the  smaller  will 
be  the  image  of  any  given  object.  It  is  easy  to  calculate  the  radius 
of  curvature  of  the  cornea,  if  the  size  of  the  object,  its  distance 
from  the  cornea,  and  the  size  of  the  corneal  image  be  known.  The 
only  difficulty  lies  in  the  measurement  of  this  image  ;  and  it  has  been 
found  that  the  best  method  of  effecting  this  is  to  double  the  image 
by  means  of  prisms,  and  then  to  alter  the  strength  of  the  prism  until 


Fig.   173. — The  Astigmometer. 


444  DISEASES   OF    THE   EYE.  [chap.  xvi. 

the  two  images  just  come  into  contact.  When  this  has  taken  place, 
a  displacement  equal  to  the  size  of  the  image  has  been  produced. 
The  amount  of  displacement,  and  hence  the  size  of  the  image,  can 
easily  be  calculated.  This  is  the  principle  of  the  astigmometer 
(Fig.  173). 

In  order  to  measure  the  degree  of  astigmatism  by  this  instru- 
ment, we  do  not  require  to  know  the  radius  of  curvature  of  the 
cornea,  but  need  merely  find  out  the  difference  in  refractive  power 
between  tlie  meridians  of  greatest  and  least  curvature,  and  this 
the  instrument  enables  us  to  do  in  a  few  seconds  without  any 
calculation. 

The  Astigmometer. — It  consists  (Fig.  173)  of  a  telescope  {f)  con- 
taining a  double  refracting  prism  between  the  object  glasses,  and 
two  reflectors  or  mires  {k  and  I),  movable  on  an  arc  (m),  which  is 
fixed  to  the  telescope  tube.  The  latter  turns  on  its  own  axis,  and 
enables  the  arc  to  be  placed  in  any  meridian,  its  position  being  indi- 
cated on  a  graduated  circle  {g).  The  patient  places  his  chin  on  the 
rest  d,  and  looks  into  the  tube  at  /,  the  eye  which  is  not  under 
observation  being  covered  by  the  disc  e.  The  surgeon  then  looks 
through  the  telescope  at  w,  turns  the  arc  m  into  a  horizontal  position, 
and  observes  the  corneal  images  of  the  mires,  which  he  gets  into  focus. 
He  then  moves  the  mires  until  the  central  images  just  come  intjo  con- 


tact ;  the  four  images  will  then  occupy  the  relative  positions  shown  in 
Fig.  174.  The  arc  is  then  rotated  into  the  vertical  meridian,  and  if 
the  curvature  of  the  cornea  in  this  meridian  be  the  same  as  in  the 
horizontal  meridian,  the  central  images  will  still  appear  to  be  in  con- 
tact ;  but  if  the  radius  of  curvature  in  the  vertical  meridian  be  smaller, 
the  intervals  a  to  h  and  ci  to  V  will  diminish,  and  consequently  the 
central  images  will  overlap,  as  in  Fig.  175,  each  step  of  a'  representing 
a  difference  of  1  Dioptre.     So  that  in  this  case  (Fig.  175)  there  would 


CHAr.  xvi.l  ASTIGMATISM.  445 


S 


be  au  astigmatism  of  2  1),  and  the  greatest  refraction  would  be 
in  the  vertical  meridian. 

It  is  generally  desirable  to  begin  with  the  arc  placed  in  the  hori- 
zontal meridian.  If  the  axes  of  the  meridians  of 
greatest  and  least  cnrvature  are  obliqne,  then  the 
images  will  not  lie  in  one  line,  and  the  arc  must 
be  turned  until  they  are  on  a  level.  An  index 
which  moves  on  the  circle  <j  (Fig.  173)  gives  the 
position  of  the  axes.  It  will  be  seen  from  the 
above  description  that  the  astigmometer  merely 
registers  the  amount  of  astigmatism,  but  does  not  enable  us  to 
estimate  the  general  refraction  of  the  eye.  Moreover,  it  is  the 
corneal  astigmatism  alone  which  is  determined,  and  it  will  be  found 
in  most  cases  to  differ  only  slightly  from  the  total  astigmatism.  A 
useful  modification  in  the  mires  consists  in  making  them  of  com- 
plementary colours,  for  instance,  one  red  and  the  other  green,  the 
overlapping  portion  then  appears  w^hite  and  is  easily  seen.  Another 
great  advantage  which  these  coloured  mires  possess  is  the  absence 
of  dispersion,  due  to  the  use  of  mono-chromatic  light,  which  renders 
the  appreciation  of  the  contact  of  the  images  much  more  delicate. 
The  latter  is  the  instrument  used  at  the  Victoria  Hospital,  and  it 
facilitates  the  observations  considerably. 

*  Lental  Asticjmatism. — The  astigmatism  of  the  lens  when  at 
rest  is  supposed  to  be  about  0"75  D,  and  contrary  to  the  rule,  and 
it  tends  therefore  to  correct  or  diminish  corneal  astigmatism  with 
the  rule.  This  assumption  is  based  on  the  fact,  that  often,  when 
there  is  no  subjective  astigmatism,  the  astigmometer  shows  a  corneal 
astigmatism  of  0*75  D  with  the  rule,  which  the  lental  astigmatism 
presumably  corrects.  The  theory  also  accounts  for  the  fact  that 
the  astigmometer  over-estimates  the  total  astigmatism  by  0'5  D  or 
0*75  D  when  with  the  rule,  and  under-estimates  it  by  the  same 
amount  when  against  the  rule  ;  because  in  the  latter  instance  the 
lental  astigmatism  must  be  added  to  that  of  the  cornea,  whereas 
in  the  former  case,  it  must  be  deducted  from  it.  This  lental  astig- 
matism may  be  caused  by  the  shape  of  the  lens,  or  by  an  obliquity 
in  its  position.  A  difference  between  the  subjective  or  total  astig- 
matism, and  that  of  the  cornea  as  measured  by  the  astigmometer, 
can  also  be  accounted  for  by  the  fact  that  the  visual  line  does  not 
pass  through  the  centre  of  the  pupil,  and  therefore  the  portion  of 


446  DISEASES   OF    THE   EYE.  [chap.  xvi. 


the  cornea  iiiccisured  by  the  astigmometer  is  not  exactly  the  same 
as  that  wliich  produced  the  retinal  image.  These  discrepancies, 
however,  do  not  detract  materially  from  the  practical  value  of  the 
instrument. 

Disturbances  of  vision  due  to  astigmatism  often  make  their 
appearance  for  the  first  time  at  middle  age  or  even  later,  and  are 
then  apt  to  be  mistaken  for  amblyopia.  In  such  cases  the  cornea 
has  been  astigmatic  all  through  life,  but  the  defect  has  been  masked 
by  a  compensating  astigmatism  of  the  crystalline  lens,  produced, 
it  is  supposed,  by  an  unequal  accommodative  contraction  of  the 
ciliary  muscle.  When,  as  life  advances,  the  amplitude  of  accom- 
modation diminishes,  the  power  of  the  ciliary  muscle  to  produce 
this  active  compensatory  lental  astigmatism  also  diminishes,  and 
finally  disappears,  and  then  the  corneal  astigmatism  becomes  mani- 
fest ;  or,  in  astigmatic  individuals  the  astigmatism  may  alter  in 
degree  at  this  time  of  life.  Astigmatism  '"  against  the  rule  "  is 
more  common  in  old  than  in  young  persons.  Under  atropine,  too 
astigmatism  may  appear,  the  existence  of  which  was  not  previously 
known.     This  is  termed  active,  or  dynamic,  lental  astigmatism. 

Prescription  of  Cylindrical  Lenses. — The  required  position  of  the 
axis  of  a  cylinder  in  a  prescription  is  indicated  by  a  line  at  the 
extremity  of  ^vhich  a  number  indicates  in  degrees  its  inclination 
to  the  vertical  or  horizontal,  e.g.  2  D.  Cyl.  ax.  p^°.  In  sphero- 
cylinders  one  surface  of  the  glass  is  spherical  and  the  other  cylin- 
drical. Since  the  axis  of  cylindrical  lenses  must  occupy  a  definite 
and  unalterable  position  before  the  eyes,  spectacle  frames  or  rigid 
spiral-spring  pince-nez  should  be  ordered,  and  not  folders.  When 
first  worn,  cylindrical  glasses  frequently  appear  to  cause  distortion 
in  tlie  shape  of  objects,  and  unpleasant  sensations  of  giddiness  ; 
these  symptoms,  however,  disappear  Avith  a  little  perseverance  in 
the  use  of  the  glasses. 


o* 


Irregular  Astigmatism. 

In  irregular  astigmatism,  the  refraction  of  the  eye  differs  not 
only  in  different  meridians  of  tlie  eye,  but  even  in  different  parts 
of  one  and  the  same  meridian.  It  is  frequently  due  to  irregularities 
of  the  surface  of  the  cornea,  the  result  of  former  ulcers,  and  also 
sometimes  to  irregular  refracting  power  in  different  parts  of  the 


CHAP.  XVI.]  ANISOMETROPIA.  447 


crystalline  lens.  It  cannot  be  corrected.  Its  presence  can  be  de- 
tected by  a  distortion  and  irregular  movement  of  the  optic  disc 
when  the  lens  is  moved  during  the  indirect  method  of  examining 
with  the  ophthalmoscope,  by  Placido's  disc,  and  also  by  an  irregular 
shadow  in  retinoscopy.  In  some  cases,  there  is  a  certain  amount 
of  regular  astigmatism  combined  with  it,  correction  of  which  may 
improve  the  vision. 

*  Anisometropia.  ^ 

By  this  term  is  meant  a  difference  in  the  refraction  of  the  two 
eyes,  one  being  myopic,  hypermetropic,  or  astigmatic,  while  the  other 
is  emmetropic,  or  ametropic  in  a  way  different  from  its  fellow.  It 
has  been  shown  that  in  these  cases  the  same  amount  of  accommoda- 
tion takes  place  in  both  eyes.  So  long  as  the  difference  in  refraction 
is  but  slight  (say  1  D  or  1*5  D),  it  is  generally  possible  to  give  the 
correcting  glass  to  each  eye.  When  the  difference  is  considerable 
it  is  often  impossible  fully  to  correct  each  eye,  because,  binocular 
vision  having  never  really  existed,  the  patients  are  unable  to  tolerate 
the  presence  of  a  clear  image  on  each  retina.  We  must  then  be 
content  with  correction  of  the  least  ametropic  eye,  or  of  that  one 
which  has  the  best  vision  ;  or,  we  may  partially  correct  the  most 
ametropic,  and  fully  correct  the  least  ametropic  eye.  If  one  eye 
be  emmetropic  no  correction  may  be  necessary.  Each  such  case 
must  be  dealt  with  as  it  permits. 

Estimation  of  the  Refraction  by  Aid  of  the  Ophthal- 
moscope. 

Estimation  of  the  Refraction  by  the  Inverted  Method. — The  position  of 
the  inverted  image,  in  other  words  its  distance  from  the  lens  used,  depends 
on  the  strength  of  the  lens,  its  distance  from  the  eye,  and  on  the  refrac- 
tion of  the  eye.  If  the  number  of  the  lens  and  its  distance  be  fixed,  the 
refraction  alone  causes  the  alteration  in  the  position  of  the  inverted  image. 
In  Em.,  the  emerging  rays  being  parallel,  the  image  is  formed  at  the  focus 
of  the  lens  ;  in  M.,  the  rays  being  convergent,  the  image  is  closer  to  the 
lens  ;  and  in  H,  it  is  farther  away,  owing  to  the  divergence  of  the  rays 
coming  out  of  the  eye.  The  methods  of  measuring  the  refraction  which 
are  based  on  these  principles  have  not,  however,  come  into  general 
practical  use. 

^   d,    priv.  ;     Laos,    like  ;     /Lurpov,    a   measure. 


448 


DISEASES   OF    THE   EYE. 


[chap.    XVI, 


By  the  Direct  Method  at  a  distance  of  about  50  cm.  from  the 
observed  eye  into  which  light  from  the  ophthalmoscope  mirror  is 
thrown,  the  observer  will  be  able  to  make  the  qualitative  diagnosis 
of  the  refraction.     If  he  can  see  some  of  the  details  of  the  fundus, 


the  eye  is  either  myopic  or  hypermetropic  ;  but  if  it  be  emmetropic, 
or  have  M.  of  less  than  2  D,  he  will  be  unable  to  see  any  detail. 
The  explanation  of  this  is  that,  in  myopia,  the  rays,  from  any  one 
point  on  the  retina,  emerging  from  the  eye,  form  an  inverted  image 
at  the  far  point  of  the  eye  in  the  air,  and  this  image  can  be  seen  by 
the  observer  who  accommodates  his  eye  for  that  point.  In  hyper- 
metropia,  the  issuing  rays  being  divergent  pass  into  the  observer's 
eye,  and,  by  an  effort  of  accommodation  on  his  part,  he  will  see  an 
upright  image  of  the  portion  of  the  patient's  fundus  oculi  from  which 
they  come.  But  in  emmetropia,  or  low  degrees  of  ametropia,  in- 
asmuch as  the  rays  come  out  either  parallel  or  very  nearly  so,  those 
from  any  two  points  {m,  n,  Fig.  176)  at  a  short  distance  from  each 


Fio.    177. — Apparent  motion  of  fvindiis  with   tlie  observer  in  H. 

other  in  the  fundus  on  emerging  from  the  eye  diverge  quickly  from 
each  other,  and  the  observer  a  little  way  off  (at  A)  receives  none 
of  them  into  his  eyes,  or  obtains  only  an  indistinct  image  or  red 
glare.     If  he  go  very  close  to  the  eye  he  can  see  details. 


CHAP.  XVI.]    OPHTHALMOSCOPE   AND   REFRACTION.  449 

If,  on  the  observer  moving  his  head  from  side  to  side,  the  vessels, 
etc.,  of  the  observed  fundus  move  with  him,  the  case  is  one  of  hyper- 
metropia,  if  against  him  it  is  a  case  of  myopia.  In  H.  (Fig.  177)  the 
observer  at  0  sees  an  erect  image  of  the  fundus  at  F  behind  the  plane 
of  the  pupil,  P,  and  it  appears  to  be  situated  at  A  ;  on  moving  the 
head  to  0',  the  line  of  vision  is  0  F,  and  F  appears  to  be  at  A'.  In 
myopia  (Fig.  178)  the  image  is  an  inverted  one  lying  in  front  of  the 


Fig.  178, — Apparent  motion  of  fundus  against  the  observer  in  M. 

plane  of  the  pupil  at  F,  and  when  the  observer  changes  to  0'  the 
image  appears  to  be  in  the  pupil  at  A'. 

*  For  the  quantitative  determination  of  ametropia  a  refraction 
ophthalmoscope  is  required.  This  instrument  is  provided  with  a 
number  of  convex  and  concave  lenses  capable  of  being  brought  into 
position  behind  the  sight-hole  in  rapid  succession  by  a  simple 
mechanism  ;  and  also  with  a  tilted  mirror  which  avoids  the  necessity 
of  holding  the  ophthalmoscope  in  an  oblique  position,  and  thus  the 
lenses  are  maintained  in  a  position  at  right  angles  to  the  visual 
axis  of  the  observer.  The  direct  method,  close  up  to  the  patient's 
eye,  is  employed. 

It  is  necessary,  in  the  first  instance,  that  the  observer  be  acquainted 
with  the  nature  of  his  own  refraction. 

*  //  the  Observer  he  Eminetropic  he  can  see  the  fundus  oculi  of  an 
emme trope  in  the  upright  image  without  any  lens,  provided  he  go 
close  enough,  as  the  parallel  rays  coming  from  the  examined  eye 
will  be  focussed  on  his  retina,  because  his  eye  is  adapted  for  parallel 
rays. 

In  order  to  see  the  fundus  oculi  of  a  hypermetrope  without  any 
effort  of  accommodation,  he  must  place  such  a  convex  lens  behind 
his  ophthalmoscope  as  will  render  the  divergent  rays  coming  from 
the  patient's  eye  parallel  before  they  pass  into  his  eye.  This  lens  is 
the  measure  of  the  patient's  hypermetropia,  because  it  shows  how 
many  dioptres  the  eye  wants  of  being  emmetropic.  The  lens  which 
29 


450  DISEASES    OF    THE   EYE.  [chap.  xvi. 


makes  the  divergent  rays  coming  from  the  patient's  retina  parallel, 
would  also  give  to  parallel  rays  passing  into  the  eye  such  convergence 
that  they  would  meet  on  the  retina — i.e.  it  would  correct  the  hyper- 
metropia  if  the  patient  were  examined  with  test-types  and  glasses 
(p.  431.)     (See  Fig.  162.) 

The  emmetropic  observer  can  of  course  see  the  fundus  oculi  of  a 
hypermetrope  by  the  direct  method  without  the  correcting  glass,  if 
he  use  his  accommodation  to  overcome  the  divergence  of  the  rays 
coming  from  the  observed  eye,  and  this  is  usually  the  case  in  the 
lower  degrees  of  hypermetropia.  The  observer  generally  relaxes 
his  accommodation  according  as  he  substitutes  convex  lenses  for  it, 
until  he  reaches  the  strongest  lens  with  which  he  can  distinctly  see 
the  fundus.     This  is  the  correcting  lens. 

To  see  the  fundus  oculi  of  a  myope,  the  emmetropic  observer 
must  place  a  concave  glass  behind  his  ophthalmoscope,  in  order  that 
the  convergent  rays  coming  from  the  observed  eye  may  be  made 
parallel  before  they  pass  into  his  eye ;  and  the  lowest  concave  lens 
which  enables  him  to  see  the  fundus  oculi  distinctly  is  the  measure 
of  the  myopia  (p.  418),  as  showing  by  how  many  dioptres  it  is  in 
excess  of  emmetropia. 

The  emmetropic  observer  cannot  possibly  see  the  fundus  oculi 
of  a  myope  without  the  correcting  glass,  as  the  rays  are  brought  to 
a  focus  in  front  of  his  retina,  and  if  he  use  his  accommodation  he 
merely  makes  them  still  more  convergent.  But,  by  means  of  an 
effort  of  his  accommodation  he  can  see  the  myopic  fundus  with  a  lens 
which  over-corrects  the  myopia,  and  hence  the  importance  of 
selecting  the  weakest  concave  glass  with  which  the  fundus  is  distinctly 
seen. 

If  the  observer  be  ametropic,  he  may  either  correct  his  ametropia 
by  wearing  the  suitable  lens,  and  then  proceed  as  though  he  were 
emmetropic,  or  else,  and  which  is  perhaps  the  better  plan,  he  must 
allow  for  the  amount  of  his  ametropia. 

For  example  : — 

*  The  Hypermetropic  Observer  of  say  3  D  requires  a  -f  lens  of  3  D 
in  order  to  see  an  emmetropic  fundus  oculi,  this  lens  going  altogether 
to  correct  his  own  defect.  If  in  order  to  examine  the  fundus  of 
another  eye  he  require  a  -j-  lens  of  6  D,  the  examined  eye  must  be 
hypermetropic  3  D,  the  other  3  D  going  to  correct  the  observer's 
H.     If  he  be  able  to  see  the  fundus  oculi  under  observation  without 


TftAP.  xvr.]        OPHTHALMOSCOPE   AND    RKFR ACTION.  45J 


any  lens,  it  shows  that  the  eye  has  an  excess  of  refraction  correspond- 
ing with  the  want  of  refraction  in  his  own  eye — that  is  to  say,  it  is 
myopic  3D.  If  he  require  a  concave  2  D,  his  want  of  refraction — 
his  hypermetropia — is  not  enough  by  that  number  of  dioptres,  and 
he  has  to  do  with  an  eye  which  is  myopic  5  D  (3  D  +  2  D).  Again, 
if  he  can  see  the  fundus  distinctly  with  a  +  lens,  say  +  1  D,  which 
is  less  than  his  own  correcting  glass,  this  shows  that  the  eye  he  is 
examining  is  myopic,  but  myopic  to  a  lesser  degree — in  this  instance 
by  1  D — than  he  himself  is  hypermetropic,  and  the  examined  eye 
here  would  be  M.  2*0  D  {i.e.  S'O-l-O). 

If  the  Observer  be  myopic  the  same  method  of  reasoning  applies. 

*  The  Existence  and  Degree  of  Astigmatism  7nay  be  Determined 
mth  the  Ophthalmoscope. — We  know  that  astigmatism  is  present,  if 
in  the  upright  image  we  see  the  upper  and  lower  margins  of  the  disc 
and  the  horizontal  vessels  well  defined,  while  the  lateral  margins 
and  the  vertical  vessels  are  blurred,  or  vice  versa.  Again,  we  know 
that  astigmatism  is  present  if,  in  comparing  the  shape  of  the  optic 
disc  in  the  upright  and  inverted  images,  we  find  it  to  be  an  oval 
with  its  long  axis  perpendicular  in  the  former,  and  with  its  long  axis 
horizontal  in  the  latter,  showing  that  the  refracting  media  are  more 
powerful  in  the  vertical  than  in  the  horizontal  meridian. 

We  may  ascertain  the  kind  and  degree  of  astigmatism  as 
follows  : — 

If  in  the  upright  image  with  relaxed  accommodation,  we  can  see 
the  retinal  vessels  in  one  meridian  distinctly,  while  in  order  to  see 
those  in  the  opposite  meridian  a  concave  or  convex  lens  behind  the 
ophthalmoscope  is  required,  we  know  that  the  case  is  one  of  simple 
myopic  or  hypermetropic  astigmatism  ;  the  emmetropic  meridian 
being  that  at  right  angles  to  the  vessels  ^  seen  without  any  lens,  and 
the  number  of  the  lens  indicating  the  amount  of  ametropia  in  the 
other  meridian. 

If,  in  the  two  principal  meridians,  two  concave  lenses  or  two 
convex  lenses  of  different  strength  be  required,  we  have  to  deal  with 
a  case  of  compound  astigmatism,  myopic  or  hypermetropic  ;  the 
greatest  error  of  refraction  being  in  the  meridian  at  right  angles  to 
that  one,  the  vessels  of  which  are  made  distinct  by  the  strongest  lens. 

^  The  vessels  may  be  regarded  as  lines,  and  the  explanation  given  on 
p.  434  applies  to  them  also. 


452  DISEASES    OF    THE   EYE.  [ohap.  xvi. 


If  a  concave  lens  be  required  to  bring  into  distinct  view  the 
vessels  in  one  meridian,  while  a  convex  lens  is  required  for  the 
opposite  meridian,  tlic  case  is  one  of  mixed  astigmatism.  Myopia 
exists  in  the  meridian  at  right  angles  to  that  in  which  the  vessels 
are  brought  into  view  by  the  concave  lens,  and  hypermetropia  exists 
in  the  opposite  meridian. 

Retixoscopy. 

Eetinoscopy,  or  the  Shadow  Test,  is  the  most  useful  method  for 
determining  the  refraction  by  the  ophthalmoscope.  It  consists  in 
illuminating  the  eye  with  the  plane  or  concave  mirror  at  a  distance 


Fig.   179. — Motion  of  the  virtual  image  in  rotation 
of  a  plane  mirror. 

of  a  little  over  a  metre,  or  more,  and  then  moving  the  light  into 
different  positions  by  rotation  of  the  mirror  round  an  axis  lying  in 
its  own  plane,  the  observer  noting  on  which  side  of  the  illuminated 
pupil  the  shadow  appears,  and  in  which  direction  it  moves  across 
the  pupil. 

Direction  of  Displacement  of  the  Image  when  a  Mirror  is  rotated  round 
an  Axis  lying  in  the  Plane  of  the  Mirror. — Wlien  a  plane  mirror  is  rotated, 
the  image  of  the  source  of  light  moves  in  a  direction  opposite  to  that 
in  which  the  mirror  is  rotated.  In  Fig.  179  when  the  mirror  is  rotated 
from  Ml  to  M2  the  image  of  the  light,  L,  will  be  found  on  the  per- 
pendiculars to  the  mirror,  j\Ii  and  Mj,  at  Ii,  and  lo.  The  cones  of  rays 
emerging  from  these  images,  ai  ui  and  62  bz,  will  move  with  the  rotation 
of  the  mirror  as  indicated  by  arrow  B,  while  the  images  have  moved  in 
the  opposite  direction,  shown  by  arrow  A.  When  a  concave  mirror  is 
rotated,  the  image  moves  in  the  same  direction  as  the  mirror.  In  Fig.  180 
when  the  mirror  is  in  the  position  M^,  the  image  of  L  is  formed  at  I^,  on 


CHAP.    XVI.] 


RETINOSCOPY. 


453 


the  secondary  axis  passing  through  the  centre  of  curvature  C^  ;  and,  on 
rotating  the  mirror  into  the  position  M^,  the  corresponding  image  will  be 
found  on  the  secondary  axis  L  C^,  say  at  T-,  the  change  of  position   of 


Fig.  180. 


-Motion  of  inverted  iinage  in  rotation 
of   a  concave   mirror. 


the  image  being  in  the  direction  of  the  arrow,  and  with  the  movement  of 
the  mirror. 

Theory  of  Retinoscopy. — In  the  explanation  which  follows,  the  con- 
cave mirror  is  supposed  to  be  used.  In  Fig.  181,  rays  from  the  light,  O, 
placed  at  the  side  of  the  patient's  head,  strike  the  mirror,  A,  which  forms 
an  inverted  aerial  image.  A',  as  explained  in  chap.  ii.  This  image  is  now 
the  immediate  source  of  light,  rays  from  which,  entering  the  eye,  are  made 


Fig.  181. — Retinoscopy  with  concave  mirror.  Shows  that  the  real 
movement  of  the  retinal  image  is  the  same  in  all  conditions  of  refraction. 
1.  Motion  of  mirror,  or  of  light  area  on  patient's  face.  2.  Motion  of 
aerial  image  produced  by  mirror  (immediate  source  of  light).  3.  Real 
motion  of  retinal  image  of  light. 


to  converge  toward  their  conjugate  focus,  /,  on  the  secondary  axis,  A'  N  /, 
passing  through  the  nodal  point,  N.  If  the  retina  be  at  M',  or  in  other 
words,  if  the  eye  be  myopic,  with  its  far  point  at  A',  a  distinct  and  bright 
image  of  the  light  A,  will  be  formed  on  the  retina  at  /.     In  any  other 


454  DISEASES   OF   THE   EYE.  [chap.  xvi. 

condition  of  refraction  such  as  emmetropia,  E.,  hypermetropia,  H.,  or 
any  higher  degree  of  myopia,  M.,  a  circle  of  diffusion,  c  d,  is  formed  by  each 
point  of  light,  and  a  blurred  image  is  the  result ;  so  that  the  area  of  illu- 
mination is  less  bright,  and  its  bovindary  less  defined.  The  farther  the 
retina  is  from  /,  the  less  will  be  the  brightness  and  the  definition  of  the 
margin  of  the  illuminated  area. 

Now  let  the  mirror  be  rotated  from  A  to  B,  the  movement  of  the  light 
area,  surrounding  the  eye,  on  the  patient's  face  will,  of  course,  take  the 
same  direction,  indicated  by  the  arrow  I.  As  explained  at  the  beginning 
of  this  chapter,  the  immediate  source  of  light  will  move  to  B',  shown  by 
arrow  2,  and  its  image  will  be  formed,  more  or  less  distinctly,  on  the  re- 
tina, at  the  point  at  which  it  is  intersected  by  the  secondary  axis  B'  N  6. 
The  retinal  image,  therefore,  will  move  in  the  direction  of  arrow  3,  from 
a  to  6,  and  this  motion,  as  the  figure  shows,  is  the  same  in  all  positions 
of  the  retina.  The  real  motion  of  the  retinal  image  of  the  light  in  the 
observed  eye  is  therefore  independent  of  the  refraction  of  the  eye,  and 
is  in  a  direction  contrary  to  that  of  the  immediate  source  of  light,  and  also 
against  the  motion  of  the  concave  mirror. 

The  observer  cannot,  however,  see  directly  what  is  taking  place  on 
the  retina  of  the  observed  eye,  since  he  can  only  examine  it  through  its 
refractive  media.  It  remains,  therefore,  to  determine  the  effect  of  tho 
refraction  of  the  observed  eye  on  the  motion  as  it  appears  to  the  observer ; 
tliis  may  be  called  the  apparent  movement.  What  the  observer  sees  is 
the  image,  real  or  virtual,  formed  by  the  observed  eye,  at  its  conjugate 
focus  or  far  point,  and  therefore  the  apparent  movement  will  depend  on 
the  position  of  the  far  point. 


Fig.  182. — Retinoscopy,  with  concave  mirror,  in  hypriin'>tropia.  1. 
Motion  of  mirror.  2.  Motion  of  immediate  source  of  light.  3.  Real 
motion  of  retinal  image.     4.  Apparent  motion  of  retinal  image. 

In  H  (Fig.  182)  the  immediate  source  of  light,  A,  illuminates  a  portion 
of  the  retina  at  a.  The  rays  e,  f  emerging  from  this  point  diverge,  and 
entering  the  observer's  eye  seem  to  him  to  come  from  a,  the  far  point 
of  the  hypermetropic  eye.  When,  by  reason  of  a  rotation  of  the  mirror 
to  B,  the  light  moves  to  B',  its  retinal  image  6,  seems  to  be  at  /3.  The 
illuminated  area  seems  therefore  to  have  moved  in  the  direction  of  arrow 
4 — that  is,  (Kjdlnst  \\w  mot  ion  of  the  mirror  (arrow  1). 


CHAP.    XVI.] 


RETINOSCOPY. 


455 


In  Em.  similarly,  the  emergent  rays  are  parallel,  and  the  image  is 
projected  by  the  observer  to  a  position  behind  the  eye  under  examination. 
Stated  simply,  in  both  cases  an  erect  image  of  the  fundus  is  seen,  there- 
fore no  reversal  of  the  rays  takes  place  between  the  eye  of  the  observer 
and  that  of  the  person  under  observation  ;  and  consequently,  the  apparent 
motion  is  the  same  as  the  real.  As  the  light  moves  from  a  to  &  and  so 
passes  on,  the  pupil  will  first  appear  to  become  darkened  above,  and  the 
shadow  will  move  across  it  as  shown  in  the  circle  P. 


Fig.    1 83. — Retinoscopy    with   concave   mirror   in  Myopia.     Numbers   as 

in  Fig.   182. 


In  Myopia,  on  the  other  hand  (Fig.  183),  the  rays  from  the  illuminated 
area  a  converge  to  form  an  inverted  image  at  a,  the  far  point  of  the  eye, 
situated  on  the  secondary  axis  A'Na.  When  the  immediate  source  of 
light  moves  from  A'  to  B',  the  apparent  movement  is  from  a  to  /3.  In 
this  case  a  reversal  of  the  relative  position  of  the  rays  takes  place,  before 
they  enter  the  observer's  eye  ;  the  upper  rays  become  the  lower  and 
vice  versa.  Hence  this  is  sometimes  called  the  point  of  reversal.  In  this 
case  the  darkness  will  appear  first  at  the  lower  edge  of  the  pupil,  and  will 
travel  upwards  as  indicated  in  the  circle  P,  that  is  to  say,  in  the  same 
direction  as  arrow  1,  with  the  movement  of  the  concave  mirror. 

The  above  explanation  only  holds  good  in  myopia,  when,  as  in  the 
figure,  the  far  point  of  the  eye  under  observation  lies  in  front  of  the  ob- 
server's eye.  If,  however,  the  far  point  be  situated  farther  back  than  the 
observer's  eye,  the  rays  will  not  have  met  to  form  the  inverted  image, 
but  will  enter  his  eye  retaining  the  relative  positions  which  they  bore 
to  each  other  on  emerging  from  the  eye  under  observation  ;  consequently, 
the  observer  will  see  an  erect  image  of  the  illuminated  area,  and  the  move- 
ment will  be  as  in  H.  and  Em.,  namely,  against  the  concave  mirror.  It 
is  obvious,  that  the  lower  the  degree  of  myopia  the  farther  away  the 
observer  must  be  in  order  that  he  may  see  the  reversal  of  the  movement. 

An  error  of  refraction  in  the  observer's  eye  does  not  influence  the 
apparent  movement,  but  merely  renders  the  appearance  more  or  less 
distinct  to  him.  It  should  also  be  stated,  that  as  the  observer  accom- 
modates for  the  patient's  pupil,  and  not  for  the  far  point  of  the  retina 
of  the  patient,  the  image  seen  is  always  more  or  less  diffuse. 

Retinoscojyy  ivith  the  plane  fnirror. — The  immediate  source  of  light 
in  the  case  of  a  plane  mirror  is  a  virtual  upright  image  behind  the  mirror 


456  DISEASES   OF    THE   EYE.  [chap.  xvi. 

(Fig.  179).  It  moves  in  the  opposite  direction  to  the  motion  of  the  mirror, 
and  not  with  it,  as  in  the  case  of  the  concave  mirror.  Hence  the  real 
movement  of  the  retinal  image  in  the  patient's  eye  will  be  with  the  mirror. 
The  apparent  movement  will,  therefore,  be  the  same  ;  that  is,  with  the 
mirror,  in  Em,,  H.,  and  in  low  M.,  where  the  point  of  reversal  is  farther 
away  than  the  observer.  In  higher  degrees  of  M.,  with  the  point  of 
reversal  nearer  than  the  observer,  the  real  motion  will  be  reversed,  and 
hence  the  apparent  motion  will  be  against  the  motion  of  the  mirror. 

Degree  of  illumination,  form,  and  rate  of  movement  of  the  shadow. — As 
showai  in  Fig.  181,  when  the  retina  is  at  the  conjugate  focus  of  the  immedi- 
ate source  of  light,  the  iUumination  is  at  its  greatest.  The  farther  away 
the  retina  is  from  the  conjugate  focus,  that  is  to  say,  the  higher  the  H. 
or  M.,  the  larger  must  be  the  area  over  which  the  light  is  spread,  and 
therefore  the  more  defective  the  illumination  becomes,  and  the  less  defined 
and  the  fainter  is  the  edge  of  the  shadow. 

The  higher  the  error  of  refraction,  the  nearer  to  the  eye  is  the  far  point, 
and  the  smaller  is  the  remote  image  ;  but  with  the  smaller  image  a  larger 
field  is  obtained,  and  more  of  the  circular  edge  of  the  shadow  is  seen  ; 
hence,  the  latter  appears  crescentic.  In  the  lower  degrees  of  ametropia 
and  more  especially  in  Em.,  the  magnification  is  much  greater  and  the 
field  is  smaller.  Therefore,  a  small  portion  only  of  the  large  circular 
edge  is  visible,  causing  the  shadow  to  appear  less  crescentic  and  more 
linear. 

The  apparent  rate  of  movement  depends  more  on  the  degree  of  magni- 
fication of  the  remote  image,  than  on  the  real  rate  of  movement  of  the 
retinal  image.  The  less  the  magnification  the  slower  the  movement 
appears,  for  instance  in  Figs.  182  and  183,  if  the  far  point  were  in  each  case 
at  c,  the  light  would  have  to  travel  only  from  d  to  c,  instead  of  from"  a  to 
^,  with  the  same  rotation  of  the  mirror.  At  c,  therefore,  it  would  appear 
to  travel  a  shoioer  distance  in  the  same  time,  and  would  therefore  appear 
to  move  slower.  The  higher  the  ametropia,  then,  the  slower  appears  to 
be  the  movement  of  the  shadow. 

Practice  of  Retinoscopy  with  the  Concave  Mirror.— The  examina- 
tion is  conducted  in  the  dark  room.  The  light  is  placed  at  the  side 
of,  or  above  the  patient's  head,  and  behind  the  level  of  his  eye,  so 
that  the  latter  may  be  in  the  shadow.  If  the  concave  mirror  be 
used,  the  observer  sits  at  a  distance  of  r25  m.  in  front  of  the  patient. 
The  focal  length  of  the  mirror  should  be  about  22  cm.,  and  the 
diameter  of  the  sight-hole  about  3  mm.  The  observer  should  correct 
any  error  in  his  refraction.  The  light  is  then  thrown  into  the 
patient's  eye,  near  the  region  of  the  macula  lutea,  but  not  on  it, 
unless  the  pupil  be  dilated  by  atropine,  otherwise  the  pupil  becomes 
too  small  and  the  red  reflex  too  faint.  The  observer  accommodates 
for  the  pupil,  and  rotating  the  ophthalmoscope,  usually  in  the  hori- 
zontal and  vertical  meridians,  he  observes    the  shadow  at  the  cir- 


CHAP.  XVI.]  RETINOSCOPY.  457 

cumference  of  the  pupil.  When  the  mirror  is  rotated — say,  in  the 
horizontal  meridian — the  edge  of  the  shadow  will  be  vertical,  it 
will  move  horizontally,  that  is  at  right  angles  to  its  edge,  and  it 
will  indicate  the  refraction  of  the  horizontal  meridian.  If  the  move- 
ment of  the  shadow  be  with  the  movement  of  the  mirror,  or  with 
the  light  on  the  patient's  face,  myopia  is  present ;  if  it  move  against 
the  mirror,  Em.,  H.,  or  M.  of  less  than  1  D  is  present. 

The  reason  why  the  shadow  is  against  the  mirror  in  cases  of 
less  than  1  D  is  that,  in  M.  of  1  D,  the  inverted  image  or  point  of 
reversal  of  the  emerging  rays  is  situated  at  the  far  point  of  the 
patient's  eye,  namely  1  m.  in  front  of  the  patient,  and  the  observer 
being  25  cm.  farther  away  sees  this  inverted  image.  But  if  the 
myopia  be  less  than  1  D,  the  far  point,  or  point  of  reversal,  lies 
behind  the  observer's  head,  and  he  now  sees  an  erect  image  as  in 
Em.  or  H.,  and  the  apparent  movement  is  then  the  same  as  in  Em. 
or  H.,  namely  against  the  mirror. 

In  order  to  estimate  the  error  of  refraction,  a  trial  spectacle- 
frame  is  put  on  the  patient's  face.  If  the  shadow  move  with  the 
mirror,  we  know  at  once  the  eye  is  myopic.  To  find  the  degree  of 
myopia,  the  observer  puts  a  low  concave-glass  (say  —  ID)  into  the 
frame  ;  and  if  the  shadow  still  move  with  the  mirror,  he  puts  in  a 
higher  number  (say  —  1*5  D),  and  so  on  until  he  comes  to  a  glass 
which  makes  the  image  move  against  the  mirror.  If  this  be  —  3D, 
the  myopia  is  3  D.  It  might  be  supposed,  as  the  shadow  now  moves 
against  the  mirror,  that  this  glass  over-corrects  the  myopia  ;  but 
this  is  not  so,  because,  as  already  explained,  when  the  myopia  is 
very  low  the  image  is  formed  close  to  the  observer's  eye,  or  behind 
his  head,  and  he  consequently  gets  a  shadow  moving  against  the 
mirror,  although  low  myopia,  and  not  emmetropia,  is  present.  Con- 
sequently, —  0'5  D,  or  —  ID,  has  to  be  added  on  to  the  lens,  which 
gives  the  effect  of  no  distinct  shadow  ;  or  rather,  by  the  above  plan, 
it  is  not  deducted  from  the  lowest  lens,  which  makes  the  shadow 
move  against  the  mirror. 

If  the  shadow  move  against  the  mirror,  we  have  to  determine 
whether  the  eye  is  emmetropic,  hypermetropic,  or  slightly  myopic. 
Should  the  illumination  be  bright,  and  the  shadow  well  defined, 
the  eye  is  emmetropic,  or  not  far  removed  from  it ;  and  if  the  shadow 
be  ill  defined  and  crescentic,  we  may  feel  sure  the  eye  is  highly 
hypermetropic.     We  first  put  on  -|-  1  D,  and  if  the  motion  be  still 


458 


DISEASES    OF   THE   EYE. 


[chap.    XVI. 


against  the  mirror,  the  case  is  one  of  hypermetropia,  and  higher 
numbers  are  at  once  proceeded  to,  until  that  one  is  reached  which 
causes  the  shadow  to  move  with  the  mirror.  The  measure  of  the 
hypermetropia  is  1  D  less  than  tlie  glass  so  found,  for  it  has  evidently 
over-corrected  the  defect,  having  made  the  eye  1  D  myopic. 

If,  however,  on  putting  on  -f  1  I^  we  find  the  shadow  to  move 
with  the  mirror,  we  change  it  for  -f  ^^'5  D  ;  and  if  still  the  motion 
be  with  the  mirror,  the  eye  is,  beyond  doubt,  slightly  myopic,  —  0*5 
D  or  so.  But  if  with  +  1  D  the  shadow  move  with  the  mirror, 
while  with-f  0'5  it  continue  to  move  against  it,  the  eye  is  emmetropic. 
In  astigmatism,  the  light  being  differently 
focussed  in  two  meridians  at  right  angles  to 
each  other,  and  being  drawn  out  into  a  line 
or  oval  of  diffusion,  causes  the  illuminated 
area  to  appear  like  a  band.  The  boundary 
of  the  shadow  therefore  is  more  of  a  straight 
line  than  a  circle.  If  the  axes  of  the  astig- 
matism be  oblique,  the  edge  of  the  shadow 
will  lie  in  one  of  the  meridians,  and  the 
movement  will  take  place  in  the  other  one — 
according  to  the  direction  of  the  rotation  of 


Fig.  184.— If  the 
ruler  C  D  be  moved 
behind  the  circle  in 
the  direction  of  R, 
its  obHquity  being 
preserved,  it  will  ap- 
pear to  a  person  who 
sees  only  the  portion 
inside  the  circle,  to 
move  in  direction  A. 


the  mirror.  Even  if  the  mirror  be  not 
rotated  in  the  direction  of  the  meridian  of 
greatest  or  least  refraction,  the  edge  of  the 
shadow  will  nevertheless  lie  in  the  direction 
of  one  of  these  meridians,  namely  in  that 
which  is  nearest  to  the  axis  of  rotation,  and 
will  appear  to  move  in  the  meridian  at  right  angles  to  it.  This  is 
due  to  an  optical  illusion  explained  by  Fig.  184. 

It  may  be  found  that  in  opposite  meridians  there  is  a  difference 
in  the  motion  of  the  shadow,  and  this  indicates  the  presence  of 
astigmatism.  When  the  difference  is  one  merely  of  rapidity  of 
motion,  or  of  intensity  of  illumination  and  shadow,  it  is  either 
simple  hypermetropic  or  compound  astigmatism.  But  if  in  the  two 
meridians  there  be  a  difference  in  the  direction  of  the  motion,  then 
it  is  either  simple  myopic  or  mixed  astigmatism. 

In  some  rare  cases  the  refraction  is  different  at  opposite  sides 
of  the  pupil,  and  a  double  shadow  is  seen.  These  shadows  move 
simultaneously   in  o})posite   directions  ;     that   is.   towards  or  away 


CHAP.  XVI.  1  RETINOSCOPY.  459 


from  each  other,  like  the  blades  of  scissors,  and  hence  the  condition 
is  known  as  "  scissors  movement."  In  conical  cornea,  an  irregular 
or  triangular  shadow  is  seen,  with  its  apex  near  the  centre  of  the 
pupil ;  it  rotates  round  its  apex  with  the  movements  of  the  mirror. 
In  irregular  astigmatism,  the  shadow  appears  broken  up  very  irregu- 
larly, and  different  portions  of  it  move  in  various  directions. 

In  retinoscopy  the  best  method  of  ascertaining  the  degree  of 
astigmatism  and  its  correcting  glass  is  to  correct  each  of  the  prin- 
cipal meridians  separately  with  spherical  lenses.  In  compound 
astigmatism,  the  difference  between  the  two  lenses  found  indicates 
the  degree  of  astigmatism,  and  also  the  cylindrical  lens  which,  com- 
bined with  the  correcting  spherical  lens  for  the  least  ametropic 
meridian,  is  required  to  neutralise  the  defect.  In  mixed  astigma- 
tism, the  addition  of  the  two  numbers  gives  the  cylindrical  lens, 
while  one  or  other  of  them,  usually  the  — D,  is  used  as  the  spherical 
lens. 

Retinoscopy  with  the  plane  mirror. — As  explained  on  p.  452, 
the  immediate  source  of  light  moves  in  a  direction  the  reverse  of 
that  which  is  produced  by  the  concave  mirror  ;  therefore,  the  appar- 
ent movement  is  ivith  the  mirror  in  H.,  Em.,  or  low  M.,  and  against 
it  in  the  other  degrees  of  M.  It  will  be  noticed  that  this  is  the  same 
as  the  apparent  movement  of  the  vessels  when  the  observer  moves 
his  head  (p.  449).  The  advantage  of  the  plane  mirror  is,  that  the 
observer  can  stand  farther  away  from  the  patient,  and  thus  diminish 
the  ertor  of  observation.  If,  for  example,  the  distance  be  a  little 
more  than  4  m.  when  the  shadow  moves  with  the  mirror,  the  ob- 
server know^s,  if  M.  be  present,  it  must  be  less  than  0*25  D.  He 
has  still  to  decide  whether  this  indicates  E.  or  H.  He  does  so  by 
putting  a  low  +  lens  (say  +  0*25)  before  the  patient's  eye,  and  if 
then,  standing  at  a  distance  of  4  metres,  the  motion  be  altered  by 
this  glass  to  one  against  the  mirror,  he  knows  that  the  eye  has 
not  a  hypermetropia  of  0*25  D,  consequently  that  it  is  emmetropic. 
But  if  this  lens  does  not  at  that  distance  cause  a  change  in  the  motion 
of  the  shadow  as  originally  obtained,  the  eye  must  be  hypermetropic 
to  at  least  the  extent  of  0'25  D  ;  and,  in  order  to  ascertain  how  much 
more  of  H.  than  this  may  be  present,  it  is  now  only  necessary  to 
continue  increasing  the  strength  of  the  lens  in  front  of  the  patient's 
eye,  until  one  is  reached  which,  at  4  metres  from  the  eye,  produces 
the  myupic  motion.     The  observer  knows  that  he  has  now  slightly 


460 


DISEASES   OF   THE  EYE. 


[chap.    XVI. 


over-corrected  the  hypermetropia  of  the  eye,  and  that  the  next 
lens  lower  is  its  measure. 

A  plane  mirror  of  4  cm.  diameter,  and  of  which  the  sight-hole 
is  4  mm.  in  diameter,  is  the  pleasantest  to  use  for  retinoscopy. 


ANOMALIES   OF   ACCOMMODATION. 

Presbyopia. 

This  is  a  diminution  in  the  amplitude  of  accommodation  (p.  6), 
which  commences  at  an  early  age,  and  is  due  to  natural  changes 


^.r     .w     ,?r 


4^    .frj     rir 


e.f     m     7J 


Fig.   185. 

taking  place  slowly  in  the  crystalline  lens.  It  might  not,  therefore, 
strictly  speaking,  be  regarded  as  an  anomaly.  The  power  of  ac- 
commodation commences  to  diminish  in  early  childhood,  the  near 
point  beginning  then  to  recede  from  the  eye.  The  accompanying 
diagram  of  Bonders  (Fig.  185),  illustrates  the  decrease  from  the 
tenth  year  of  age,  and  indicates  the  amplitude  of  accommodation 
at  different  ages. 

The  numbers  at  the  top  indicate  the  ages  in  years,  those  on  the 
left  the  amplitude  of  accommodation  in  dioptres.      The  curve  r  r 


CHAP.  XVI.]       ANOMALIES   OF  ACCOMMODATION.  461 

shows  the  refraction  of  the  eye  when  in  a  state  of  rest.  This  is 
unchanged  until  the  fifty-fifth  year,  when  it  begins  to  diminish  ;  the 
emmetropic  eye  then  becoming  hypermetropic,  the  hypermetropic 
eye  more  hypermetropic,  and  the  myopic  eye  less  myopic.  The 
curve  p  p  shows  the  positive  refracting  power  of  the  eye,  corre- 
sponding with  the  punctum  proximum,  and  its  gradual  diminution 
as  life  advances,  and  how  at  the  age  of  65  it  becomes  even  less  than 
the  minimum  refraction  in  former  years.  The  two  curves  meet 
at  the  age  of  73,  and  then  all  power  of  accommodation  ceases.  The 
number  of  dioptres  included  between  the  two  curves  on  the  vertical 
line  corresponding  with  any  given  age  represent  the  amplitude  of 
accommodation  at  that  age — e.g.  at  30  years  of  age  the  amplitude 
is  7  D  ;  at  50  years  it  is  only  2*5  D.  The  amplitude  of  accommoda- 
tion is  the  same  at  the  same  age  in  all  forms  of  ametropia,  as  well  as 
in  emmetropia. 

The  cause  of  presbyopia  lies  chiefly  in  a  progressive  change  in 
the  crystalline  lens,  which  becomes  less  elastic  and  more  homo- 
geneous in  its  different  layers,  and  refracts  light  less  strongly  than 
before.  In  more  advanced  life,  diminished  energy  of  the  ciliary 
muscle  probably  becomes  a  second  factor  in  the  production  of 
presbyopia. 

The  near  point  gradually  recedes  from  the  eye  until  it  reaches 
a  distance  beyond  that  at  which  the  person  usually  reads,  writes, 
sews,  etc.  Employments  of  this  kind  then  become  difficult,  because 
the  retinal  images  are  too  small  to  be  clearly  discerned,  owing  to  the 
increased  distance  at  which  the  work  must  be  held  from  the  eye  ; 
and,  in  order  to  make  up  for  this  smallness  of  the  images,  the  in- 
dividual is  often  seen  to  improve  their  brilliancy  by  procuring 
stronger  light. 

Presbyopia  [TrpeajSvs,  an  old  man  ;  wi/^)  was  defined  by  Donders 
to  be  present  when  the  near  point  lies  at  more  than  22  cm.  from  the 
eye,  and  we  correct  it  by  giving  such  a  convex  glass  for  reading,  etc., 
as  will  bring  the  near  point  back  to  22  cm.  Now  in  order  to  focus 
an  emmetropic  eye  for  that  distance  a  positive  refracting  power 
{p)  of  (-Y/-  =  )  4'5  D  is  necessary,  and  if  the  eye  have  not  so  much 
accommodation,  a  convex  glass  must  be  given  to  it  of  such  power 
as  will  bring  p  up  to  4*5  D  ;  and  this  lens  is  the  measure  of  the  pres- 
byopia. At  the  age  of  40  {vide  Donders'  diagram.  Fig.  185)  the  eye 
possesses  a  positive  refraction  of  just  4*5  D  ;   and  therefore  from  this 


462  DISEASES   OF    THE   EYE.  [chap.  xvi. 


age  presbyopia  is  said  to  commence  in  emmetropic  eyes.  The 
presbyopia,  then,  is  equal  to  the  difference  between  the  accommo- 
dative power  possessed  by  the  eye  and  4'5  D,  and  the  number  thus 
found  is  the  correcting  glass  for  the  presbyopia.  The  distance  of 
22  cm.  is  rather  close  to  the  eyes  for  the  comfort  of  most  people, 
and  33  cm.  is  more  commonly  taken  as  the  reading  distance.  Pres- 
byopia on  the  latter  assumption  is  postponed  for  two  or  three  years. 

The  glass  required  in  presbyopia  must  also  depend  on  the  nature 
of  the  patient's  work,  which,  of  course,  may  require  to  be  placed  at 
some  definite  distance.  This  distance,  the  refraction  of  the  eye,  and 
the  amplitude  of  accommodation  (age  of  the  patient),  will  determine 
the  number  of  the  glass  which  must  be  prescribed  in  each  case. 

It  is  important  that  in  prescribing  glasses  for  presbyopia,  if  there 
be  any  hypermetropic  astigmatism  present,  it  should  be  corrected 
by  the  suitable  +  cylinder  lens  added  to  the  spherical  glasses.  It 
is  also  important  that  the  glasses  should  be  carefully  centred  for  the 
reading  distance — i.e.  that  the  visual  lines,  when  they  are  converged 
to  the  distance  at  which  the  work  is  held,  should  pass  through  the 
optical  centres  of  the  glasses.  The  glasses  must  therefore  be  closer 
together  than  distance  glasses,  and  also  tilted  forwards  at  the  top, 
so  that  they  may  be  at  right  angles  to  the  visual  axes.  Moreover, 
if  there  be  any  insufficiency  of  the  internal  recti,  it  will  be  for  the 
patient's  comfort  to  decentre  the  lenses  slightly  inwards. 

The  following  table  indicates  the  presbyopia  of  the  emmetropic 
eye  : — 


Age. 

p.  required. 

p.  existing. 

Presbyopia. 

40 

4-5 

4-5 

0 

45 

4-5 

3-5 

ro 

50 

4-5 

2  5 

2-0 

55 

45 

1-5 

3-0 

60 

4-5 

0-5 

40 

65 

4-5 

0-25 

4-25 

70 

4a 

-ro 

55 

75 

4-5 

-1-75 

6-25 

80 

45 

-2-5 

7-0 

It  is  hardly  necessary  to  point  out  that  presbyopia  comes  on  at 
a  much  earlier  age  in  hypermetropes  than  in  emmetropes  ;    while  in 
myopes  its  advent  is  postponed  ;  or,  in  the  higher  degrees  of  myopir 
it  may  not  come  on  at  all.     The  hypermetrope  of  3  D  would  be 
presbyopic  at  the  age  of  27  ;   because,  in  order  to  arrive  at  the  4*5  D 


CHAP.   XVI.]        ANOMALIES   OF   ACCOMMODATION.  403 

of  positive  refraction  required,  he  must  have  an  amplitude  of 
accommodation  of  (3  D  -f  "^'^  D)  7 "5  D,  and  this  he  has  up  to 
that  age  only  (Fig.  185). 

The  myope  of  4"5  D  can  get  along  until  something  over  60  years 
of  age  without  any  glass  for  reading  {vide  above  table).  At  65,  if  he 
were  emmetropic,  he  would  have  presbyopia  of  4*25  ;  consequently 
he  will  now  require  a  -|-  glass  of  only  0"25  D. 

Persons  who  have  worn  full  myopic  correction  constantly  need 
to  have  the  power  reduced  for  reading  at  the  presbyopic  age. 

Presbyopia  must  not  be  mistaken  for  slight  paralysis  of  accom- 
modation. They  are  distinguished  by  the  fact  that  in  the  former 
the  amplitude  of  accommodation  corresponds  with  the  age  of  the 
patient  as  given  in  Bonders'  table,  and  the  difficulty  of  near  vision 
comes  on  gradually. 

When  presbyopia  is  associated  with  ametropia,  which  requires 
correction  for  distance,  bifocal  lewises  are  very  convenient.  A  thin, 
oval  or  circular,  lens  (called  a  paster)  representing  the  addition  re- 
quired for  near  vision  is  ground,  or  cemented  on  to  the  lower  part 
of  the  distance  glass,  or  is  inserted  between  the  two  portions  of 
which  this  is  formed.  The  size  of  the  reading  portion  should  be 
about  12  mm.  broad,  by  8  mm.  high,  and  its  upper  border  should 
be  a  few  millimetres  below  the  optical  centre  of  the  distance  lens. 


Paralysis  of  Accommodation  (Cyclopegia). 

This  may  be  partial  or  complete,  and  one  or  both  eyes  may  be 
affected.  It  is  usually  combined  with  paralysis  of  the  sphincter 
iridis  (mydriasis),  and  the  condition  is  then  called  ophthalmoplegia 
interna  ;  but  it  is  also  seen  without  paralysis  of  the  sphincter,  and 
either  alone  or  with  paralysis  of  some  of  the  orbital  muscles  supplied 
by  the  third  pair,  which  also  supplies  the  ciliary  muscle — rarely  with 
paralysis  of  the  external  rectus. 

The  Symptoms  are  similar  to  those  of  presbyopia,  but  they  appear 
rather  suddenly.  They  give  inconvenience  to  the  patient  according 
to  the  state  of  his  refraction.  If  he  be  emmetropic,  his  distant  vision 
continues  good,  while  his  vision  for  near  work  is  much  impeded.  If 
he  be  hypermetropic,  as  he  requires  his  accommodation  for  distant 
objects,  vision  for  distance  is  interfered  with,  and  still  more  so,  vision 


4()4  DISEASES   OF   THE   EYE.  [chap.  xvr. 

for  near  objects.  If  he  be  myopic,  vision  is  less  affected  than  in 
either  of  the  other  forms  of  refraction  ;  indeed,  if  he  have  more  than 
4  D  of  M,  being  thereby  enabled  to  see  near  objects  at  his  far  point, 
he  may  sufl'er  little  or  no  inconvenience. 

Micropsia  is  a  common  symptom  in  cases  of  incomplete  paralysis 
of  accommodation,  and  is  due  to  the  fact  that,  while  the  retinal  image 
is  unaltered  in  size,  the  greater  effort  of  accommodation  required 
gives  the  sensation  of  the  object  being  much  nearer  to  the  eye  than 
it  really  is. 

Causes. — Paralysis  of  accommodation  may  be  caused  by  poisons 
acting  locally  (atropine)  or  through  the  system  (ptomaines,  nicotine, 
lead)  ;  but  it  is  also  the  result  of,  or  is  attendant  upon,  various 
diseases.  It  is  one  of  the  symptoms  of  paralysis  of  the  third  nerve  ; 
it  may  be  due  to  rheumatism  or  to  exposure  to  cold  ;  or  it  may 
depend  upon  syphilis,  syphilitic  periostitis  at  the  sphenoidal  fissure, 
syphilitic  gumma,  or  syphilitic  inflammation  of  the  nerve  itself. 

Double  paralysis  of  accommodation  is  often  nuclear.  Paralysis 
of  accommodation  and  mydriasis  are  sometimes  forerunners  by  many 
years  of  serious  mental  derangement. 

Diphtheria  is  a  frequent  cause  of  paralysis  of  accommodation, 
usually  without,  but  sometimes  with,  mydriasis.  The  onset  occurs 
most  commonly  some  weeks  after  the  throat  affection,  which  need 
not  have  been  of  a  severe  character.  Indeed,  the  faucial  attack 
may  have  had  no  apparent  diphtheritic  character,  and  may  have 
been  so  slight  as  almost  to  have  escaped  the  notice  of  the  patient, 
although  sometimes  albumen  will  be  found  in  the  urine,  the  speech 
may  be  somewhat  nasal  in  character,  and  the  patellar  reflexes  de- 
fective. The  lesion  in  these  cases  is  probably  a  nuclear  one,  and  the 
evidence  points  to  miliary  extravasations  of  blood  in  the  lloor  of 
the  fourth  ventricle  ;  but  some  hold  that  the  paralysis  is  due  to 
a  poison,  that  it  is  a  toxic  paralysis. 

In  influenza,  paralysis  of  accommodation  is  seen,  occurring  some- 
times in  the  acute  stage  and  sometimes  during  convalescence.  One 
recorded  case  went  on  to  bulbar  paralysis,  and  ended  fatally  ;  but 
complete  recovery  is  usual. 

Paralysis  of  accommodation  in  middle  life  may  be  due  to  diabetes, 
and  should  raise  the  suspicion  of  the  presence  of  this  disease.  It 
may  also  occur  in  chronic  alcoholism  and  in  diseases  of  the  spinal 
cord — e.g.  locomotor  ataxy. 


CKAV.   xvi.l       ANOMALIES    OF   ACCOMMODATION.  405 


Blows  on  the  eye  are  apt  to  cause  paralysis  of  accommodation, 
usually  with  mydriasis. 

The  Treatmrnt  depends,  of  course,  upon  the  cause  of  the  paralysis. 
The  instilhition  of  a.  1  per  cent,  solution  of  sulphate  of  eserine  or  of 
muriate  of  pilocarpine  may  be  employed  in  all  cases,  and  will  at 
least  produce  temporary  improvement  of  sight ;  but  it  can  hardly 
be  said  to  assist  in  the  cure,  except  perhaps  in  slight  diphtherial  cases. 
Iodide  of  potassium  and  mercury  are  indicated  in  syphilitic  cases, 
and  iodide  of  pota&sium  and  salicylate  of  sodium  in  rheumatic  cases. 
The  prognosis  in  these  cases  must  be  very  guarded,  as  it  often 
happens  that  recovery  does  not  take  place.  No  further  symptoms 
may  occur,  but  in  some  instances  it  may  be  followed  by  external 
ophthalmoplegia.  Where  cure  does  not  result  the  patient  may  be 
enabled  to  make  better  use  of  his  eye  or  eyes  by  means  of  a  convex 
glass  or  spectacles  ;  but  in  this  matter  each  case  must  be  dealt 
with  for  itself — no  general  rule  can  be  laid  down. 

In  diphtherial  cases  a  general  tonic  treatment,  especially  iron,  is 
indicated  ;    and  here  the  prognosis  is  invariably  favourable. 

Accommodative  Asthenopia 

has  been   already  treated  of    under  the  head  of    Hypermetropia 
(p.  434). 

Spasm  of  Accommodation. 

Spasm,  or  cramp,  of  accommodation  in  connection  with  hyper- 
metropia and  myopia  has  already  been  referred  to.  A  few  cases  of 
acute  spasm  of  accommodation  have  been  reported.  Occurring  in 
an  emmetropic  or  slightly  hypermetropic  eye,  such  a  spasm  produces 
apparent  myopia.  In  some  of  the  cases  there  was  no  assignable 
cause  for  the  spasm,  in  some  it  was  due  to  overwork,  and  in  one  to 
trauma  of  the  cornea.  The  treatment  is  a  lengthened  course  of 
atropine  locally. 


30 


CHAPTER  XVII. 

THE   ORBITAL  MUSCLES  AND   THEIR 
DERANGEMENTS. 

Normal  Action  of  the  Orbital  Muscles. 

The  eyeball,  which  is  held  in  position  by  the  orbital  fascia  and 
capsule  of  Tenon  with  its  orbital  prolongations,  is  moved  round  a 
point  on  its  antero-posterior  axis,  situated  (in  the  emmetropic  eye) 
1-4  mm.  behind  the  cornea,  and  10  mm.  in  front  of  the  posterior 
surface  of  the  sclerotic.  Its  motions  are  affected  by  means  of  the 
six  orbital  muscles,  arranged  in  three  pairs,  each  pair  consisting  of 
two  antagonistic  muscles  ;  thus  the  rectus  internus  and  rectus 
externus  are  antagonists,  the  former  rotating  the  eye  inwards,  and 
the  latter  rotating  it  outwards.  The  remaining  pairs  are  the  recti 
superior  and  inferior,  and  the  obliqui  superior  and  inferior. 

The  Primary  Position  of  the  Eyeball  is  that  one  in  which,  the 
head  being  held  erect,  the  gaze  is  directed  straight  forwards  in  the 
horizontal  plane.  This  is  the  starting-point  from  which  the  actions 
of  the  muscles  are  considered.  In  this  position  the  visual  axes 
are  parallel. 

The  Rectus  Externus  and  Pectus  Internus,  lying  from  their  origin 
to  their  insertion  in  a  plane  which  corresponds  with  that  of  the  hori- 
zontal plane  of  the  eyeball,  move  the  latter  on  its  perpendicular 
axis  directly  inwards  and  outwards,  and  have  no  other  action. 

The  Superior  and  Ijiferior  Recti  arise  at  the  back  of  the  orbit  to 
the  inner  side  of  the  eye,  and  pass  forwards  and  outwards.  There- 
fore the  plane  of  these  muscles  does  not  correspond  with  the  antero- 
posterior vertical  plane  of  the  eyeball,  but  passes  from  within  and 
behind,  forwards  and  outwards.  Consequently  their  axis  of  rotation, 
though  lying  in  the  horizontal  plane,  is  not  the  horizontal  axis  of 
the  eyeball,  but  one  which,  passing  from  within  and  before,  back- 

466 


CHAP.  xvrr. 


THE    ORBITAL    MUSCLES. 


467 


wards  and  outwards,  forms  with 
the  antero-posterior  axis  an  angle 
of  70°  (Fig.  186).  Being  inserted 
in  front  of  the  centre  of  rotation, 
their  action  is  mainly  to  rotate  the 
eyeball  upwards  and  downwards, 
but,  coming  from  the  inner  side, 
they  also  rotate  it  somewhat  in- 
wards. Moreover,  the  superior 
rectus  gives  to  the  vertical  meri- 
dian   of    the    cornea    an    inward 


inclination. 


or     inwar( 


^heel- 


motion,  or  torsion  of  the  eye  {vide 
infra),   while   the    inferior    rectus 

gives  this  meridian  an  outward  .inclination,  or  outward  wheel- 
motion  of  the  eye.  The  power  of  these  muscles  over  the  upward 
and  downward  motions  is  greatest  when  the  eye  is  turned  out,  for 
then  their  axis  of  rotation  coincides  most  closely  with  the  hori- 
zontal axis  of  the  globe  ;  and  their  influence  over  the  wheel- 
motion  is  greatest  when  the  eye  is  turned  in,  for  then  their  axis 
of  rotation   coincides  most   closely  with  the   antero-posterior  axis 

of  the  globe. 

The  plane  of  the  Oblique  Muscles 
of  the  eyeball  also  approaches  the 
antero-posterior  vertical  plane  of 
the  eyeball,  the  axis  upon  which 
they  rotate  the  latter  passing  from 
within  and  behind,  forwards  and 
outwards,  and  making  with  the 
antero-posterior  axis  an  angle  of 
35°  (Fig.  187).  The  principal  ac- 
tion, accordingly,  of  the  oblique 
muscles  is  to  incline  the  vertical 
meridian  of  the  cornea  ;  the  superior 


Fig.   187.— Left  Eye. 


1  In  speaking  of  the  inclination  of  the  vertical  meridian  of  the  cornea 
it  is  the  upper  extremity  of  this  meridian  which  is  meant.  Inward  means 
toward  the  nose  or  median  plane  of  the  head,  and  outward  towards  the 
temple.  These  wheel-motions  are  sometimes  designated  by  the  terms 
intorsion  and  extorsion. 


4()8  DISEASES    OF    THE    EYE.  [ohap.  xvti. 

oblique  inclines  it  inwards  (wheel-motion  inwards),  the  inferior 
oblique  inclines  it  outwards  (wheel-motion  outwards).  In  addition 
to  this,  since  the  fixed  })oinl  fioni  which  they  act  is  at  the  front  of 
the  inner  side  of  the  orbit,  and  since  they  are  inserted  behind  the 
centre  of  rotation,  they  will  each  of  them  rotate  the  eyeball  out- 
wards. Moreover,  the  superior  oblique  will  move  the  eye  down- 
wards, and  the  inferior  oblique  will  move  it  upwards.  It  is  evident 
(Fig.  187)  that  the  power  of  the  oblique  muscles  over  the  upward 
and  downward  motions  of  the  eyeball  is  greatest  when  the  eye  is 
turned  in,  and  that  their  power  over  the  wheel-motion  is  greatest 
when  the  eye  is  turned  out. 

To  sum  up  then  :  Vertical  motion. — The  recti  move  the  eye  in 
the  direction  indicated  by  their  names,  the  superior  upwards  and 
the  inferior  downwards.  The  obliques  move  the  eye  in  the  opposite 
direction  to  their  names,  the  superior  oblique  moving  it  downwards, 
and  the  inferior  oblique  upwards. 

Horizontal  motion. — The  recti  move  the  eye  inwards,  the  obliques 
move  it  outwards. 

Wheel-motion  (torsion). — The  superior  (rectus  and  oblique) 
muscles  rotate  the  vertical  meridian  inwards  ;  the  inferior  (rectus 
and  oblique)  muscles  rotate  the  vertical  meridian  outwards.  The 
action  of  the  obliques  on  the  wheel-motion  is  greatest  when  th«  eye 
is  rotated  outwards,  and  of  the  recti  when  the  eye  is  rotated  inwards. 

It  may  also  be  noted  that  the  obliques  acting  together  would 
move  the  eye  directly  outwards,  the  other  actions  of  these  muscles 
neutralising  each  other  ;  similarly  the  superior  and  inferior  recti 
acting  together  would  rotate  the  eye  directly  inwards.  But  simul- 
taneous action  of  these  several  pairs  of  muscles  does  not  occur  under 
normal  conditions. 

1 .  In  the  Primary  Position  all  the  muscles  are  at  rest. 

2.  Motion  of  the  eyeball  directly  outwards  is  affected  by  the  ex- 
ternal rectus  alone,  and  motion  directly  inivards  by  the  internal 
rectus  alone. 

3.  Motion  of  the  eyeball  directly  upivards  and  directly  downwards 
is  effected  chiefly  by  aid  of  the  superior  and  inferior  recti.  .  But 
these  muscles  acting  alone  rotate  the  eye  slightly  inwards,  and  tilt 
the  vertical  meridian,  which  in  this  position  should  be  upright. 
The  assistance  of  the  obliques  is  therefore  necessary  to  counteract 
these  subsidiaiy  effects.     For  example,  the  superior  rectus  moves 


CHAP.    XVIT. 


THE    ORBITAL   MUSCLES. 


469 


the  eye  upwards  and  inwards,  and  inclines  the  vertical  meridian 
inwards  ;  the  inferior  oblique  moves  it  also  upwards,  but  at  the  same 
time  turns  it  outwards,  and  inclines  the  vertical  meridian  outwards, 
so  that  when  the  two  muscles  act  together,  the  second  and  third 
effects  mentioned  neutralise  each  other,  and  the  result  is  a  vertical 
motion  upwards.  Similarly,  the  inferior  rectus  requires  the  assis- 
tance of  the  superior  oblique. 

In  oblique  positions  of  the  eyes,  the  vertical  meridian  no  longer 
remains  vertical  but  becomes  tilted,  as  shown  in  Fig.  188  (compare 
with  Fig.  193). 

4.  Rotation  ujnvards  and  outwards  is  effected  by  the  superior 


Left  Eye 


Right  Eye 


Torsion  due  to 
OttUque  Miisrle: 


Torswn  due  to 
Vertical  Recti  Muscles 


Torsion  due  to 
Oblique  Muscles 


Fig.  188. — Illustrates  the  torsion  of  the  vertical  meridian  in 
oblique  positions  of  the  eyes.  In  motions  of  both  eyes  the  meridians 
are  inclined  in  the  same  manner,  as  at  2  and  2',  3  and  3'  and  so  on. 
Compare  this  with  Fig.    193. 

rectus,  inferior  oblique,  and  external  rectus  ;  but  since  in  an  out- 
ward position  of  the  eyeball  the  torsion  effect  of  the  obliques  is  at 
its  greatest,  while  that  of  the  recti  is  diminished  or  nil,  the  action 
of  the  inferior  oblique  in  this  respect  will  preponderate,  and  the 
vertical  meridian  will  therefore  be  inclined  outwards  (2'  or  4,  Fig.  188). 

5.  Rotation  downivards  and  outivards  is  due  to  the  action  of  the 
inferior  rectus,  superior  oblique,  and  external  rectus,  and  here  also 
the  torsion  effect  of  the  oblique  muscle  will  prevail,  and  the  vertical 
meridian  w^ill  be  inclined  inwards.     (3'  or  5,  Fig.  188.) 

6.  Upward  and  inward  rotation  is  produced  by  the  superior 
rectus,  inferior  oblique  and  internal  rectus.  l)iit  in  tlie  inward  position 


470  DISEASES   OF    THE   EYE.  [chap.  xvii. 

of  the  eyes  the  torsion  efiect  due  to  the  rectus  will  prevail  over  that 
due  to  the  inferior  oblique,  and  the  vertical  meridian  will  thus  be 
inclined  inivards.     (4'  and  2,  Fig.  188.) 

7.  In  rotation  downwards  and  inwards  the  inferior  rectus,  superior 
oblique,  and  internal  rectus  act  together  ;  and,  for  the  reason  just 
mentioned,  the  vertical  meridian  will  be  inclined  outwards  by  the 
inferior  rectus.     (5'  and  3,  Fig.  188.) 

The  movements  of  each  eye  have  been  considered,  so  far,  as 
taking  place  separately,  but  in  reality  the  eyes  move  together,  their 
movements  being  associated.  Parallel  movements  of  the  eyes  in 
various  directions  are  called  conjugate,  while  inward  rotation  of  the 
eyes,  for  the  purpose  of  fixation  of  near  objects,  is  known  as  con- 
vergence. Conjugate  movements  may  also  take  place  combined 
with  convergence. 

Movement  of  the  eyes  upwards  is  generally  accompanied  by 
slight  divergence,  and  movement  downwards  by  slight  convergence, 
owing  to  the  closer  proximity  of  objects  to  the  eyes  below  the  hori- 
zontal plane,  and  their  greater  distance  from  the  eyes  when  above 
that  plane. 

*  In  conjugate  movements  of  the  eyes  into  oblique  positions, 
even  with  parallel  visual  axes,  a  symmetrical  wheel-motion,  or 
torsion,  occurs,  as  shown  in  Fig.  188.  In  the  primary  position 
(P.  and  P^),  and  also  when  the  eyes  are  turned  directly  to  the  right, 
to  the  left,  upwards,  or  downwards,  the  vertical  meridians  of  the 
corneas  (as  indicated  by  the  lines  passing  through  the  pupils),  main- 
tain their  vertical  direction.  In  other  positions  this  meridian 
becomes  tilted  to  one  or  other  side,  but  in  the  same  direction  for 
each  eye.  For  example,  on  looking  to  the  left  and  upwards  the 
inclination  of  the  vertical  meridian  is  to  the  left  in  both  eyes  (Fig.  188, 
2'  and  2).  The  effect  of  motion  in  the  three  other  oblique  positions 
is  also  shown.  The  explanation  of  this  torsion  has  already  been 
given  when  the  movements  of  the  eyes  separately  were  discussed.^ 

*  The  muscles  which  act  together  in  conjugate  movements  are 
said  to  be  associates.     The  right  internal  rectus,  for  example,  is 

1  This  effect  is  often  called  "  false  torsion,"  because  it  is  not  directly 
duo  to  the  twisting  of  the  eye  on  its  antero-posterior  axis,  but  to  the  fact 
that  the  rotation  iuto  the  oblique  position  is  accomplished  by  movement 
of  the  eye  on  an  oblique  axis,  which  lies  in  the  equatorial  plane  (Listing's 
plane)  of  the  eyeball. 


CHAP.  XVII.]  THE   ORBITAL   MUSCLES.  471 

the  associate  of  the  left  external  rectus,  in  movements  of  both  eyes 
to  the  left.  In  the  vertical  movements  directly  upwards  and  down- 
wards, the  two  muscles  engaged  in  one  eye  are  associated  with  the 
corresponding  two  muscles  in  the  other  eye  ;  }3ut,  in  the  oblique 
positions,  the  muscles  which  are  mainly  associated  in  their  action 
are  those  of  which  the  names  are  opposed  in  every  way.  For  ex- 
ample, in  looking  to  the  left  and  upwards  (in  addition  to  the  lateral 
recti)  the  real  associates  are  the  left  suferior  rectus  and  the  right 
inferior  oblique  ;  because,  in  this  position,  the  axis  of  the  left  eye 
lies  in  the  plane  of  the  recti  muscles,  while  the  axis  of  the  right  eye 
lies  in  the  plane  of  the  oblique  muscles. 

Conjugate  motions  and  movements  of  convergence  are  the  only 
motions  of  the  eyes  which  can  be  accomplished  voluntarily.  Diver- 
gence of  the  eyes  is  not  possible  under  normal  conditions — it  would 
be  useless  for  binocular  vision.  Torsion,  or  rotation  round  an 
antero-posterior  axis,  which  has  been  described  above,  occurs,  within 
limits,  on  inclining  the  head,  the  object  being  to  keep  the  vertical 
meridian  vertical.  Very  slight  torsion  occurs  on  convergence  also. 
But  these  latter  actions  of  the  muscles  are  all  involuntary. 

*  Objective  and  Subjective  Localisation,  or  Orientation.— An 
image  of  the  field  of  vision  is  formed  on  the  retina,  and  the  image 
of  each  object  in  the  field  is  '  projected  '  outward  along  the  secon- 
dary axis  passing  through  the  nodal  point,  or  optical  centre  of  the 
eye,  to  its  proper  position  in  the  field.  This  relation  of  objects  to 
one  another  in  space  is  called  objective  localisation. 

Subjective  localisation  consists  in  the  appreciation  of  the  position 
of  the  body  and  of  the  eyes  in  relation  to  external  objects,  and  is 
gained  chiefly  through  the  sense  of  muscular  effort  necessary  to 
bring  the  eyes  into  position  for  the  fixation  of  those  surrounding 
objects.  Hence  arises  the  false  judgment  of  position  and  the  re- 
sulting giddiness,  caused  by  sudden  loss  of  power  in  the  orbital 
muscles. 

*  The  Field  of  Fixation. — The  field  of  fixation,  which  shows  the 
range  of  mobility  of  the  eyeball,  contains  all  points  that  the  eye 
can  successively  see  or  '  fix '  with  the  macula  lutea,  without  move- 
ment of  the  head.  It  can  be  measured  with  the  perimeter,  as  in 
testing  the  field  of  vision,  except  that  here  the  patient  is  made  to 
move  the  eye  as  far  as  possible  in  each  meridian,  and  the  limit  of 
each  movement  is  measured  by  observing  the  corneal  reflex  of  a 


472  DISEASES   OF    THE   EYE.  [chap.  xvii. 

candle  flame,  or  oplithalmoscope  mirror,  which  is  moved  along  the 
arc  of  the  perimeter.  The  binocular  field  of  fixation  contains  all 
points  which  can  be  seen  as  single  with  the  two  eyes  and  without 
movement  of  the  head.  The  averages  give,  for  movement  of  one 
eye,  inwards  44°,  outwards  46°,  upwards  44°,  and  downwards  50°. 

Strabismus. 

When  looking  at  any  object  with  both  eyes  it  is  necessary,  in 
order  to  avoid  seeing  double,  that  the  visual  axis  of  the  eyes  should 
meet  at  the  point  fixed.  When  this  does  not  take  place,  one  of  the 
eyes  must  be  in  a  faulty  position,  or,  as  it  is  commonly  termed,  it 
squints.  This  condition  is  called  Strabismus,  and  may  arise  either 
from  over-action  or  from  paralysis  of  one  of  the  muscles.  Strabis- 
mus may  occur  in  any  direction,  but  vertical  and  oblique  deviations 
are  less  common  than  the  convergent  or  divergent  forms. 

In  order  to  ascertain,  in  slight  cases,  which  of  the  two  is  the 
deviating  eye,  the  patient  is  made  to  fix  an  object,  and  one  eye,  say 
the  left,  is  rapidly  covered  with  the  surgeon's  hand  ;  then,  if  the 
right  eye,  which  is  not  covered,  make  no  movement,  it  must  have 
been  looking  at  the  object  before  the  left  one  was  covered  ;  but  if 
now,  on  covering  the  right  eye,  the  left  make  a  movement  in 
order  to  fix  the  object,  then  this  eye  must  be  the  squinting  one. 
The  movement  is  always  in  the  opposite  direction  to  the  devia- 
tion. For  instance,  if  the  eye  be  turned  inwards  too  much,  it  must 
of  course  turn  outwards  to  fix  the  object,  when  its  fellow  is  covered. 
Another  good  method  consists  in  observing  the  position  of  the 
corneal  reflex  when  the  patient  looks  at  the  ophthalmoscope  (see 
Measurement  of  Strabismus).  But  the  most  delicate  test  is  the 
character  of  the  diplopia,  if  diplopia  be  present. 

Apparent  Strabismus  is  due  to  a  large  angle  y  (p.  3).  In  this 
case,  as  the  visual  axes  are  both  directed  to  the  point  fixed,  there 
w^ill  be  no  movement  of  either  eye  on  covering  the  other,  as  in  true 
strabismus. 

Real  Strabismus  may  be  Paralytic,  Concomitant,  or  Latent. 

*  Latent  Strabismus,  also  called  Muscular  Insufficiency  or 
Heterophoria. — In  these  cases  strabismus  only  occurs  in  exceptional 
conditions,  such  as  the  use  of  tests  which  interfere  with,  or  render 
more    difficult,    binocular    vision.     Under    the    usual    conditions, 


CHAP.  XVII.]  THE    ORBITAL    MUSCLES.  473 

binocular  vision  is  maintained  in  these  cases,  but  this  involves  a 
muscular  effort  greater  than  normal,  and  hence  these  patients  suffer 
from  muscular  asthenopia. 

Binocular  Vision.  Sense  of  Fusion.— When  an  object  is  looked 
at,  the  visual  axes  meet  at  that  object  or  point  of  fixation  [binocular 
fixation),  and  the  two  retinal  images  are  fused  into  one  by  a  cerebral 
process,  so  that  the  object  appears  single.  This  constitutes  binocular 
single  vision.  All  objects  situated  about  the  same  distance  from  the 
eyes  and  in  that  portion  of  the  field  which  is  common  to  both,  form 
images  on  corresponding  parts  of  the  retina?,  and  they  too  are  per- 
ceived as  single.  The  slight  differences  in  the  images  of  an  object 
as  seen  from  the  point  of  view  of  each  eye  generate  the  perception 
of  relief  or  stereoscopic  vision,  which  is  the  highest  grade  of  binocular 
vision.  The  fusion  sense  — i.e.  the  mental  desire  for  single  vision — 
develops  in  infancy,  but  in  different  individuals  it  exists  in  different 
degrees.  Binocular  fixation  may,  for  instance,  be  present  without 
true  fusion,  only  one  of  the  images  being  perceived,  while  the  other 
is  suppressed  ;  as  is  proved  by  the  inability  sometimes  to  produce 
double  vision  by  means  of  a  prism.  Not  only  this,  but  the  sense 
of  fusion  is  more  easily  disturbed  in  some  persons  than  in  others, 
when  binocular  vision  is  rendered  difficult  by  artificial  means. 

The  existence  or  otherwise  of  true  binocular  vision  may  be  ascer- 
tained by  the  simple  experiment  of  giving  the  patient  a  book  to 
read,  and  then  holding  a  cedar  pencil  halfway  between  his  eyes  and 
the  page,  at  right  angles  to  the  lines  of  type.  If  binocular  vision 
be  present,  the  pencil  will  not  offer  any  impediment  to  the  reading  ; 
but,  if  it  be  not  present,  parts  of  the  page  will  be  hidden  behind  the 
pencil.  The  reader  may  prove  this  by  performing  the  experiment  on 
himself,  first  with  both  eyes  open  (binocular  vision),  and  then  with 
one  eye  shut. 

Another  method  is  that  known  as  Bering's  Drop  Experiment. 
A  hollow  cylinder  about  25  cm.  long,  and  wide  enough  to  take  in  both 
eyes  of  a  person,  is  provided — at  the  opposite  end  from  that  placed 
around  the  eyes — with  two  strong  wires  18  inches  long,  which  jut 
out  in  continuation,  as  it  were,  of  the  cyhnder,  but  which  are  bent 
outwards  sufficiently  to  keep  them  out  of  the  view  of  the  patient. 
Between  the  ends  of  these  wires  a  fine  thread  is  stretched,  with  a 
small  bead  fastened  at  its  middle  point,  so  that  the  bead  may  occupy 
the  centre  of  the  field  when  the  patient  looks  through  the  cylinder. 


474  DISEASES   OF    THE   EYE.  [chap.  xvii. 

During  the  experiment  the  thread  is  in  the  horizontal  position,  and 
the  bead  is  used  as  the  patient's  fixation  point.  Small  balls  of 
different  sizes  (peas,  beans,  etc.)  are  then  let  fall  from  a  height,  one 
after  another,  a  couple  of  dozen  times  or  more,  some  of  them  in  front 
of  the  tliread,  some  of  them  behind  it.  If  the  patient  have  normal 
binocular  vision,  he  will  be  able  to  say  each  time  with  certainty 
whether  the  ball  falls  in  front  of,  or  behind  the  thread  ;  but  if  he 
have  not  true  binocular  vision,  if  only  one  eye  be  used,  he  will  merely 
guess  at  the  position  of  the  falling  ball,  and  will  make  frequent 
mistakes. 

Binocular  Vision  can  also  be  tested  by  the  stereoscope  in  its 
various  forms,  or  by  the  amblyoscope,  the  diploscope,  or  diaphragm 
test. 

Diplopia,  or  double  vision,  always  occurs  in  the  absence  of  bin- 
ocular fixation — i.e.  when  strabismus  is  present — provided  binocular 
vision  had  previously  existed.  One  image  is  seen  by  each  eye,  and 
the  double  vision  disappears  on  closing  one  eye.  This  is  binocular 
diplopia,  as  distinguished  from  monocular  diplopia,  in  which  two 
images  are  formed  on  the  retina  of  one  eye,  as  the  result  of  irregular 
refraction  (incipient  cataract,  dislocated  lens,  irregular  astigmatism, 
double  pupil). 

The  image  seen  by  the  eye  which  looks  at,  or  fixes,  the  object 
is  called  the  '  true  image.'  That  which  corresponds  with  the  de- 
viated eye  is  the  '  false  image  '  ;  and,  as  it  does  not  lie  on  the  macula 
lutea,  it  appears  less  distinct  than  the  former.  The  false  image 
always  appears  to  the  patient  to  be,  or  is  '  projected  '  by  him,  in 
the  opposite  direction  to  the  displacement  of  the  eye,  so  that  the 
diplopia  is  the  reverse  of  the  position  of  the  eyes. 

When  the  image  seen  by  the  affected  eye  lies  to  the  correspond- 
ing side,  the  diplopia  is  termed  homonymous.  Homonymous  double 
vision  therefore  always  indicates  convergence  of  the  visual  lines. 
Fig.  189  explains  the  occurrence  of  homonymous  diplopia  in  con- 
vergent paralytic  strabismus.^  The  right  eye  fixes  the  object  o, 
and  its  image  falls  on  the  macula  lutea  m  ;  but  the  left  eye,  by 
reason  of  paralysis  of  the  external  rectus,  is  turned  in,  and  its  visual 
axis  lies  in  the  direction  m  v,  and  the  image  of  o  falls  to  the  inner 

^  For  the  sake  of  simplicity  in  the  diagram  tlie  effect  which  rotation 
of__the  eye  has  on  the  nodal  point  is  omitted. 


CHAP.    XVII,] 


THE   ORBITAL    MUSCLES. 


475 


side  of  the  macula  liitea  at  a.  Now  why  should  this  image  not  be 
referred  to  its  correct  position  along  the  line  a  o  ?  The  reason  is 
that  the  patient  is  not  conscious  of  the  deviation  of  this  eye  ;  and, 
having  always  been  in  the  habit  of  superposing  his  fields  of  vision, 
so  that  the  visual  axes  of  the  eyes  meet  at  the  object  fixed,  he 
imagines  this  to  be  still  the  case,  and  that  v  m  lies  in  the  position 
of  0  a,  and  that  the  macula  lutea  m  is  at  m^  But  if  this  were  so, 
a  would  be  at  a' ,  and  in  this  position  of  the  eye,  images  formed  at 
ci   to  the  inner  side  of  the  macula  lutea  are  projected  to  the  outer 

V 


ni']  f   a' 

Left  Eye.  Right  Eye. 

Fig.   189. 

side  of  the  field,  along  the  line  a   o\  and  the  patient  imagines  that 
0  occupies  the  position  o",  as  seen  with  the  left  eye. 

If  the  left  eye  were  deviated  outwards,  the  image  of  o  would  fall 
to  the  outside  of  the  macula,  and  would  therefore  be  projected  to 
the  right  of  the  true  position  of  the  object.  The  right  image  w^ould 
then  belong  to  the  left  eye  and  vice  versa  ;  this  is  crossed  diplopia, 
and  indicates  divergence  of  the  visual  lines.  A  very  simple  experi- 
ment will  prove  this  :  when  a  finger  is  held  up  in  front  of  the  eyes, 
and  a  distant  object  is  fixed,  it  will  be  noticed  that  the  finger  is  seen 
double  ;  if  now  the  right  eye  be  closed,  the  left  image  of  the  finger 
will  vanish.  The  diplopia  here  is  crossed  because  the  convergence 
of  the  eyes  is  less  than  that  required  for  fixing  the  finger — there  is,  in 


470  DISEASES   OF    THE   EYE.  [chap.  xvit. 

fact,  a  relative  divergence.  If  the  finger  be  now  fixed,  a  bright 
object  farther  away  will  be  seen  double,  but  the  diplopia  will  be 
homonymous,  because  the  eyes  are  convergent.  This  is  a  physiolo- 
gical diplopia,  to  which  we  habitually  pay  no  attention,  and  as 
the  images  are  formed  on  parts  of  the  retina  other  than  the  macula 
lutea,  we  are  not  disturbed  by  its  existence,  although  it  uncon- 
sciously enables  us  to  locate  the  position  of  objects  as  being  nearer 
or  farther  than  the  object  fixed. 

When  an  eye  is  deviated  upwards  or  downwards,  the  correspond- 
ing image  is  projected  downwards  or  upwards  ;  and  torsion  of  the 
vertical  meridian  in  one  direction  produces  a  tilting  of  the  image  in 
the  opposite  direction. 

For  the  effect  of  prisms  on  the  production  and  correction  of 
diplopia,  see  chap.  xv.  §  9. 

It  is  necessary  that  the  foregoing  shall  have  been  clearly  under- 
stood, before  the  study  of  paralysis  of  the  orbital  muscles  is 
approached. 

Paralyses  of  the  Orbital  Muscles. 

We  shall  now  consider  the  symptoms  produced  by  paralysis  of 
the  orbital  muscles  without  regard  to  the  nature  or  seat  of  the 
causative  lesion.  These  symptoms  may  be  general,  that  is  to  say, 
common  to  all  the  muscles,  or  special — that  is  to  say,  dependent 
on  the  particular  muscle  affected. 

General  Symptoms.— (1)  Strabismus  due  to  the  action  of  the 
opponent  muscle.  This  is  called  the  primary  deviation.  (2)  Loss 
or  diminution  of  movement  in  the  direction  of  normal  action  of  the 
affected  muscles.  (3)  Diplopia,  due  to  the  strabismus  ;  or,  if  the 
paralysis  be  but  slight,  actual  diplopia  may  not  be  present,  but  the 
double  images  overlapping  each  other  will  cause  dimness  or  con- 
fusion of  sight.  (4)  Giddiness  and  uncertain  gait,  due  partly  to  the 
diplopia,  and  partly  to  faulty  projection  of  the  object.  (5)  False 
projection,  by  which  is  meant  the  false  conception  of  the  position  of 
the  image  in  the  field  of  fixation.  It  causes  difficulty  in  walking  and 
working,  and  is  most  noticeable  when  a  depressor  muscle  is  affected. 
(6)  Some  patients  turn  the  head  towards  the  side  of  the  paralysed 
muscle,  in  order  to  diminish  or  eliminate  the  diplopia — e.g.  if  the 
left  ext.  rectus  were  paralysed,  the  head  would  ])e  tui-ned  towards 


CHAr.   xviT.]  THE    ORBITAL    MUSCLES.  477 


the  left ;  if  it  were  the  left  int.  rectus,  the  head  would  be  turned 
towards  the  right.  By  this  manoeuvre  the  loss  of  the  action  of  the 
affected  muscle  is  less  felt  for  those  objects  which  lie  straight  in  the 
patient's  path,  while  he  walks  about ;  because  it  involves  a  rotation 
of  the  eye  towards  the  side  of  the  healthy  antagonist,  in  which 
region  of  the  binocular  fixation  field  the  diplopia  is  reduced  to  a 
minimum.  Some  patients  close  one  eye,  usually  the  affected  one, 
to  procure  single  vision.  It  will  be  noted  that  1,2,  and  6  are  objective 
symptoms,  while  3,  4,  and  5  are  subjective. 

In  peripheral  paralysis  it  is  most  common  to  find  only  the  muscle, 
or  muscles,  supplied  by  some  one  nerve — the  third,  fourth,  or  sixth 
— affected  ;  although,  of  course,  exceptions  to  this  are  not  rare, 
especially  where  a  neoplasm  forms  at  the  base  of  the  skull. 

In  studying  a  case  of  paralysis  of  an  orbital  muscle  the  following 
.  General  Principles  should  be  borne  in  mind  : — (1)  The  defective 
mobility  and  the  diplopia  increase  towards  the  side  of  the  affected 
muscle — towards  the  left,  if  the  left  external  rectus  be  paralysed  ; 
towards  the  right,  if  the  left  internal  rectus  be  paralysed.  The  image 
which  is  farthest  in  the  direction  in  which  the  diplopia  increases 
belongs  to  the  paralysed  eye.  (2)  The  secondary  deviation  {i.e.  the 
deviation  of  the  sound  eye  while  the  affected  eye  fixes)  is  greater 
than  the  primary  deviation  ;  because  the  muscle  in  the  sound  eye, 
which  is  associated  in  its  action  with  the  paralysed  muscle  in  the 
affected  eye  (e.g.  the  rect.  int.  with  the  rect.  ext.),  must  receive  a 
nervous  impulse  of  equal  intensity  to  that  sent  to  the  weak  muscle, 
and,  as  the  latter  requires  a  considerable  impulse  to  excite  its  action, 
its  associate  will  be  over-excited.  Let  us  suppose  the  left  external 
rectus  to  be  paralysed,  and  that,  shading  the  right  eye  with  a  hand, 
we  direct  the  patient  to  fix  with  his  left  eye  an  object  held  somewhat 
to  his  left  side  ;  we  may  notice,  on  removing  the  shading  hand,  that 
the  right  eye  has  been  rotated  inwards  to  an  extent  far  exceeding 
that  of  the  primary  deviation  of  the  left  eye,  and  has  now  to  make 
an  outward  motion  in  order  again  to  fix  the  object.  (3)  The  image 
formed  on  the  retina  of  the  affected  eye  is  projected  {i.e.  seems  to 
the  patient  to  lie)  in  the  direction  of  the  paralysed  muscle  ;  in  other 
words,  the  position  of  the  false  image  corresponds  with  the  normal 
action  of  the  paralysed  muscle,  because  the  deviation  of  the  eye 
is  in  the  opposite  direction  to  the  action  of  the  paralysed  muscle — 
e.g.  if  the  left  ext.  rect.  be  paralysed,  the  image  corresponding  with 


478  DISEASES    OF    THE   EYE.  [chap.  xvti. 

that  eye  will  be  projected  to  the  left  of  the  image  belonging  to  the 
right  eye.  (8ee  Diplopia,  p.  474.)  When  the  affected  eye  fixes  alone, 
the  faulty  projection  is  twice  as  great  as  when  fixation  is  binocular. 
(See  General  Principle,  No.  2.) 

The  deviation  of  the  eye,  the  strabismus,  alone  is  in  the  opposite 
direction  to  the  paralysed  muscle  ;  all  the  other  signs,  defective 
mobility,  false  projection,  increase  of  diplopia,  secondary  deviation, 
and  position  of  the  head,  are  towards  the  paralysed  muscle. 

The  Special  Symptoms  due  to  paralysis  of  individual  muscles 
will  now  be  considered. 

Paralysis  of  the  External  Rectus  of  the  Left  Eye.— If  this  be 
complete  or  considerable,  it  is  easy  of  diagnosis  for  along  with  con- 
vergent strabismus  there  is  marked  loss  of  power  and  motion  of  the 
left  eyeball  outwards,  and  the  patient  complains  of  double  vision. 
He  keeps  his  head  turned  to  the  left,  in  order  to  diminish  the  in- 
fluence of  the  paralysed  muscle  as  much  as  possible. 

If,  however,  the  paralysis  be  but  slight,  the  patient  may  not  com- 
plain decidedly  of  diplopia,  but  only  of  indistinctness  or  confusion 
of  sight,  especially  when  he  looks  towards  the  left.  To  decide  the 
diagnosis  in  such  a  case,  the  double  images  must  be  examined.  A 
long  lighted  candle  is  used  as  the  object  to  be  looked  at ;  and  one 
eye — let  us  say  here  the  left  eye — is  covered  with  a  bit  of  red-stained 
glass  in  order  to  differentiate  the  images.^  The  candle  is  now  held 
on  a  level  with  the  patient's  eyes,  and  straight  opposite  him, 
about  three  metres'  distance  (eyes  in  primary  position),  (a)  In  this 
position  the  images  are  seen  very  close  together  or  overlapping  each 
other,  both  of  them  upright  and  oh  the  same  level,  the  red  candle  to 
the  left,  the  white  to  the  right — i.e.  homonymous  diplopia  =  con- 
vergence. This  convergence  must  be  due  to  paralysis  of  one  or 
other  external  rectus  muscle,  but  we  cannot  say  at  this  stage  of  the 
experiment  which  of  them  is  affected.  (6)  In  order  to  determine 
this  point,  the  candle  must  be  carried  from  side  to  side,  and  the  in- 
creasing or  decreasing  distance  of  the  images  from  each  other  noted. 
If  the  candle  be  carried  slowly  to  the  right,  the  patient  following  it 
with  his  eyes  without  turning  his  head,  the  images  come  closer 
together,  or  only  one  candle  is  seen.     But  if  the  candle  be  carried  to 

*  Maddox's  Rod  Test,  described  farther  on,  is  very  suitable  here,  and 
in  the  investigation  of  other  forms  of  ocular  palsy. 


CHAP.  XVII.]  THE  ^ORBITAL    MUSCLES.  470 


the  patient's  left,  the  images  go  farther  apart,  their  relative  posi- 
tions being  maintained.  We  now  know  that  it  is  the  left  external 
rectus  which  is  affected  :  because  towards  the  left — the  direction  in 
which  the  action  of  this  muscle  is  most  wanted,  and  consequently  its 
loss  most  felt — the  distance  between  the  double  images  increases. 
The  images  are  erect,  as  no  wheel-motion  is  caused  by  action  of  the 
external  rectus.  (c)  If,  liowever,  the  candle  be  held  to  the  left  and 
raised  aloft,  the  image  belonging  to  the  left  eye  will  seem  to  lean 
away  from,  and  to  be  a  little  lower  than,  that  of  the  right  eye  (Fig. 
190).  The  reason  of  this  is  that,  owing  to  the  paralysis  of  the  external 
rectus,  the  left  eye  cannot  look  sufficiently  outwards,  but  merely 
looks  upwards.  The  inferior  oblique  loses  some  of  its  torsional 
power,  but  retains  a  greater  power  of  elevation.  The  left  eye  there- 
fore is  higher  than  the  right,  and  its  vertical  meridian  remains 
vertical.  But  the  right  eye,  which  is  free  to 
follow  the  candle,  looks  up  and  to  the  left.     Its      ^  ^] 

vertical  meridian  is  therefore  inclined  to  the 
left.  That  is,  the  vertical  meridians  of  the 
two  eyes  converge  at  the  top,  which  necessitates 
a  divergence  of  the  upper  extremities  of  the 
images.  The  rotation  of  the  right  eye  in  this 
position  is  physiological,  and  its  image  is  there-  -^^^   ^QO 

fore  judged  to  be  vertical ;  while  the  image 
of  the  left  eye  diverging  from  that  of  the  right,  though  really 
vertical,  is  judged  to  be  oblique.  An  analogous  displacement  of 
the  eye  downwards,  and  defective  rotation  of  the  vertical  meridian 
due  to  the  superior  oblique,  takes  place  in  the  position  below  and  to 
the  outside,  (d)  If  the  patient  be  told  to  direct  his  gaze  specially  to- 
wards the  red  candle — i.e.  the  image  which  belongs  to  the  left,  the 
affected,  eye — the  distance  between  the  two  candles  will  be  much 
greater  than  if  he  direct  his  gaze  towards  the  white  candle.  This  is 
explained  by  ^General  Principle  No.  2  (p.  477). 

•  If  the  patient's  good  eye  be  closed,  and  an  object  (surgeon's 
finger)  be  held  up  within  his  reach,  but  towards  his  left  side,  and  he 
be  requested  to  aim  rapidly  at  it  with  his  forefinger,  he  will  aim  to 
the  left  of  it.  The  nervous  impulse  sent  to  his  left  external  rectus, 
to  enable  him  to  turn  the  eye  towards  the  object,  is  of  such  intensity 
as  to  lead  him  to  fancy  that  the  object  lies  much  farther  to  the  left 
than  is  the  case  (incorrect  projection  of  the  field  of  view)  ;   for  we,  to 


480  DISEASES    OF    THE   EYE.  [ru.w.   xvn. 

a  great  extent,  estimate  the  distance  of  objects  from  each  other  by 
the  amount  of  nervous  impulse  supplied  to  our  orbital  muscles  in 
motions  of  the  eyeball. 

A  prism  held  horizontally  before  the  atl'ected  eye  with  its  base 
outwards  brings  the  double  images  closer  together ;  or,  if  the  correct 
prism  be  selected,  the  iin;iges  will  he  blended  into  one. 

*  Paralysis  of  the  Superior  Oblique  of  the  Left  Eye.— This 
paralysis  will  be  most  apparent  when  a  demand  is  made  for  motion 
of  the  eyeball  downwards  and  inwards,  the  action  of  the  superior 
oblique  as  a  depressor  being  greatest  in  this  position.  Yet  absolute 
defect  of  motion  is  sometimes  difficult  to  detect,  even  in  complete 
paralysis  of  this  muscle,  owing  to  vicarious  action  of  the  inferior 
rectus  and  of  the  internal  rectus.  Careful  examination  of  the  secon- 
dary deviation  will  often  be  successful  as  to  this  point.  But  it  is 
on  the  examination  of  the  double  images  that  we  must  chiefly  rely 
for  the  diagnosis,  as  follows  : — 

(a)  In  the  whole  of  the  field  of  vision  above  the  horizontal  plane 
there  is  single  vision.  Below  the  horizontal  plane  in  the  median  line 
diplopia  appears,  the  image  belonging  to  the  left  eye  standing  lower 
than  that  belonging  to  the  right :  because  the  superior  oblique  being 
a  muscle  which  assists  in  rotating  the  eye  downwards,  the  latter,  for 
want  of  the  action  of  this  muscle,  now  stands  higher  than  its  fellow 
(right  eye).  The  position  downwards  and  inwards  of  the  eyeballs  is 
that  in  which  the  greatest  demand  is  made  upon  the  superior  oblique 
for  rotation  of  the  eye  downwards  :  therefore  it  is  in  this  position 
its  want  for  this  purpose  is  most  felt ;  and  wdien  the  candle  is  held 
in  this  position,  the  vertical  distance  between  the  double  images  is 
greatest,  (h)  The  superior  oblique  assists  also  in  rotation  of  the 
eye  outwards  :  therefore  loss  of  its  power  must  commit  the  eyeball 
to  a  certain  extent  to  the  power  of  the  muscles  which  move  it  inwards, 
and  a  rotation  in  this  latter  direction  (convergence)  takes  place,  with 
the  result  of  making  the  image  belonging  to  the  left  eye  stand  to  the 
left  of  the  image  belonging  to  the  right  eye  (homonymous  diplopia), 
(c)  The  superior  oblique  inclines  the  vertical  meridian  inwards  : 
therefore,  in  rotation  directly  downwards,  loss  of  its  power  commits 
the  eye  to  the  outward  wheel-motion  imparted  to  it  by  the  inferior 
rectus.  This  gives  to  the  image  belonging  to  the  left  eye  an  inclina- 
tion to  the  patient's  right  hand,  (d)  The  power  of  the  superior 
oblique  to  incline  the  vertical  meridian  inwards  is  greatest  when  the 


CHAP.  XVII.]  THE    ORBITAL    MUSCLES.  481 

eye  is  turned  downwards  and  outw^ards  :  consequently,  in  this 
respect  its  paralysis  will  be  felt  chiefly  in  this  position,  and  therefore 
here  the  inclination  of  its  image  to  that  of  the  sound  eye  will  be  most 
marked,  (e)  A  remarkable  phenomenon  usually  noticed  in  this 
paralysis  (and  sometimes  in  paralysis  of  the  inferior  rectus)  is  that 
the  image  belonging  to  the  affected  eye  seems  to  stand  nearer  the 
patient  than  that  of  the  sound  eye.  This,  it  is  believed,  is  due  to 
the  fact  that  the  lower  image  is  projected  on  a  plane  nearer  to  the 
patient,  say  where  it  appears  to  meet  the  floor. 

To  sum  up,  then  (Fig.  191)  :  below  the  horizontal  plane  there 
is  homonymous  diplopia,  while  the  image  (^4)  of  the  affected  eye 
stands  on  a  lower  level,  is  inclined  tow^ards  the  other  image,  and 
seems  to  be  nearer  the  patient.     Furthermore  : — 

(/)  In  an  extreme  lower  and  outer  position  the  image  of  the 
affected  eye  may  sometimes  seem  to 
stand  higher  than  that  of  the  sound 
eye,  owing  to  an  excessive  outward 
inclination  of  the  vertical  meridian, 
which  throws  the  image  on  the  lower 
and  inner  quadrant  of  the  retina. 

In   order   to   do   away  with  or  to 
diminish    the    diplopia,    the    patient       ^y^ A 
inclines  his  head  forwards  and  towards 
the  right  shoulder,  and  turns  his  face  ^^^-  1^^- 

towards  the  side  of  the  good  eye. 

For  the  prismatic  correction  of  the  diplopia,  two  prisms  will  be 
required ;  one  with  its  base  downwards  in  front  of  the  left  eye,  to 
correct  the  vertical  difference,  and  a  second  with  its  base  outwards 
in  front  of  the  right  eye,  to  correct  the  lateral  difference,  or  it  may 
be  possible  to  correct  it  by  a  single  prism  in  an  oblique  position. 

Paralysis  of  the  Third  Nerve  (Internal  Rectus,  Superior  Rectus, 
Inferior  Rectus,  Inferior  Oblique,  and  Levator  Palpebrae).— Com- 
plete paralysis  of  all  the  branches  of  the  third  nerve  produces  a 
remarkable  appearance.  The  upper  lid  droops  (ptosis),  the  eyebrow 
is  raised — from  compensatory  action  of  the  occipito-frontalis — the 
pupil  is  semi-dilated  and  immovable,  the  power  of  accommodation 
is  destroyed,  and  the  eyeball  is  often  slightly  protruded,  owing  to 
the  backward  traction  of  the  recti  being  wanting.  There  is  divergent 
strabismus.  Motion  inwards  exists  but  to  a  slight  degree,  and  motion 
31 


482 


DISEASES   OF    THE   EYE. 


[chap.    XVI 


downwards  and  outwards  is  effected  only  by  aid  of  the  superior 
oblique,  and  is  accompanied  by  marked  inward  wheel-motion,  which 
can  be  detected  best  by  noting  the  change  in  position  of  a  con- 
junctival vessel.  If  the  paralysis  be  of  some  little  standing,  the 
external  rectus  obtains  rule  over  the  eyeball,  and  rotates  it  perma- 
nently outwards. 

The  diagnosis,  in  cases  of  complete  paralysis  of  all  branches  of 
the  nerve,  is  easily  made  ;  but  not  so  sometimes,  if  the  paralysis  be 
only  slight,  and  here  the  examination  of  the  double  images  is  of 
value,  as  follows  : — 

If  (Fig.  192)  the  left  third  nerve  be  partially  paralysed  in  all 


Fig.   192. 


or  most  of  its  branches,  there  will  be  crossed  diplopia  either  in  the 
whole  of  the  field  of  vision — for  want  of  power  in  the  internal  rectus 
— or  towards  the  patient's  right  at  the  least,  and  the  lateral  distance 
between  the  images  will  increase  as  the  visual  object  is  carried 
farther  towards  the  right.  When  the  visual  object  is  held  aloft  the 
left  eye  will  not  follow  it — for  want  of  the  action  of  the  two  muscles 
which  turn  the  eye  upwards — and,  consequently,  in  this  position  its 
image  will  stand,  not  only  to  the  right  of  but  also  above  that  of  the 
right  eye  ;  while,  when  the  visual  object  is  held  below  the  horizontal 
plane,  the  eye  will — owing  to  paralysis  of  the  inferior  rectus — remain 
higher  than  the  right  eye,  and  consequently  its  image  will  appear  to 
be  lower  than  that  of  the  right  eye.  It  will,  moreover,  be  inclined 
towards  the  latter  image,  in  consequence  of  the  inward  wheel-motion 
imparted  to  the  eye  by  the  healthy  superior  oblique. 


CHAP.    XVII. 


THE   ORBITAL   MUSCLES. 


483 


AVlien  some  branches  of  the  third  nerve  are  paralysed  in  each  eye, 
the  diagnosis  is  often  extremely  complicated.  The  ptosis,  however, 
which  is  nearly  always  present,  and  is  readily  recognised,  and  the 
paralysis  of  the  sphincter  iridis  (mydriasis)  and  of  accommodation, 
which  often  exist,  and  are  also  easily  observed,  give  valuable  aid. 
Moreover,  any  loss  of  motion  upwards  must  be  due  to  paralysis  of  the 
third  nerve  ;  but  if  there  be  loss  of  motion  downwards,  the  differ- 
ential diagnosis  between  paralysis  of  the  inferior  rectus  (3rd  Nerve) 
and  of  the  superior  oblique  (4th  Nerve)  has  to  be  made.  For  this 
see  the  paragraph  on  paralysis  of  the  latter  muscle. 

As  may  be  imagined  from  the  foregoing,  it  is  often  difficult  in 
practice  to  keep  clearly  before  one's  mind  the  different  actions  of 
the  orbital  muscles,  and  from  the  character  of  the  diplopia  to  deduce 
the  paralysis  which  may  be  present.  The  mnemonic  diagram 
here  given  (Fig.  193)  will  assist  in  this  respect,  and  it  will  serve  also 
as  a  control  in  reasoning  on  this  subject. 

The  larger  circles  in  Fig.  193  indicate  the  position  of  the  cornea 
resulting  from  the  action  of  the  elevator  and  depressor  muscles  of 
the  eye  ;  the  smaller  central  circles  represent  the  pupils.     R  and  R 


Oblique  Muscles       Recti  Muscles 


LIO 


0 


LS.R 


L.S.O. 


LIR 


RSR 


Oblique  MiiscUs 
RIO 


T^x 


O 


RIR 


RSO 


Un  Eye 


Right  Eye 


Fig.   193. — Diagram  illustrating  the  separate  actions  of  the  elevator 
and  depressor  muscles.     R.I.O.   =  Right  Inferior  Oblique,  and  so  on. 


represent  the  anterior  extremities  of  the  axes  of  rotation  of  the  recti 
muscles,  which  lie  to  the  inner  side  of  the  cornea,  and  0  and  0 
similarly  the  extremities  of  the  axis  of  rotation  of  the  obliques  at 
the  outer  side  of  the  cornea.     The  dotted  arcs  of  circles  are  those 


484  DISEASES    OF    THE    EYE.  [chap.   xvit. 


described  by  the  centre  of  the  cornea  in  rotation  of  the  eyes  on  these 
axes.  The  two  central  arcs  with  their  concavities  tow^ards  each 
other  represent  the  action  of  the  recti  muscles,  and  the  two  outer 
arcs  the  action  of  the  obliques.  The  vertical  meridian  of  the  cornea, 
indicated  by  a  line  passing  through  its  centre,  is  tangential  to  the 
circles  described  by  the  centre  of  the  cornea,  and  consequently, 
when  one  muscle  acts  at  a  time,  this  meridian  can  be  vertical  only 
in  the  primary  position. 

Now,  to  find  the  action  of  the  right  superior  rectus,  it  is  merely 
necessary  to  look  at  the  right  superior  quarter  of  the  centre  of  the 
figure  (R.S.R.)  and  it  will  be  seen  at  once  that  this  muscle  moves  the 
eye  inwards,  upwards,  and  inclines  the  vertical  meridian  inwards. 
In  the  same  way  the  action  of  an  oblique  muscle  w^ill  be  found  in 
the  outer  portion  of  the  figure  on  its  own  side,  but  as  the  vertical 
action  of  the  obliques  is  in  a  direction  opposite  to  that  indicated 
by  their  names,  the  superior  oblique  will  be  found  below  and  the 
inferior  above.  The  action  of  the  left  inferior  oblique  is  found  in 
the  outer  portion  of  the  figure,  on  the  left  side,  above  (L.I.O.). 

Many  facts  can  at  once  be  understood  by  reference  to  the  figure  : 
for  example,  that  the  recti  are  inward  rotators  or  adductors,  and 
the  obliques  outward  rotators  or  abductors  ;  that  the  superior 
muscles  produce  inward  torsion  (R.S.R.,  L.S.R.,  R.S.O.,  and  L.8.O.), 
and  the  inferior  muscles  outw^ard  torsion  (R.I.R.,  L.I.R.,  R.I.O., 
and  L.I.O.)  ;  also,  that  the  right  superior  rectus  (R.8.R.)  for  instance, 
is  the  true  associate  of  the  left  inferior  oblique  (L.I.O.) ,  their  action 
corresponding  in  all  three  respects — namely,  motion  upward,  to 
the  left,  and  torsion  to  left,  and  so  on.^ 

Now,  since  the  deviation  of  the  eye  is  in  the  opposite  direction 
to  the  normal  action  of  the  paralysed  muscle,  and  the  projection 
of  the  false  image  is  the  opposite  of  the  position  of  the  eye,  it  follow^s 
that  the  false  image  must  appear  displaced  in  the  direction  of  the 

1  The  action  of  the  muscles  is  considered  as  if  the  observer  were  looking 
at  his  own  eyes  from  behind.  This  view  is  taken  in  order  that  this  figure 
may  correspond  with  Fig.  194,  illustrating  the  diplopia,  in  which  also 
the  observer  considers  himself  to  be  the  patient.  To  be  quite  accurate 
it  should  be  remembered  that  as  the  cornea  moves  out  of  the  primary 
position,  it  comes  to  lie  more  and  more  behind  the  plane  of  the  paper  in 
the  figure.  In  fact  the  arcs  of  circles  are  seen  sideways  and  therefore 
appear  elliptical.  The  idea  of  this  figure  was  suggested  by  Landolt's 
method  of  demonstrating  the  action  of  the  muscles  on  a  rubber  ball. 


CHAP.    XVII.] 


THE   ORBITAL   MUSCLES. 


485 


action  of  the  muscle,  therefore  Fig.  194,  illustrating  the  diplopia, 
is  practically  the  same  as  Fig.  193. 

In  Fig.  194  the  form  of  diplopia  which  characterises  paralysis 
of  each  muscle  is  expressed  by  the  position  of  the  dotted  candle 
bearing  the  name  of  the  muscle.  The  dotted  lines  represent  the 
false  images  belonging  to  the  affected  eye,  the  continuous  lines  the 
true  images  belonging  to  the  unaffected  eye. 

In  the  case  of  the  recti,  the  false  images  enclose  a  lozenge-shaped 
space  in  the  centre  of  the  figure,  whereas  the  false  images  correspond- 
ing with  the  obliques  will  be  found  in  the  outer  portions.  It  will  also 
be  noted  that  the  dotted  lines  extend  upwards  and  downwards  be- 
yond the  others,  indicating  respectively  that  the  false  images  are 
higher  or  lower  than  the  true  ones.     Another  fact  which  the  diagram 


LIO 


LS.R^RSR 


RIO 


OhUqae 


LSO. 


Rail 


LIR    X'rIR, 


,  Oblique 


RSO 


Left  Eye  RiglitEye 


Fig.   194. — Diagram  of  the  diplopia  due  to  paralysis  of  any  one 
of  the  elevator  or  depressor  muscles. ^ 

indicates  is  that,  in  the  case  of  the  muscles  represented  in  the  upper 
halves  of  the  figures,  the  diplopia  occurs  in  the  ufiper  part  of  the 
field  of  fixation,  or,  in  other  words,  in  upward  movements  of  the 
eyes.     A  similar  rule  holds  good  with  regard  to  the  lower  halves. 

The  method  of  using  the  diagrams  will  be  better  understood  by 
taking  a  particular  muscle  as  an  example.     Suppose,  for  instance. 


1  Fig.  194  is  a  combination  of  two  mnemonic  diagrams  which  appeared 
in  previous  editions  of  this  book.  They  have  been  so  combined  in  order 
to  correspond  exactly  with  Fig.  193,  ilhistrating  the  action  of  the  muscles. 
A  comparison  of  Figs.  188,  193,  and  194  will  reveal  that  they  are  practically 
the  same,  and  that  Fig.  1  93,  which  shows  the  action  of  the  muscles,  will 
consequently  also  represent  tlie  diplopia  characteristic  of  each  muscle, 
and  also  the  torsion  which  occurs  in  extreme  obliqvie  positions.     (L,  W.) 


486  DISEASES   OF    THE   EYE.  [chap.  xvii. 

that  we  wish  to  know  what  kind  of  diplopia  results  from  paralysis 
of  the  left  inferior  rectus,  it  is  simply  necessary  to  look  at  the  left 
inferior  part  of  the  centre  of  the  figure  (recti),  which  gives  the  dip- 
lopia. If  we  analyse  this  we  find  (1)  that  the  diplopia  is  crossed, 
for  the  false  image  corresponding  with  the  left  eye  is  on  the  right  of 
the  true  image — i.e.  the  right  image  corresponds  with  the  left  eye  ; 
(2)  that  the  false  image  has  its  wjoper  end  inclined  towards  the  true 
one  ;  (3)  that  the  false  image  is  lower  than  the  true  one,  for  the 
dotted  line  extends  lower  than  the  other  one  ;  (4)  that  the  diplopia 
occurs  in  downward  movements  of  the  eyes,  for  it  is  in  the  lower 
half  of  the  diagram  that  the  false  image  lies. 

The  same  method  applies  to  the  other  recti ;  the  diplopia  for 
the  right  upper  rectus  is  found  in  the  right  upper  quadrant,  and 
so  on  for  the  rest. 

The  diplopia  corresponding  with  one  of  the  obliques  will  be  found 
in  the  outer  part  of  the  figure  on  the  same  side  as  the  muscle,  and 
for  the  same  reason  as  in  Fig.  193  the  superior  oblique  will  be  below 
and  vice  versa.  L.S.O.  gives  the  diplopia  for  the  left  superior 
oblique. 

The  figures  can  be  called  to  mind  either  as  consisting  of  the  four 
recti  in  the  centre  and  the  four  obliques  at  the  outsides,  or  as  being 
made  up  of  an  x  for  each  eye,  with  the  two  recti  on  the  inside 
and  the  two  obliques  on  the  outside. 

This  is  an  extremely  simple  method.  By  bearing  the  figures 
in  mind  it  is  possible  to  tell  immediately  what  kind  of  diplopia 
would  result  from  paralysis  of  any  one  of  these  muscles,  and  con- 
versely, given  the  diplopia,  to  determine  to  which  muscle  it  is  due. 
Fig.  194  may  be  used  alone,  without  reference  to  the  action  of  the 
muscles,  when  there  is  little  time  for  thought. 

*  Some  of  the  paralyses  seem  to  resemble  one  another  very 
closely  in  the  form  of  the  diplopia  produced  ;  for  example,  para- 
lysis of  the  left  superior  oblique,  and  of  the  right  inferior  rectus, 
in  which  the  diplopia  occurs  in  both  cases  below  the  horizontal 
plane,  and  the  false  image  is  to  the  left  of,  and  lower  than,  the 
true  one,  and  inclined  towards  it.  The  distinction  is  made  by 
observing  that  the  false  image  belongs  to  the  left  eye  (homonymous 
diplopia)  in  the  case  of  the  oblique  muscle,  and  to  the  right  eye 
crossed  diplopia)  in  the  case  of  the  rectus.  Figs.  195  and  196 
explain  this. 


CHAP.    XVII.] 


THE    ORBITAL   MUSCLES. 


487 


Again,  as  Duane  points  out,  the  position  of  the  eye  in  which 
the  vertical  element  of  the  diplopia  is  at  its  maximum  is  of  the 
greatest  importance  for  the  diagnosis  of  the  muscle  at  fault,  in  the 
case  of  the  elevators  and  depressors.     In  the  above  cases,  for  instance, 


R 


.4^' 


L  //  - 


Fig.   195. 


e 


R 


^' 


Fici.   196. 


Fig.  195. — Paralysis  of  left  sup.  oblique.  Homonymous  diplopia, 
R,  image  of  right  eye.     L,  image  of  left  eye. 

Fig.  196. — Paralysis  of  right  inferior  rectus.  Crossed  diplopia.  R, 
image  of  right  eye.     L,  image  of  left  eye. 

the  vertical  separation  of  the  images  in  paralysis  of  the  left  superior 
oblique  will  be  at  its  greatest  when  an  attempt  is  made  to  turn  the 
eye  downwards  and  inwards  ;  and  the  maximum  deviation  in  this 
respect,  in  the  case  of  the  left  inferior  rectus,  will  be  found  when  the 
eye  looks  downwards  and  outwards  (p.  467). 

In  case  the  diplopia  does  not  correspond  with  any  of  the  recognised 
forms  characteristic  of  paralysis  of  any  single  muscle,  the  condition  becomes 
complicated,  and  the  solution  of  the  question  as  to  which  muscles  are  at 
fault  is  frequently  impossible,  but  there  are  two  very  simple  causes  through 


\\ 


^:>« 


Fig.   197. 


Fig.   198. 


Fig.   199. 


which  the  nature  of  the  diplopia  may  be  changed  and  which  should  be 
mentioned.  In  the  first  place  the  patient  may  fix  with  the  paralysed  eye, 
and  when  this  occurs  the  image  belonging  to  it  will  seem  to  him  to  be  in 
a  correct  position,  and  that  of  the  other  eye  will  be  apparently  displaced. 


488  DISEASES    OF    THE   EYE.  [chap.  xvii. 

It  is  merely  necessary  to  suppose  that  the  diagram  of  the  diplopia  in  the 
particular  case  is  rotated,  so  that  the  image  belonging  to  the  paralysed 
eye  becomes  vertical.  For  example,  Fig.  197  in  this  case  would  be 
converted  into  Fig.  198. 

Again,  if  paralysis  of  an  elevator  or  depressor  occurs  in  a  patient 
with  a  latent  horizontal  deviation,  either  convergence  or  divergence,  a 
crossed  or  homonymous  diplopia  may  be  reversed,  on  account  of  the 
latent  deviation  becoming  manifest  in  consequence  of  the  impossibility 
of  fusing  the  images,  and  thus  Fig.  197  would  be  changed  to  Fig.  198. 

Measurement  of  the  degree  of  paralysis  is  useful  for  prognosis, 
and  also  for  estimating  the  progress  of  the  case.  It  may  be  measured 
by  noting  the  amount  of  separation  of  the  double  images.  Mad- 
dox's  rod-test  with  scale  is  very  suitable  for  this,  or  the  prism  required 
to  correct  the  diplopia  may  be  noted,  the  deviation  being  equal  to 
half  the  angle  of  the  prism.  Another  method  consists  in  measuring 
the  mobility  of  the  eye,  in  the  direction  of  the  paralysed  muscle, 
with  the  perimeter. 

The  Causes  of  Paralyses  of  Orbital  Muscles. 

Loss  of  power  of  one  or  more  of  the  muscles  of  the  eyeball  is, 
of  course,  always  to  be  regarded  as  a  symptom,  not  as  a  disease. 

This  loss  of  power  may  be  due  to  lesions  in  several  different  situa- 
tions, namely  . — (1)  Lesions  situated  in  the  orbit.  (2)  Basic  lesions 
— i.e.  lesions  situated  at  the  sphenoidal  fissure  and  those  at  the  base 
of  the  skull,  between  the  sphenoidal  fissure  and  the  pons.  (3)  Pon- 
tine lesions,  which  may  be  Fascicular — i.e.  involving  the  ocular 
nerve  fibres  in  the  substance  of  the  pons — or  Nuclear — i.e.  only 
attacking  the  nuclei  of  the  nerves  in  the  aqueduct  of  Sylvius  and 
floor  of  the  fourth  ventricle.  (4)  Cerebral  lesions — i.e.  supra-nuclear, 
in  the  internal  capsule,  corona  radiata,  or  cortex.  These  four 
classes  differ  considerably  in  their  clinical  aspect,  in  their  patho- 
logical causes,  and  in  their  significance  for  the  well-being  of  the 
patient. 

The  first  class — loss  of  power  due  to  orbital  lesions — will  be 
considered  in  the  chapter  on  Diseases  of  the  Orbit. 

The  second  class — those  due  to  basic  lesions — provides  by  far 
the  largest  number  of  cases  of  paralyses  of  the  orbital  muscles. 
Basic  paralyses  are  chiefly  of  rheumatic  or  syphilitic  nature. 

Rheumatic  paralysis,  to  which  the  external  rectus  is  specially 
prone,  will  be  noted  if  tliere  be  symptoms  of  general  rheumatism,  or 


CHAP,  xvii.]  THE    ORBITAL    MUSCLES.  489 

if  there  be  a  history  of  exposure  to  cold  or  wet  immediately  preceding 
the  attack.  Some  of  these  so-called  rheumatic  cases  are  probably 
of  toxic  origin. 

Syphilis  will  be  suggested  by  a  specific  history,  and  rendered 
certain  by  a  positive  Wasserman  reaction.  Peripheral  paralyses  of 
the  orbital  muscles  due  to  syphilis  are  amongst  the  later  symptoms  of 
the  disease,  and  may  depend  on  exostoses  or  gummata  at  the  base 
of  the  skull,  or  to  syphilitic  neoplasms,  or  meningitis,  in  the  course 
of  the  nerve.  The  third  nerve  seems  to  be  particularly  liable  to  be 
attacked  by  a  solitary  gumma  at  the  base  of  the  skull,  especially  at 
the  sphenoidal  fissure,  ptosis  being  commonly  the  first  symptom. 

Other  causes  are  neoplastic  growths,  meningitis,  purulent  otitis, 
aneurisms,  etc.  In  arterio-venous  aneurism  in  the  cavernous 
sinus,  the  sixth  nerve  is  most  frequently  involved. 

Fracture  of  the  base  of  the  skull  may  be  indicated  by  a  fourth 
nerve  paralysis,  as  the  only  symptom,  due  to  injury  of  the  nerve  as 
it  passes  over  the  apex  of  the  petrous  portion  of  the  temporal  bone, 
but  paralysis  of  the  sixth  nerve  is  more  common  with  this  lesion 
and  may  be  bilateral. 

In  the  diagnosis  of  a  basal  lesion  as  the  cause  of  the  paralysis, 
the  gradual  and  successive  involvement  of  different  cranial  nerves 
according  to  their  anatomical  position,  or  even  independently  of 
their  anatomical  arrangement,  is  suggestive  ;  as  for  example  facial 
neuralgia,  or  facial  anaesthesia  occurring  along  with  paralysis  of 
ocular  muscles.  And  the  presence  of  atrophy  of  one  or  of  both  optic 
nerves,  or  of  a  bi- temporal  hemianopsia,  would  furnish  conclusive 
evidence  of  the  basal  origin  of  such  paralysis. 

Prognosis. — In  peripheral  paralyses  recovery  is  very  frequent, 
much,  however,  depending  on  the  nature  of  the  lesion.  In  cases 
where  a  cure  is  not  effected,  the  diplopia  eventually  becomes  less 
troublesome  and  the  antagonist  muscle  often  contracted,  the  eye 
being  then  rotated  permanently  and  excessively  in  the  corresponding 
direction.  In  cases  of  old  standing,  a  permanent  contraction  of  the 
muscles  of  the  neck  may  be  brought  about,  from  the  inclination  of 
the  head  which  the  diplopia  has  obliged  the  patient  to  adopt- 

Treatment. — In  these  cases  the  medical  treatment  consists  in 
drugs  suitable  to  the  fundamental  disease  (rheumatism,  syphilis, 
etc.).  Local  depletion  at  the  temple  by  the  artificial  leech  in  the 
early  stages,  and  galvanism  later  on,  may  be  employed  with  advan- 


400  DISEASES   OF    THE    EYE.  [chap.  xvii. 

tage.  The  most  common  method  of  applying  galvanism  is  through 
the  closed  lid  ;  but  it  is  probable  that  the  episcleral  method — i.e. 
with  the  electrode  placed  directly  over  the  muscle — is  more  effectual. 
A  good  method  is  for  the  surgeon  to  take  one  rheophore,  well  wetted, 
in  one  hand,  and,  having  secured  good  contact  with  the  skin  of  the 
palm,  the  index  finger  is  applied  to  the  patient's  globe  in  the  situa- 
tion of  the  various  external  muscles  of  the  eye.  The  finger  is 
covered  with  a  single  thickness  of  well -moistened  muslin,  and  the 
conjunctiva  should  be  previously  rendered  insensitive  by  cocaine. 
The  other  rheophore,  a  moistened  plate,  is  placed  on  the  nape  of 
the  patient's  neck.  The  strength  of  the  current  advised  is  from 
1"5  to  2  milliamperes,  and  the  alternate  application  and  lifting  of 
the  finger,  by  closing  and  opening  the  circuit,  gives  rise  to  a  feeling 
of  a  slight  electric  shock  in  the  terminal  point  of  the  finger.  The 
operator  should  first  test  the  strength  of  the  current  upon  the 
patient's  cheek.  The  point  of  the  finger  thus  employed  acts  as  a 
sentient  rheophore,  and  can  be  applied  with  nicety  and  delicacy 
to  various  parts  of  the  eye,  the  operator  being  constantly  aware, 
by  the  feeling  in  his  finger,  of  the  strength  of  the  current  employed. 

Passive  orthoptic  treatment  occasionally  gives  a  rapid  and 
brilliant  result,  while,  again,  it  is  useless.  It  is  performed  as  follows  : 
— The  conjunctiva  at  the  corneo-scleral  margin,  near  the  insertion 
of  the  paralysed  muscle,  is  seized  with  a  forceps,  and  the  eyeball  is 
drawn  in  the  direction  of  the  muscle,  and  as  far  as  possible  beyond 
its  ordinary  limit  of  contraction,  and  back  again.  These  move- 
ments are  continued  for  about  a  minute  once  a  day,  cocaine 
being    used. 

Prismatic  glasses  may  be  used,  either  to  eliminate  the  diplopia, 
or  to  excite  the  weak  muscle  to  exert  itself.  In  the  former  case,  the 
glass  selected  must  completely  neutralise  the  diplopia  ;  but,  as  it 
can  do  so  only  for  one  position  of  the  eyes,  prisms  are  rarely  employed 
in  this  way.  In  the  latter  case,  a  prism  slightly  weaker  than  that 
sufficient  to  completely  neutralise  the  diplopia  is  selected,  in  order 
that,  with  a  little  effort,  the  weak  muscle  may  be  enabled  to  bring 
about  single  vision,  and,  this  effort  having  been  successfully  main- 
tained for  some  days,  a  still  weaker  prism  is  then  prescribed,  and  so 
on.  Since  more  than  a  4°  prism  in  each  eye  can  seldom  be  worn, 
and  the  diplopia  varies  in  different  positions,  the  use  of  prisms  here 
is  very  limited. 


CHAP.   XVII.]  THE    ORBITAL   MUSCLES.  491 

It  is  important  for  the  patient's  comfort  while  awaiting  his  cure, 
unless  a  cure  by  prisms  as  above  described  is  being  attempted,  that 
the  affected  eye  should  be  covered,  so  that  the  distressing  double 
vision  may  be  obviated ;  or,  better  still,  if  it  be  a  lateral  muscle 
that  is  paralysed,  by  excluding  only  the  half  of  the  field  of  the 
defective  eye  in  which  diplopia  occurs,  it  can  take  part  in  the  act 
of  vision  in  the  remaining  half  of  the  field. 

Surgical  treatment  is  justifiable  only  when,  after  six  months  or 
a  year,  other  means  have  failed  to  restore  muscular  equilibrium. 
Advancement  of  the  paralysed  muscle  with,  if  necessary,  tenotomy 
of  the  antagonist  is  indicated.  Tenotomy  of  the  associated  muscle 
of  the  other  eye  is  sometimes  performed  to  establish  equilibrium,  but 
in  this  case  a  compensatory  movement  of  the  head  must  take  place. 
This  surgical  treatment  applied  to  the  internal  and  external  rectus 
sometimes  gives  satisfactory  results  ;  but  in  the  cases  of  the  superior 
and  inferior  recti  it  is  less  useful.  The  oblique  muscles  should  not 
be  operated  on,  but  tenotomy  of  the  associated  muscle  in  the  opposite 
eye  (in  the  case  of  the  K.  sup.  oblique,  the  L.  inf.  rectus)  may  give 
relief. 

A  peculiar  and  rare  form  of  peripheral  or  basal  paralysis  is  Inter- 
mitting Paralysis  of  the  Third  Nerve  of  one  Eye,  sometimes  inaccurately 
termed  Ophthalmoplegic  Migraine.  The  patients  are  generally  children 
or  young  adults,  who  usually  svxffer,  at  long  or  short  intervals,  measured 
it  may  be  by  months  or  years,  from  attacks  of  headache  on  the  side  corre- 
sponding with  the  paralysed  eye,  and  frequently  from  vomiting.  This 
'  bilious  attack  '  is  attended,  or  soon  followed,  by  paralysis  of  one  or 
more  branches  of  the  third  nerve.  The  paralysis  may  be  complete  or 
partial,  and  the  attack  varies  in  its  duration  from  a  few  days  to  a  few 
months.  In  rare  instances  the  sixth  nerve  has  been  paralysed.  Excessive 
salivation,  perspiration,  or  discharge  from  the  nose  occurs  in  a  few  cases. 
Some  cases  are  purely  periodical — i.e.  in  the  intervals  between  the 
attacks  of  paralysis  all  the  muscles  supplied  by  the  third  nerve  act  in  a 
completely  normal  manner ;  while  in  other  cases  these  muscles,  or  some 
of  them,  do  not  completely  recover  their  functions  in  the  intervals.  There 
are  no  visual  symptoms  such  as  occur  in  migraine,  neither  do  the  patients, 
as  in  migraine,  belong  chiefly  to  the  intellectual  classes.  We  are  as  yet 
quite  in  the  dark  as  to  the  cause  of  these  periodical  paralyses  of  the  third 
nerve.  It  is  possible  that  the  purely  periodical  cases  are  of  a  functional 
nature — reflex,  or  due  to  recurrent  toxsemia,  possibly  of  gastro-intestinal 
origin — and  that  the  periodically  exacerbating  cases  alone  are  due  to  a 
lesion  of  the  root  of  the  nerve,  of  an  undefined  kind,  at  the  base  of  the 
skull.  In  three  cases  of  the  latter  kind,  in  which  an  autopsy  was  made, 
there  was  disease  of  the  trunk  of  the  nerve  at  the  base  of  the  skull. 


4!)2  DISEASES    OF    THE   EYE.  [chap.   xvii. 

In  intermitting  paralysis  the  Prognosis  of  the  purely  periodical  form 
is  favourable,  inasmuch  as  the  attacks  in  the  course  of  time  become  fewer 
and  less  severe,  until,  finally,  they  entirely  cease.  In  the  exacerbating 
form  the  prognosis  for  complete  recovery  is  less  favourable.  Out  of 
twenty-six  cases  collected  by  Darquier  only  one  patient  died  and  from  a 
cerebral  cause. 

In  view  of  the  obscurity  which  still  surrounds  the  causation  of  these 
intermitting  paralyses  their  Treatment  must  consist,  in  each  case,  in  the 
relief  of  any  general  dyscrasia  or  concomitant  symptoms  which  may  be 
present.  Purgatives  and  drinking  of  hot  water  have  proved  of  some  service 
in  some  casps. 

Paralysis  of  the  Third  Nerve  with  Cyclical  Spasm. — This  is  also  a 
rare  affection,  the  cause  of  which  is  unknown,  but  it  may  be  described 
here.  In  these  cases  there  is  partial  paralysis  of  the  third  nerve,  which 
is  usually  congenital,  and  at  intervals  of  about  a  minute  the  pupil  contracts, 
the  upper  lid  becomes  elevated  and  spasm  of  accommodation  occurs, 
associated,  it  may  be,  with  convergence  ;  after  a  short  interval  of  a  few 
seconds  or  a  minute  the  paralytic  condition  again  returns. 

The  third  class  of  paralyses  of  orbital  muscles  above  enumerated 
— those  due  to  lesions  of  the  nuclei  of  the  orbital  muscles  in  the 
aqueduct  of  Sylvius  and  floor  of  the  fourth  ventricle — are  known  by 
the  term 

*  Ophthalmoplegia  Externa,  and  also  as  Nuclear  Paralysis.— The 
first  of  these  terms  was  originally  employed  to  denote  those  remark- 
able cases  in  which  all,  or  nearly  all,  of  the  orbital  muscles  of -both 
eyes  are  paralysed,  while  the  intra-ocular  muscles  often  remain 
intact.  There  can  be  no  doubt,  however,  that  these  cases  do  not 
differ  in  their  nature  from  many  of  those  in  which,  in  one  eye,  several 
orbital  muscles  supplied  by  different  nerves — e.g.  third  and  fourth — 
are  wholly  or  partially  paralysed  ;  or  where  all  the  orbital  muscles 
in  one  eye  are  wholly  or  partially  paralysed  ;  or  where  in  each  eye 
muscles  supplied  by  the  same  nerve — e.g.  both  sixth  nerves — are 
wholly  or  partially  paralysed  ;  for  such  cases  are  often  mild  forms 
of  the  disease,  or  else  stages  in  its  development.  At  one  time  it 
was  considered  essential  for  the  diagnosis,  that  the  intra-ocular 
muscles  should  retain  their  functions,  but  cases  occur  in  which  the 
sphincter  iridis  and  ciliary  muscle  are  paralysed. 

When  the  latter  muscles  alone  are  paralysed,  the  condition  is 
called  Ophthalmoplegia  Interna.  AVhen  both  they  and  groups  of 
orbital  muscles  are  paralysed  the  terms  Ophthalmoplegia  Interna  et 
Externa,  or  Ophtlialmoplegia  I^niversa,  are  employed. 

The  term  Nuclear  Paralysis  indicates  any  orbital  paralysis  due 


CHAP.   xviT.]  THE    nnniTAL    MUSCLES^.  403 


to  a  lesion  of  the  nuclei  of  the  orbital  nerves  in  the  pons,  and  ophthal- 
moplegia externa  often  conies  within  this  category. 

Ptosis,  even  in  cases  of  complete  binocular  ophthalmoplegia 
externa,  is  often  incomplete,  and  it  is  remarkable  that  in  some 
chronic  cases,  without  any  improvement  in  the  condition  itself,  the 
diplopia,  which  was  at  first  present,  quite  disappears. 

Occurrence  and  Progress. — The  condition  may  be  congenital,  or 
may  make  its  appearance  soon  after  birth,  and  may  remain  perma- 
nently without  becoming  complicated  with  any  further  disturbance. 
Congenital  ptosis,  which  is  frequently  combined  with  loss  of  power 
in  the  superior  rectus,  and  is  usually  binocular,  is  of  this  nature.  But 
Nuclear  Paralysis  is  more  commonly  seen  as  an  acquired  condition 
in  childhood,  or  in  adult  life,  either  in  an  acute  or  chronic  form. 
Marked  cerebral  lethargy  is  often  seen  with  both  forms,  and  the 
tendon  reflexes  may  be  defective. 

Acute  Nuclear  Paralysis  is  due  either  to  an  acute  inflam- 
matory process  in  the  nuclei — comparable  to  the  process  which 
produces  polio-myelitis  anterior  acuta,  and  hence  it  is  called 
by  Byrom  Bramwell  polio-myelitis  acuta — or  to  hsemorrhagic 
lesions. 

The  acute  inflammatory  cases  are  apt  to  have  a  sudden  onset, 
attended  with  fever,  headache,  vomiting,  and  convulsions,  which 
may  subside  after  a  few  days,  leaving  only  the  ophthalmoplegia 
behind  ;  and  this,  too,  after  a  lengthened  period,  may  undergo  cure, 
partial  or  complete.  Transient  paralysis  of  conjugate  movements 
often  occur  at  the  beginning  of  the  attack.  The  intra-ocular  muscles 
and  levator  palpebrse  are  often  spared.  Sometimes  these  attacks 
are  complicated  with  paralysis  of  the  facial  nerve,  or  the  diseased 
process  may  extend  to  the  spinal  cord,  and  the  symptoms  of  acute 
polio-myelitis  become  developed  ;  or,  again,  acute  bulbar  paralysis 
may  come  on. 

Acute  peripheral  neuritis  of  the  ocular  nerves,  which  is  sometimes 
seen  in  cases  of  alcoholic  poisoning,  may  be  mistaken  for  acute 
nuclear  palsy.  The  symptoms  of  the  two  states  are  the  same,  except 
that  in  the  case  of  peripheral  neuritis  there  are  no  head  symptoms 
at  the  commencement. 

The  onset  of  acute  heemorrhagic  ophthalmoplegia  is  sudden,  but 
is  unattended  by  headache,  vomiting,  or  convulsions.  It  takes 
different  courses.     Sometimes  it  is  rapidly  fatal ;    again,  it  goes  on 


494  DISEASES   OF    THE   EYE.  [chap.   xvit. 


to  softeuiug  of  the  nuclei,  uud  becomes  chrouic  ;  while,  again,  it 
undergoes  a  slow  cure. 

It  is  extremely  probable  that  to  this  lui'morrhagic  class  some  of 
the  cases  of  paralysis  of  orbital  muscles  belong,  which  occasionally 
f(jllow  on  an  attack  of  diphtheritic  sore-throat.  These  paralyses 
appear  in  from  one  to  six  weeks  after  the  outbreak  of  the  primary 
affection.  The  latter  need  not  have  been  of  a  severe  kind  ;  indeed, 
sometimes,  patients  are  unaware  that  they  have  had  a  sore-throat. 
These  diphtheritic  paralyses  always  recover  in  the  course  of  some 
weeks. 

In  diabetes,  paralyses  of  orbital  muscles  are  not  very  uncommon, 
and  are  probably  to  be  classed  as  nuclear.  The  same  may  be  said 
of  orbital  paralysis  in  lead  poisoning,  influenza,  syphilis  sometimes, 
and  in  Gerlier's  disease  (Vertige  Paralysant).  Other  causes  are  • — 
cold,  poisoning  by  nicotine,  sulphuric  acid,  carbonic  oxide,  and 
ptomaines. 

The  Prognosis  in  all  these  instances  is  favourable. 

Chronic  Nuclear  Paralysis  (Chronic  Polio-encephalitis  Superior, 
of  Wernicke)  is  much  more  common  than  the  acute  form.  It  de- 
pends on  a  degenerative  atrophy  of  the  nerve  nuclei,  analogous  to 
that  which  occurs  in  progressive  muscular  atrophy  and  in  chronic 
bulbar  paralysis.  •  The  onset  is  gradual,  the  loss  of  power  in 
the  muscles  being  at  first  very  slight,  but  ultimately  complete 
paralysis  of  the  affected  muscles  results.  There  is  no  fever,  nor  any 
cerebral  symptom.  The  condition  may  become  associated  with 
chronic  bulbar  paralysis,  with  progressive  muscular  atrophy,  or  with 
locomotor  ataxy  ;  but  this  is  not  so  liable  to  occur  in  infants  as 
in  adults. 

In  some  cases  there  may  be  partial  paralysis  of  the  orbicularis 
palpebrarum,  which,  according  to  Mendel,  is  innervated  from  the 
third  nerve  nucleus  through  the  facial  nerve,  along  with  other 
muscles  of  the  oculo-facial  group  (frontalis  and  corrugator  supercilii). 

Coarse  lesions,  especially  tumours  of  the  pons,  or  of  its  neigh- 
bourhood which  press  on  it,  may  produce  orbital  paralyses  closely 
simulating  those  due  to  nuclear  lesions,  as  we  have  recently  observed 
in  a  case  of  tumour  of  the  pituitary  body.  But  here  the  paralysis 
is  only  one  of  the  symptoms  in  the  case,  which  are  likely  to  include 
headache,  vomiting,  optic  neuritis,  and,  according  to  the  situation 
of  the  lesion,  hemianopsia,  hemiplegia,  etc.     Softenings,  patches  of 


CHAP.  xviT.]  THE    ORBITAL    MUSCLES.  495 

disseminated  sclerosis,  and  internal  liydruceplialus  witk  uver-dis- 
tension  of  the  aqueduct  of  Sylvius,  are  other  lesions  which  may  give 
rise  to  similar  orbital  paralyses,  but  which  cannot  be  regarded  as 
true  nuclear  ophthalmoplegia.  The  mode  of  onset,  and  the  con- 
comitant symptoms,  of  each  case  must  serve  as  our  guides  in  arriving 
at  a  diagnosis,  which  will  sometimes  be  difficult  enough. 

According  to  Bernheimer,  the  diagnosis  of  a  nuclear  paralysis 
of  the  muscles  must  take  into  account  the  accompanying  symptoms, 
etiology,  course  of  the  disease,  etc.,  for  the  grouping  of  the  affected 
muscles,  whether  intra-  or  extra-ocular,  functionally  associated  or 
otherwise,  is  not  sufficient  in  itself  to  warrant  the  assumption  of  a 
nuclear  origin  of  the  affection. 

Conjugate  Lateral  Paralysis  of  the  eyes  is  a  symptom  which  may 
be  caused  by  a  lesion  in  the  pons.  It  has  been  generally  held  that 
the  voluntary  motor  impulses,  coming  down  from  the  cortex  to 
produce  associated  lateral  motions  of  the  eyeballs — i.e.  action  of 
the  external  rectus  of  one  eye,  along  with  action  of  the  internal 
rectus  of  the  other  eye — first  reach  the  nucleus  of  the  sixth  nerve, 
and  then  pass  on  under  the  corpora  quadrigemina,  through  the 
posterior  longitudinal  bands,  the  neurons  of  which  connect  the 
sixth  nucleus  with  the  third  nucleus  of  the  same  side  and  so 
through  crossed  third  nerve  fibres  finally  reach  the  internal  rectus 
of  the  opposite  side.  The  sixth  pair  of  one  side  supplies  in 
this  way  the  external  rectus  of  its  own  side,  and  also  influences 
the  internal  rectus  of  the  opposite  side  ;  and  it  is  quite  probable 
that  similar  connections  may  exist  in  the  nerve  supply  of  other 
orbital  muscles.  Hence  a  lesion  at,  let  us  say,  the  left  sixth  nerve 
nucleus  would  paralyse  the  conjugate  lateral  motions  of  the  eyes 
towards  the  left  side  ;  and  there  would  in  consequence  be  conjugate 
lateral  deviation  of  the  eyes  towards  the  right — the  eyes  looking 
away  from  the  lesion.  (See  also  p.  499.)  In  conjugate  paralysis 
or  deviation,  whether  due  to  a  pontine  lesion,  or,  as  will  be  described 
in  a  later  paragraph,  to  a  cerebral  lesion,  the  combined  action  of 
the  internal  recti  for  the  purpose  of  convergence  of  the  eyes  is 
retained. 

According  to  a  more  recent  view  the  crossed  fibres  for  innerva- 
tion of  the  internal  rectus  in  conjugate  movements  do  not  come 
from  the  contralateral  sixth  nerve  nucleus,  but  from  the  contra- 
lateral third  nerve  nucleus,  each  third  nerve  therefore  containing 


liui  DISEASES    OF    THE    EYE.  [chap.   xvtt. 

direct  and  crossed  fibres,  and  the  posterior  longitudinal  bands 
contain  ascending  vestibulo-ocular  fibres  which  pass  up  close  to  the 
sixth  nucleus,  a  lesion  of  which  will  not  cause  conjugate  paralysis 
unless  it  involve  also  these  vestibulo-ocular  fibres.  The  sixth 
nerve  contains  direct  fibres  only. 

Paralysis  of  the  orbital  muscles  from  nuclear  disease,  apart 
from  the  primary  conditions  already  described,  may  occur  in 
Locomotor  Ataxy,  Disseminated  Sclerosis,  General  Paralysis, 
Chronic  Alcoholism,  and  more  rarely  in  Exophthalmic  Goitre  and 
Severe  Multiple  Neuritis. 

*  Fascicular  Paralyses  are  mainly  distinguished  by  the  presence 
of  other  symptoms  due  to  involvement  of  neighbouring  structures. 
They  are  rarely  symmetrical.  Vertigo  is  common  with  fascicular 
third-nerve  paralysis,  owing  to  implication  of  the  red  nucleus  in 
the  tegmentum  which  is  connected  with  the  superior  peduncle  of 
the  cerebellum.  Bernheimer  thinks  that  fascicular  and  nuclear 
paralysis  are  not  separable  clinically. 

In  Myasthenia  Gravis  the  symptoms  include  some  which  are  due 
to  derangement  in  the  power  of  orbital  muscles.  It  occurs  mostly  in 
young  people  the  subjects  of  malnutrition.  Ptosis  is  a  common  symptom  ; 
it  is  usually  bilateral  and  more  marked  on  one  side  than  on  the  other. 
It  may  be  constant,  or  it  may  only  be  present  towards  the  latter  end  of 
the  day,  or  if  the  patient  looks  up  for  any  length  of  time,  when  the  lids 
gradually  fall.  Owing  to  weakness  of  the  occipito-frontalis  muscles, 
their  compensatory  over-action,  so  comiaion  in  other  forms  of  ptosis,  does 
not  occur  except  in  the  incipient  stage.  Weakness  of  the  orbital  muscles 
with  resulting  diplopia  is  often  present.  Sometimes  one  muscle  is  more 
affected  than  others,  sometimes  there  is  a  general  paresis  affecting  all  the 
orbital  muscles,  while  in  some  cases  complete  and  persistent  ophthal- 
moplegia externa  is  present.  An  alteration  in  the  relative  position  of 
the  two  images  is  a  striking  feature.  In  some  cases  irregular  nystagmoid 
movements  are  induced  upon  conjugate  lateral  motion  of  the  eyes.  The 
ocular  muscles,  as  is  the  case  with  other  voluntary  muscles,  become  readily 
fatigued,  the  patients  complaining  that  after  reading  a  few  lines  the  words 
and  letters  run  into  each  other.  Pupil  changes  are  exceptional,  but  the 
pupils  are  sometimes  unequal.  In  Buzzard's  case,  after  prolonged 
convergence,  the  pupils  showed  a  tendency  to  oscillatory  movements.  The 
power  of  accommodation  does  not  become  fatigued. 

The  general  features  of  the  disease  are  : — Weakness  of  some  or  all  of 
the  voluntary  muscles  of  the  body,  which  may  amount  to  complete 
paralysis.  After  a  long  rest — e.g.  on  awaking  in  the  morning — they  may 
respond  normally  to  the  will,  but  become  rapidly  exhausted  after  a  little 
use.  The  affected  muscles  often  exhibit  the  myasthenic  reaction,  becom- 
ing exhausted  by  faradic  stimulation.     The  entire  system   of  voluntary 


CHAP.   XVII.]  THE    ORBITAL    MUSCLED.  407 


muscles  may  be  affected,  but  tiiose  muscles  are  most  apt  to  be  implicated 
which  normally  act  most  continuously  or  frequently,  such  as  the  cervical 
muscles  and  the  extrinsic  muscles  of  the  eyeball.  The  symptoms  fluctuate 
from  day  to  day,  or  from  month  to  month,  and  may  even  disappear  for 
months  or  even  years,  and  then  reappear.  There  are  no  sensory  symptoms. 
Death  occurs  in  a  large  proportion  of  the  cases,  but  no  structural  changes 
have  been  found  to  account  for  the  symptoms. 

*  Cerebral  Paralyses  of  Orbital  Muscles  form  the  fourth  and  last 
of  the  classes  enumerated.  They  include  all  the  orbital  paralyses 
due  to  lesions  above  the  nuclei — i.e.  in  the  cortex,  corona  radiata, 
or  internal  capsule.  They  are  usually  associated  with  other  symp- 
toms which  aid  us  in  localising,  more  or  less  accurately,  the  lesions 
which  cause  them.  These  paralyses  are  always  physiological, 
associated,  or  conjugate,  as  they  are  variously  and  with  equal  cor- 
rectness termed — they  are,  in  short,  paralyses  of  motion  rather 
than  of  muscles. 

Conjugate  lateral  paralysis — loss  of  power  of  motion  of  the  eyes 
to  one  side  or  to  the  other,  while  the  power  of  convergence  of  the 
optic  axes  is  retained — is  by  far  the  most  common  form  of  this 
symptom.  We  do  not  as  yet  know  where  the  cortical  centre  for 
the  associated  lateral  motions  of  the  eyes  is  situated.^  But  even 
if  we  did  know  its  position,  it  is  not  likely  that  much  would  be  gained 
so  far  as  clinical  localisation  of  the  cerebral  lesion  is  concerned  ; 
for  this  centre,  wherever  it  may  be,  is  extremely  sensitive,  and  is 
apt  to  be  thrown  out  of  gear  by  lesions  of  many  different  parts  of 
the  cortex.  Conjugate  deviation  is,  in  short,  very  apt  to  be  a  dis- 
tant symptom,  especially  in  cerebral  haemorrhage,  when  it  is  often 
accompanied  by  a  rotation  of  the  head  in  the  same  direction,  and 
lasts  only  a  short  time.  Moreover,  it  is  thought  that,  when  this 
centre  may  happen  to  be  actually  involved  in  the  lesion,  its  function, 
being  largely  bilateral,  is  rapidly  taken  up  by  the  opposite  hemi- 

1  This  centre  has  been  placed  by  various  avithors  in  the  inferior  parietal 
lobule  (Wernicke,  Henschen,  Munk,  etc.),  and  in  the  second  frontal  con- 
volution (Ferrier,  Horsley,  and  Beevor).  Stimulation  of  the  centres 
of  vision  in  the  occipital  lobe  has  also  been  found  to  produce  conjugate 
movements  (Schsefer,  Munk),  and  these  have  been  regarded  as  reflex  by 
some  ;  but  Knies  holds  that  the  visual  centre  contains  the  motor  centre 
for  the  eye-muscles  as  well.  Moreover,  it  is  stated  that  the  visual  cortex 
contains  motor  pyramidal  cells.  The  latest  experiments  (Bernheimer) 
place  this  centre  in  that  portion  of  the  inferior  parietal  lobule  known  as 
the  angular  gyrus. 

32 


40«  DISEASES    OF    THE    EYE.  [chap.   xvii. 

sphere  ;  aud  hence,  even  when  conjugate  lateral  deviation  plays  the 
part  of  a  direct  cortical  symptom,  it  rarely  can  be  recognised  as 
such,  owing  to  its  evanescent  character.  In  paralysing  lesions  the 
deviation  of  the  eyes  is  of  course  towards  the  side  of  the  lesion — 
the  eyes  look  at  the  cerebral  lesion,  as  Prevost  has  expressed  it — 
while  in  irritating  lesions  the  spasm  of  the  afltected  muscles  causes 
the  deviation  to  be  from  the  side  of  the  lesion,  that  is,  towards  the 
convulsed  limbs  if  convulsions  be  present.  These  conditions  are 
the  reverse  of  what  happens  in  conjugate  lateral  deviation  due  to 
lesions  in  the  pons  (p.  495),  and  we  are  thus  enabled  to  differentiate 
between  lesions  in  the  two  positions. 
There  are  four  possible  cases  : — 

^      ,      -  ^      .          (  Destructive.     Eyes  turned  away  from  paralysed  side. 
Cerebral  Lesions      -r    •.  .•  ^  a  ^     a      a 

I  Irritative.  ,,  ,,       towards  convulsed  side. 

^       .       ^      .  /  Destructive.  ,,  ,,       towards  paralvtic  side. 

Pontine  Lesions   \  ^    .,   ^.  s  ^     a    ■  ^ 

\  Irritative.  ,,  ,,       away  irom  convulsed  side. 

The  cerebral  cases  show  that  the  centre  for  associated  movements 
is  on  the  opposite  side  of  the  brain — e.g.  in  movements  of  eyes  to 
the  left,  the  left  external  rectus  and  right  internal  rectus  are  inner- 
vated by  the  right  hemisphere  of  the  brain  ;  consequently,  a  destruc- 
tive lesion  here  would  produce  paralysis  of  the  left  side  of  the^  body 
and  of  the  associated  movements  of  the  above  orbital  muscles, 
and  therefore  the  eyes  w^ould  be  drawn  to  the  right  by  their  oppon- 
ents— i.e.  away  from  the  paralysed  side.  A  destructive  lesion  of 
the  right  side  of  the  pons  would  also,  of  course,  produce  paralysis 
of  the  left  side  of  the  body ;  but,  involving  the  right  sixth 
nucleus  (see  also  p.  495),  it  would  cause  paralysis  of  the  associated 
movements  of  the  right  external  rectus  and  left  internal  rectus, 
and,  consequently,  the  eyes  would  be  drawn  to  the  left  by  the 
opponents — i.e.  towards  the  paralysed  side. 

The  reverse  of  the  foregoing  would  occur  in  irritative  lesions. 
Fig.  200  serves  to  illustrate  the  points  referred  to. 

A  destructive  lesion  at  12,  the  right  cortical  centre,  involving 
also  motor  centres  of  the  body,  would  cause  left  hemiplegia  ;  and, 
since  the  external  rectus  of  the  left  eye  and  internal  rectus  of  the 
right  eye  would  be  paralysed,  the  antagonists  would  turn  the  eyes 
to  the  right — i.e.  away  from  the  paralysed  side.  A  destructive 
lesion  of  the  right  side  of  the  pons,  also  producing  left  hemiplegia, 


XVTT.] 


TEE    ORBITAL    MUSCLES. 


409 


if  it  involve  the  sixth  nucleus,  will  produce  paralysis  uf  the  external 
rectus  of  the  right  eye  and  of  the  internal  rectus  of  the  left  eye, 
and  the  antagonists  would  turn  the  eyes  to  the  left — i.e.  towards  the 
paralysed  side.  Obviously  irritative 
lesions  would  produce  exactly  the 
opposite  effects. 

When  the  acute  symptoms  have 
passed  off,  the  conjugate  deviation, 
due  to  irritation,  disappears  even 
though  a  conjugate  paralysis  and 
hemiplegia  may  remain. 

Hemianopsia  interferes  to  a  certain 
extent  with  the  conjugate  movement 
towards  the  affected  side,  in  so  far  as 
this  is  guided  by  visual  impressions 
(p.  370).  According  to  Knies,  the 
difficulty  in  reading  in  right  hemia- 
nopsia is  mainly  due  to  this  cause. 

Conjugate  deviations  have  been 
found  with  disease  of  the  middle 
peduncle  of  the  cerebellum,  of  the 
pons,  corpora  quadrigemina,  optic 
thalamus,  and  cerebral  cortex. 

Some  authors  (Sauvineau)  believe 
that  a  lower  centre  exists  in  the 
grey  matter  of  the  corpora  quadri- 
gemina overlying  the  aqueduct  of 
Sylvius,  which  regulates  the  associated 
movements  of  the  eyes,  it  would  thus 
constitute  a  supra-nuclear  co-ordinat- 
ing centre  intervening  between  the  cortical  centre  and  the  nerve 
nuclei.  Lesion  of  a  centre  of  this  kind  would  readily  explain 
associated  vertical  deviations  as  well  as  lateral  deviations. 

In   conjugate   deviations   the   internal   rectus   involved   is   still 


Fig.  200.— 1.  Left  Ext. 
Rectus  ;  2.  Left  Int.  Rectus  ; 
3.  Right  Int.  Rectus ;  4.  Right 
Ext.  Rectus  ;  5.  Nucleus  left 
third  nerve  ;  6.  Nucleus  right 
third  nerve  ;  7  and  8  Post, 
longitudinal  bands  from  sixth 
nerve  to  opposite  third  nerve  ; 

9.  Nucleus  left  sixth  nerve  ; 

10.  Nucleus  right  sixth  nerve  ; 
11  and  12.  Left  and  right  cor- 
tical centres.  An  impulse 
starting  from  12  would  travel 
down  to  9,  and  produce  an 
associated  movement  of  the 
eyes  to  the  left.i 


1  According  to  Bernheimer's  view,  in  the  above  diagram  9  (6th  nucleus) 
would  be  connected  with  5  (3rd  nucleus  of  same  side)  and  from  5  some 
fibres  would  also  pass  into  the  opposite  3rd  nerve  through  6.  It  simply 
means  that  the  decussation  would  take  place  lower  down. 


r.OO  DISEASES    OF    THE    EYE.  [chap.   xvii. 

capable  of  taking  part  in  the  act  of  convergence  ;  moreover,  diplopia 
does  not  occur  since  there  is  no  strabismus. 

It  seems  important  here,  even  at  the  lisk  of  some  repetition,  to 
direct  special  attention  to 

^=  The  Localising  Value  of  Paralyses  of  Orbital  Muscles  in  Cerebral 
Disease. — Paralysis  of  the  Third  Nerve.  As  regards  this  nerve  we 
are  struck  with  the  fact  that  ptosis,  partial  or  complete,  may  be 
present  as  a  focal  symptom  in  cortical  lesions — cerebral  ptosis,  as  it 
is  called — without  any  other  third-nerve  branch  being  paralysed. 
That  a  separate  cortical  centre  for  this  branch  of  the  third  nerve 
exists,  and  that  it  innervates  the  muscle  of  the  opposite  side,  is  very 
probable.  The  existence  of  such  a  centre  would  not  be  inconsistent 
with  the  view  that,  as  regards  the  motions  of  the  eyeballs,  associated 
centres  alone  are  present ;  for,  although  as  a  rule  the  elevators  of 
the  lids  are  associated  in  their  motions,  yet  by  an  effort  of  the  will 
most  people  can  throw  one  of  them  into  motion  separately,  or  more 
than  the  other.  No  doubt  the  power  to  voluntarily  innervate  one 
levator  and  orbicularis  alone  varies  in  different  individuals,  and  in 
many  persons  the  levator  centres  are  practically  associated  centres, 
and  probably  this  is  the  reason  w^hy  cerebral  ptosis  is  rather  rare. 
The  position  of  this  centre  is  still  an  open  question,  but  it  is  believed 
to  be  situated  in  front  of  the  upper  extremity  of  the  ascending  frontal 
convolution  close  to  the  arm  centre. 

Ptosis,  then,  has  no  value  as  indicating  the  locality  of  a  lesion  in 
the  cortex  ;  but  it  may  be  of  use  in  distinguishing  a  cortical  lesion 
from  one  situated  elsewhere  in  the  brain,  for  monolateral  ptosis,  as 
the  only  focal  symptom,  occurs  with  cortical  lesions  alone. 

It  is  probable  that  ptosis,  as  the  result  of  a  cortical  lesion,  is  a 
distant  symptom  in  not  a  few  of  the  cases  where  it  is  present. 

Ptosis  on  the  side  of  the  lesion  has  occasionally  formed  a  symptom 
in  disease  of  the  pons,  without  paralysis  of  the  other  branches  of  the 
third  nerve — except,  sometimes,  in  so  far  as  conjugate  deviation 
{vide  supra)  is  concerned — and  without  the  third  nerve  being  involved 
in  the  lesion. 

Again,  ptosis,  by  forming  a  factor  of  a  crossed  paralysis,  may 
serve  to  localise  a  lesion  in  the  crus  cerebri.  When  the  third  nerve 
is  paralysed  by  a  lesion  in  this  situation  it  is  the  rule  to  find  it  para- 
lysed as  a  whole  ;  but  paralysis  of  only  some  of  the  third-nerve 
branches  may  be  produced  by  a  lesion  of  the  cerebral  peduncle,  and 


CHAP.  XVII.  1  THE   ORBITAL   MUSCLES.  501 


the  branch  to  the  levator  palpebrse  seems  to  be  the  one  most  fre- 
quently implicated  alone. 

To  complete  the  subject  of  ptosis,  mention  must  be  made  of 
Sy7n/pathctic  Ptosis  which  is  accompanied  by  other  eye-symptoms, 
as  well  as  by  symptoms  of  vasomotor  paralysis  of  one  side  of  the  body, 
such  as  elevation  of  temperature,  and  redness  and  oedema  of  the 
skin.  In  these  cases,  there  is  (1)  apparent  ptosis  on  the  paralysed 
side,  owing  to  the  contraction  of  the  palpebral  aperture,  but  the  lid 
can  be  raised  ;  (2)  contraction  of  the  pupil  on  the  same  side  ;  (3) 
diminished  intra-ocular  tension  ;  (4)  a  shrinking  back  of  the  eyeball 
into  the  orbit,  so  that  it  seems  to  have  become  smaller  ;  (5)  an  ab- 
normal secretion  of  thin  mucus  from  the  corresponding  nostril,  of 
tears  from  the  affected  eye,  and  of  saliva  from  the  corresponding  side 
of  the  mouth.  In  the  later  stage,  the  side  of  the  face  becomes  paler 
and  thinner,  its  temperature  is  lower,  and  it  perspires  less  than  the 
other  side,  or  not  at  all.  This  train  of  symptoms  has  been  found  in 
lesions  of  the  corpus  striatum,  but  is  chiefly  due  to  lesions  of  the 
cervical  sympathetic,  or  of  the  spinal  cord  at  or  above  the  level  of 
the  eighth  cervical  and  first  dorsal  nerve,  or  of  these  nerves  alone. 

A  common  sign  of  disease  of  the  crus  cerebri  is  what  is  known  as 
Crossed  Hemiplegia.  Paralysis  of  the  third  nerve,  on  the  side  of  the 
lesion,  with  hemiplegia,  hemiansesthesia,  often  facial,  and  sometimes 
hypoglossal,  paralysis  on  the  opposite  side  of  the  body  is  a  frequent 
form  of  it.  The  lesion  may  implicate  all  the  branches  of  the  third 
nerve,  or  only  some  of  them.  The  optic  tract  lying  as  it  does  close 
to  the  crus  may  also  be  affected  by  the  lesion  which  would  then  give 
rise  to  hemianopsia  on  the  same  side  as  the  hemiplegia.  But  the 
localising  value  of  crossed  hemiplegia,  as  Hughlings  Jackson  long 
ago  pointed  out,  depends  chiefly  on  the  hemiplegia  and  paralysis  of 
the  cranial  nerve  coming  on  simultaneously.  If  they  occur  at  differ- 
ent times  they  may  be  due  to  two  distinct  lesions,  neither  of  which 
may  be  in  the  crus  ;  for  the  hemiplegia  might  be  due  to  a  lesion  in 
the  hemisphere,  and  the  third-nerve  paralysis  to  a  basal  lesion  of 
earlier  or  later  date.  Yet  a  few  cases  have  been  observed  where, 
with  a  lesion  in  the  cerebral  peduncle,  the  third-nerve  paralysis 
preceded  the  hemiplegia  by  a  considerable  interval. 

That  basal  lesions  are  by  far  the  most  frequent  cause  of  paralysis 
of  the  third  nerve  is  beyond  doubt  :  and  here  it  is  usual,  but  not 
constant,  to  find  it  paralysed  in  all  its  branches.     The  diagnosis  to 


502  DISEASES   OF   THE   EYE.  [chap.  xvii. 

be  made,  when  direct  symptoms  are  being  considered,  is,  for  the 
most  part,  between  a  lesion  in  the  crus  and  a  lesion  at  the  base.  We 
cannot  pretend  to  be  able  to  make  this  diagnosis  with  certainty  in 
all  cases.  Complete  paralysis  of  every  branch  of  the  third  nerve 
without  any  other  paralysis  is  almost  always  basal ;  so  also  are  those 
cases  in  which,  where  there  is  hemiplegia,  it  is  slight,  as  compared 
with  the  degree  of  the  third-nerve  paralysis  ;  and  those  cases,  too, 
to  which  reference  has  already  been  made,  where  there  is  an  interval 
between  the  onset  of  the  paralysis  of  the  extremities  and  of  the 
third  nerve,  are  apt  to  be  basal.  Of  course  there  may  be  such  a 
combination  of  paralyses  of  the  other  cerebral  nerves  with  that  of 
the  third  nerve,  as  to  leave  no  doubt  with  reference  to  the  basal 
position  of  the  lesion. 

The  third  nerve  may  be  paralysed  by  lesions  in  the  inter-pedun- 
cular space,  in  which  case  the  paralysis  may  be  partial  (ptosis  alone, 
or  abolition  of  upward  and  downward  motion  alone),  complete, 
monocular,  or  binocular.  This  is  the  commonest  situation  for  a 
syphilitic  basal  affection,  which  may  extend  in  a  forward  direction 
and  involve  the  chiasma  as  well.  When  both  nerves  are  affected 
there  is  generally  also  paralysis  of  the  other  orbital  nerves,  or  of  the 
facial  nerve  ;    and  hemiplegia  or  hemianopsia  may  also  be  present. 

Thrombosis  of  the  Cavernous  Sinus  invariably  produces  paralysis 
of  the  third  nerve  ;  but  all  the  orbital  nerves,  as  well  as  the  fifth 
and  the  optic  nerve,  may  also  be  involved,  giving  rise  to  complete 
immobility  of  the  eye,  with  loss  of  conjunctival  and  corneal  sensa- 
tion. The  pupil  is  usually  contracted  at  first,  but  later  on  dilates. 
The  venous  obstruction  causes  exophthalmos,  oedema  of  the  lids,  and 
chemosis.  The  ophthalmoscope  sometimes  shows  the  presence  of 
congestion  papilla.  The  general  symptoms  are  rigors,  high  tempera- 
ture, and  vomiting.  Its  principal  causes  are  infective  inflammation 
of  the  orbital  cavity  or  nasal  sinuses  ;  erysipelas  of  the  face  ;  infec- 
tive inflammation  in  the  buccal,  nasal,  and  pharyngeal  cavities, 
and  of  the  body  of  the  sphenoid  ;  and  extension  of  thrombosis 
of  the  sinuses  from  purulent  otitis.  The  thrombosis  in  more  than 
half  the  cases  spreads  to  the  other  side  through  the  circular  sinus. 
When  the  invasion  occurs  from  the  intracranial  direction,  pain  in 
some  or  all  of  the  branches  of  the  fiist  division  of  the  fifth  nerve 
is  usually  an  early  syin])t(^in. 

Third-nerve  symptoms — in  addition  to  those  included  uiuler  the 


CHAP,  xvii.l  THE    ORBITAL   MUSCLES.  503 


headings  conjugate  deviation,  or  paralysis,  and  ptosis — are  some- 
times distant  symptoms.  Tumours  of  the  cerebral  hemispheres, 
more  particularly  if  accompanied  by  violent  general  head  symptoms, 
indicating  probably  high  intracranial  pressure,  are  the  lesions  most 
apt  to  produce  these  distant  third-nerve  symptoms.  As  a  rule,  the 
slighter  the  general  cerebral  symptoms,  the  more  likely  are  the  third- 
nerve  paralyses  to  be  direct  symptoms.  This  rule,  indeed,  applies 
to  other  as  well  as  to  third-nerve  focal  symptoms. 

Paralysis  of  the  Fourth  Nerve,  when  combined  with  paralysis  of 
other  motor  eye-nerves,  is  difficult  to  recognise  ;  and  consequently 
in  such  cases  it  furnishes  but  little  aid  for  localisation.  Solitary 
paralysis  of  this  nerve  as  a  symptom  of  cerebral  focal  lesion  is  ex- 
tremely rare.  Nieden  has  placed  a  case  on  record  in  which  paralysis 
of  one  fourth  nerve  was  the  only  focal  symptom  to  which  a  tumour 
of  the  pineal  gland,  of  the  size  of  a  walnut,  gave  rise.  But  the 
isolated  fourth-nerve  paralysis  is  more  apt  to  be  produced  by  a 
basal  lesion.  Pfungen  has  pointed  out  that,  in  meningitis,  exudation 
in  the  space  between  the  corpora  quadrigemina  and  the  splenium 
of  the  corpus  callosum  may  implicate  the  fourth  nerves  in  the  valve 
of  Yieussens,  and  believes  it  is  prone  to  do  so  in  tubercular  mening- 
itis. In  combination  with  paralysis  of  the  third  nerve  it  speaks  for 
a  lesion  in  the  cerebral  peduncle,  extending  back  to  the  valve  of 
Vieussens. 

Pseudo-paralysis  of  the  fourth  nerve,  usually  only  transitory, 
sometimes  occurs  after  radical  operations  on  the  frontal  sinus,  from 
displacement  of  the  pulley  of  the  superior  oblique  muscle. 

When  Paralysis  of  the  Sixth  Nerve  occurs  as  the  only  focal  sign 
it  is  probably  due  to  disease  at  the  base,  or  it  is  a  distant  symptom. 
There  is  no  cranial  nerve  so  liable  to  provide  a  distant  symptom  as 
the  sixth.  Gowers  refers  this  liability  to  the  lengthened  course  this 
nerve  takes  over  the  most  prominent  part  of  the  pons,  which  renders 
it  readily  affected  by  distant  pressure.  One  or  both  nerves  may  in 
this  way  be  paralysed.  Wernicke  states  that  sixth-nerve  paralysis 
is  most  apt  to  be  present  as  a  distant  symptom,  when  the  lesion, 
especially  a  tumour,  is  situated  in  the  cerebellum  ;  differing  in  this 
way  from  the  third  nerve,  which  is  more  likely  to  give  distant 
symptoms  with  a  lesion  in  the  cerebral  hemisphere. 

Paralysis  of  the  sixth  nerve,  simultaneous  in  its  onset  with 
hemiplegia  of  the  opposite  side  of  the  body,  indicates  a  lesion  in  the 


504  DISEASES    OF    THE   EYE.  [chap.   xvii. 

pons,  usually  a  ha3morrliage,  on  the  side  corresponding  with  the  para- 
lysed nerve.  We  know  that  the  fiftli  and  facial,  and  sometimes  the 
auditory,  spinal  accessory,  and  hypoglossal  nerve,  may  all,  in  varying 
combinations,  form  one  of  the  elements  in  a  crossed  paralysis  from  a 
lesion  in  this  position  ;  but  if  special  localising  value  is  to  be  given 
here  to  the  participation  of  any  one  cranial  nerve,  that  nerve  is  the 
sixth.  The  paralysis  of  this  nerve,  simultaneously  with  palsy  of 
the  opposite  side  of  the  body,  while  other  conditions  point  to  an 
intracranial  lesion,  speaks,  then,  almost  certainly  for  pontine  disease. 

Basal  paralysis  of  the  sixth  nerve  is  frequently  double,  especially 
in  syphilis.  Fracture  of  the  apex  of  the  petrous  portion  of  the 
temporal  bone  may  also  cause  it. 

Paralysis  of  the  facial  with  the  sixth  is  not  an  uncommon  com- 
bination caused  by  a  lesion  in  the  pons,  which  at  the  same  time 
produces  hemiplegia  of  the  opposite  side  of  the  body.  This  com- 
bination is  a  natural  one,  in  view  of  the  close  relations  of  the  nuclei 
of  the  sixth  and  seventh  nerves.  The  manner  in  which  the  root  of 
the  facial  nerve  winds  round  the  sixth-nerve  nucleus  must  also  have 
an  important  bearing  on  the  occurrence  of  associated  paralyses  of 
these  nerves. 

Paralysis  of  one  or  both  sixth  nerves  sometimes  occurs  in  con- 
nection with  a  purulent  otitis  media  without  any  symptoms  of 
intracranial  complications,  and  is  not  usually  a  sign  of  serious 
importance,  although  in  some  cases  it  may  be  the  first  symptom  of 
intracranial  mischief.  It  is  probably  due  to  a  localised  area  of 
infection,  causing  slight  meningitis  or  necrosis  at  the  apex  of  the 
petrous  bone  or  the  infective  material  may  be  carried  up  through  the 
carotid  canal,  but  on  the  other  hand  it  may  be  reflex  in  character, 
and  may  be  brought  about  by  the  connection  of  the  sixth  nerve 
with  Deiter's  nucleus  into  which  the  vestibular  nerves  pass. 

Hemiplegia  due  to  a  lesion  of  the  cortical  motor  region,  wliich 
might  happen  to  be  combined  with  paralysis  of  the  sixth  nerve  as  a 
distant  symptom,  offers  no  difficulty  in  its  diagnosis  from  hemiplegia 
with  sixth-nerve  paralysis  in  pontine  disease  ;  for,  while  in  the 
latter  the  paralysis  is  crossed,  in  the  former  it  is  homonymous. 

Parah/sis  of  the  Seventh  Nerve.  When  lagophthalmos  occurs  as 
a  symptom  in  focal  cerebral  disease,  it  is  useful  in  localising  the 
disease  by  assisting  in  differentiating  a  lesion  in  the  internal  capsule, 
or  in  the  facial  motor  centre  of  the  cortex,  from  one  implicating  the 


CHAP.    XVII. 


THE    ORBITAL    MUSCLES. 


505 


portio  dura  in  the  pons,  as  it  is  absent,  or  very  slight,  in  the  former 
cases,  but  very  often  markedly  present  in  the  latter.  With  a  lesion 
in  the  lower  part  of  the  pons  we  are  apt  to  have  la,Lfoplithalmos  with 
crossed  hemiplegia  ;  but  if  the  lesion  be  in  the  upper  part  of  the 
pons — the  fibres  from  the  opposite  side  having  here  joined  the 
motor  tract — the  hemiplegia  and  lagophthalmos  will  be  homony- 
mous. 

Paralysis  of  the  Fifth  Nerve,  with  hemiplegia  of  the  opposite 
side,  points  to  disease  in  the  pons.  Neuroparalytic  ophthalmia  is 
said  to  be  the  rule  in  basal  lesions  of  the  fifth  nerve,  and  to  occur 
very  rarely  in  nuclear  or  fascicular  lesions. 

The  Orbicular  Sign  may  be  noticed  in  some  attacks  of  apoplexy 
with  hemiplegia  after  consciousness  has  returned.  It  consists  in 
this,  that  the  hemiplegic  person,  who  during  health  has  been  able 
to  close  each  eye  separately,  and  who  even  now  can  close  both  eyes 
together,  or  the  eye  on  the  sound  side  alone,  is  unable  to  close  the 
eye  on  the  paralysed  side  by  itself.  This  sign  usually  passes  away 
after  a  short  time.  Sometimes  when  both  eyes  are  closed  it  requires 
a  greater  effort  to  bring  the  eyelids  together  on  the  paralysed  side. 

Extensive  basal  lesions,  especially  those  due  to  syphilitic  disease, 
may   produce   symptoms   due  to   involvement   of  widely  separate 
structures,  without  interfering  with  those  which  intervene  ;    hence 
they  tend  to  implicate   several   nerves 
without  reference  to  system  or  function. 

*  Congenital  defects  of  motion  of 
the  eyes  are  not  very  uncommon, 
and  are  sometimes  hereditary.  Ptosis 
(chap,  xviii.)  with,  or  without  defect  of 
upward  movement  of  the  eyeballs,  is 
the  commonest  form,  and  is  often  asso- 
ciated with  epicanthus  (Fig.  201),  but 
all  degrees  of  impairment  of  mobility, 
and  even  total  loss  of  motion,  may  be 
met  with,  as  well  as  unnatural  asso- 
ciated movements  of  the  eyes.  In 
paralysis  of  outward  movement,  re- 
traction of  the  eyeball  occurs  in  some 

cases  on  looking  inwards.     The  powdr  of  convergence  is  frequently 
retained,    although    lateral    movement    may    be    impaired   or   ab- 


Fig.  201. — Congenital  ptosis 
with  epicanthus. 


)0r>  DISEASES   OF    THE    EYE.  \chav.   xvii. 


sent.  The  pupils  and  accommodation  escape  as  a  rule.  There 
is  no  diplopia  or  secondary  deviation  as  in  acquii-ed  paralysis. 
(According  to  Duane  secondary  deviation  does  occur  and  diplopia 
can  be  induced.)  Vision  is  usually  impaired,  and  the  patients  are 
often  mentally  dull.  The  defective  mobility  is  due  to  absence  or 
defect  (aplasia)  of  the  muscles,  nerves,  or  nuclei.  For  congenital 
ptosis  with  associated  lid-movement  see  chap.  xvii. 

Strabismus  Fixus  is  a  rare  condition  in  which  both  eyes  are 
turned  inwards  to  an  extreme  degree  and  practically  immovable. 
It  is  probably  the  result  of  a  form  of  congenital  ophthalmoplegia. 
It  is  almost  impossible  to  remedy  it  by  operation  owing  to  secondary 
contracture  of  the  muscles,  and  probably  also  of  the  capsule  of 
tenon. 


Convergent  Concomitant  Strabismus  (Non-Paralytic 
Strabismus). 

This  is  the  condition  which  is  popularly  known  as  inward  '  cast ' 
or  '  squint.'  It  makes  its  appearance  in  children,  when  they  begin 
to  take  an  interest  in  small  objects,  such  as  toys  and  pictures  ;  or 
a  little  later,  when  the  first  lessons  are  learned — in  short,  when  they 
begin  to  make  frequent  and  prolonged  demands  on  their  internal 
recti  and  accommodation,  most  commonly  from  the  age  of  three  to 
six  years. 

It  is  non-paralytic,  and  the  term  '  concomitant '  {concomitatus , 
accompanied)  is  given  to  it  in  contradistinction  to  '  paralytic  ' 
strabismus,  because  in  it  the  squinting  eye  accompanies  the  straight 
one  in  all  its  movements  to  an  equal  extent.  In  the  primary  position 
of  the  eyeballs,  in  a  case  of  concomitant  squint,  the  parallelism  of 
the  visual  axes  is  defective,  and,  as  the  eyes  are  moved  from  side  to 
side,  the  defective  parallelism  continues  in  the  same  degree,  neither 
increasing  nor  decreasing  Moreover,  the  secondary  deviation  (p. 
477),  in  the  sound  eye,  in  these  cases  of  concomitant  strabismus,  is 
equal  in  degree  to  the  primary  deviation  of  the  squinting  eye ; 
because  the  internal  rectus  of  the  good  eye  being  associated  in  its 
action  with  the  external  rectus  of  the  squinting  eye,  when  the  latter 
)nuscle  is  forced  to  roll  its  eye  outwards  in  order  to  bring  it  to  fixa- 
tion, tlic  iiiteiiial  rectus  of  tlie  g(»o(l  eye,  receiving  a  similar  nervous 
impulse,  rolls  that  eye  inwaids  to  the  same  extent  as  the  squinting 


CHAP.  xviT.]  THE    ORBITAL   MUSCLES.  507 

eye  has  been  rolled  outwards.  The  good  eye  will  therefore  present, 
under  the  covering  hand,  an  internal  strabismus  of  the  same  amount 
as  that  which  has  previously  been  present  in  the  squinting  eye. 
This  is  an  important  point,  for  it  is  an  aid  in  the  differential  diagnosis 
of  this  form  of  strabismus  from  the  paralytic  form,  in  which  the 
secondary  deviation  is  greater  than  the  primary  one  (see  General 
Principle  No.  2,  p.  477).  Diplopia  and  giddiness  are  absent  in 
concomitant  strabismus. 

In  concomitant  strabismus,  both  eyes  never  squint  simultane- 
ously, as  one  hears  it  sometimes  stated  by  parents  ;  although  the 
excessive  convergence,  as  will  be  explained  later  on,  is  present  in 
both. 

The  method  of  distinguishing  the  squinting  eye  from  the  fixing 
eye  is  given  at  p.  472. 

Bonders  pointed  out  that,  in  a  large  proportion  of  cases  of  con- 
vergent strabismus,  the  refraction  is  hypermetropic  ;  and  he  drew 
the  conclusion  that  hypermetropia  is  to  be  regarded  as  the  cause  of 
the  strabismus  in  the  following  way  : — It  has  been  shown  (p.  8) 
that  with  each  degree  of  normal  convergence  of  the  optic  axes,  for 
the  purpose  of  single  vision,  a  certain  effort  of  accommodation,  in 
order  to  see  the  object  distinctly,  is  associated.  The  greater  the 
angle  of  normal  convergence,  the  greater  is  the  possible  effort  of 
accommodation. 

Of  this  physiological  fact,  Bonders  said,  the  hypermetrope  often 
unconsciously  takes  advantage,  and  in  order  to  brace  up  his  ac- 
commodation in  an  excessive  degree  for  the  sake  of  distinct  vision 
with  one  eye,  he  increases  the  angle  of  convergence  of  the  optic 
axes. 

The  over-convergence  is  not,  however,  as  usually  described, 
limited  to  the  squinting  eye  ;  both  take  part  in  it,  and  the  effect 
is  to  render  the  strabismus  manifest  in  the  eye  which  does  not  fix. 
To  explain  this  it  may  be  desirable  to  consider  what  occurs,  when 
convergence  and  accommodation  are  normal.  In  Fig.  202  the  eyes 
are  converging  on,  or  fixing,  the  point  0,  and  the  object  is  seen  singly, 
and  at  the  same  time  distinctly,  because  the  amount  of  accommoda- 
tion required  is  normally  associated  with  this  degree  of  convergence. 
Although  the  right  eye  (R)  is  in  the  primary  position,  it  is  taking 
part  in  the  act  of  convergence  as  much  as  the  left  eye  (Fj).  If  0 
were  at  0',  at  the  same  distance  from  the  eyes  but  in  the  middle 


508 


DISEASES   OF    THE   EYE. 


[chap.    XVII. 


202. — Binocular 
with  convergence  and  accommoda- 
tion for  O. 


line,  L  and  R  would  converge  through  equal  angles,  a  and  h.     Now, 

if  the  eyes  make  a  lateral  movement  to  the  right  (arrow  3),  the  de- 
viation of  L  would  be  made  up  of 
the  angles  a  and  c,  a  being  due  to 
convergence,  and  c  to  the  lateral 
movement  in  the  same  direction, 
both  brought  about  by  the  left 
internal  rectus  ;  whereas  the  con- 
vergence in  R  (arrow  2),  due  to 
the  internal  rectus,  is  neutralised 
by  the  lateral  movement  (arrow 
3)  which  is  in  the  opposite  direc- 
tion in  this  eye.  If  this  eye  had 
not  been  converging,  it  would 
have  remained  parallel  to  L  0 
in  the  lateral  movement,  and 
would    have    moved    outw^ards. 

L  is  considerably  rotated  inwards,  but  it  is  not  squinting,  because 

it  is  fixing  0. 

Fig.     203     represents      concomitant     convergent     strabismus. 

The     patient    wishes    to    see 

the    object    at    0    distinctly, 

but    owing    to    his   hyperme- 

tropia,     the     accommodation 

normally  associated  with  this 

degree  of  convergence  is  not 

sufficient.     By  converging  for 

a  nearer  point  (B)  an  addi- 
tional effort  of  accommoda- 
tion can   be   made,   but  then 

the  patient  could   not  fix   0, 

and  it  would  appear  double. 

In  order  to  avoid  this  di- 
lemma a  lateral  movement  of 

the  eyes  is  made   from  B  to 

B'.  and  thus  the  right  eye  (R) 

is  brought  into   lino   witli   O, 

and  sees  it  distinctly  by  mean; 

gained  l)y  convergence  for  B, 


Fig.  203. — Concomitant  convergent 
strabismus  ;  binocular  convergence  for 
B'  with  monocular  fixation,  and  ac- 
commodation for  O. 

i  of  tlio  additional  accommodation 
Tlie  left  eye  now  Jio  longer  fixes  0, 


riTAP.  xvTT.l  THE    OnniTAL    MUSCLES.  500 


and  therefore  squints.  The  deviation  of  the  squinting  eye  is  made 
up  of  the  angles  a  (excess  of  convergence  for  B)  and  c  (lateral  move- 
ment to  B").  In  the  right  eye,  the  excess  of  convergence  is  neutra- 
lised by  the  lateral  motion  in  the  opposite  direction.  In  fact,  it  is 
only  the  desire  for  fixation  which  keeps  both  eyes  from  squinting. 
In  some  cases  there  is  no  lateral  movement,  as  the  patient  turns  his 
head,  in  the  above  case  to  the  right,  to  bring  the  right  eye  into  line 
with  0. 

Inasmuch  as  all  hypermetropes  do  not  squint,  Donders  con- 
sidered that  there  were  contributing  circumstances,  which  caused 
each  hypermetrope  to  unconsciously  decide  between  distinct  mono- 
cular vision  with  strabismus,  and  indistinct  binocular  vision.  The 
latter,  he  said,  is  likely  to  be  preferred  if  the  condition  of  the  refrac- 
tion and  the  acuteness  of  vision  is  the  same  in  each  eye  ;  while,  if 
one  eye  be  amblyopic,  or  if  the  retinal  images  differ  much,  by  reason 
of  one  eye  being  more  ametropic  than  its  fellow — from  nebulous 
cornea,  or  from  other  causes — the  desire  for  binocular  vision  would 
be  less  strong,  and  the  imperfect  eye  would  deviate  inwards  for  the 
sake  of  the  resulting  increase  of  accommodation  in  the  perfect  eye. 

It  is  admitted  that  hypermetropia  is  one  of  the  causes  of  internal 
strabismus,  but  it  is  not  the  only  cause,  and  probably  not  even  the 
principal  cause,  for  the  following  reasons  : — (1)  If  Donders'  theory 
be  complete,  convergent  strabismus  must  always  appear,  whenever 
there  is  binocular  hypermetropia,  along  with  the  conditions  which 
reduce  the  value  of  binocular  vision.  But  strabismus  is  often  absent, 
while  the  degree  of  ametropia  is  markedly  different  in  the  two  eyes, 
or  while  the  acuteness  of  vision  is  very  defective  in  one  eye.  Again, 
the  number  of  cases  of  strabismus  is  very  small  in  proportion  to 
the  number  of  hypermetropes,  since  nearly  all  children  are  hyper- 
metropic. (2)  In  periodic  strabismus,  the  influence  of  hyperme- 
tropia and  of  the  accommodative  effort  is  very  evident ;  and  yet 
these  cases  only  go  to  show  that,  while  hypermetropia  is  very  fre- 
quently one  of  the  causes  of  strabismus,  it  is  not  the  only  or  most 
important  one  ;  for  here,  clearly,  some  factor  necessary  for  the 
production  of  a  permanent  squint  is  wanting.  (3)  Donders'  theory 
fails  to  explain  the  occurrence  of  convergent  strabismus  in  emme- 
tropic and  in  myopic  individuals,  where,  of  course,  no  excessive 
effort  of  accommodation  is  required. 

The  fact  that  very  few  squinters  are  found  amongst  high  hyper- 


510  DISEASES    OF    THE    EYE.  [chap.   xvii. 

metropes  is  not  an  argument  against  Donders'  theory,  as  high 
degrees  of  this  error  are  met  with  much  less  frequently  tlian  low 
or  moderate  degrees,  moreover  the  demand  on  the  accommodation 
in  such  cases  may  be  so  great  that  over-convergence  does  not  enable 
the  patient  to  obtain  sufficient  accommodation  for  distinct  vision. 

Congenital  want  of  equilibrium  between  the  muscles  has  been 
advanced  as  an  explanation  of  convergent  squint,  but  no  proofs 
of  this  preponderance  of  certain  muscles  can  be  given. 

Spontaneous  cure  of  strabismus  sometimes  takes  place,  most 
commonly  between  the  tenth  and  sixteenth  year  of  age.  That  it 
may  happen  with  hypermetropia,  and  with  defective  vision  in  one 
eye,  is  strongly  against  Donders'  theory,  assuming,  of  course,  that 
the  hypermetropia  has  not  diminished  much,  as  it  naturally  tends 
to  do  at  this  time  of  life. 

The  most  probable  cause  is  defective  development  of  the  sense 
of  fusion  (p.  473),  aided  or  caused  by  conditions  which  render  fusion 
difficult,  such  as  hypermetropia,  or  amblyopia,  either  congenital, 
or  acquired  in  early  life.  Illness  may  weaken  accommodation,  and 
the  temporarily  altered  relation  between  the  latter  and  convergence 
may  cause  a  squint  to  appear  even  in  emmetropia,  if  the  sense  of 
fusion  be  imperfect.  In  alternating  strabismus,  where  the  patient 
squints  with  either  eye,  the  vision  is  generally  good  and  equal  in 
both  eyes  ;  yet,  according  to  Worth,  the  faculty  of  fusion  is  always 
wanting  in  these  cases. 

Priestley  Smith  upholds  the  theory  of  the  defective  development 
of  the  sense  of  fusion,  which  is  acquired,  as  stated  before,  in  infancy. 
During  the  first  few  years  of  life,  this  newly  acquired  faculty  is  less 
stable  than  at  a  later  period,  and  is  more  easily  disturbed.  Hence 
the  greater  liability  to  strabismus  in  infancy.  Among  three  hundred 
and  forty-seven  cases,  where  the  onset  age  was  ascertained,  two 
hundred  and  fifty-four,  =:  73  per  cent.,  began  before  the  children 
were  five  years  old.  Three  years  was  the  most  common  age.  The 
hypermetropic  child  is  specially  liable  to  convergent  strabismus, 
because  he  has  to  overcome  a  special  difficulty  :  he  must  learn  to 
converge  normally,  while  he  accommodates  abnormally.  Failing 
in  this,  he  squints  in  order  to  see  clearly.  Many  squints  arise  in 
this  way,  but  the  influence  of  hypermetropia  must  not  be  exagger- 
ated. 

Infantile    disorders — convulsions,    whooping-cough,    measles,    a 


cuw.   xvn.]  THE    ORBTTAL    MUSCLES. 


fright,  a  fall,  etc. — are  often  the  starting-point  of  strabismus, 
because  the  controlling  influence  of  the  higher  brain  centres  is 
weakened  at  such  times.  Priestley  Smith  believes  that  a  con- 
tinuous squint  involves  weakening  or  loss  of  visual  function,  and 
that  the  younger  the  child  the  more  readily  does  this  occur.  The 
sense  of  fusion,  being  no  longer  exercised,  is  gradually  lost,  and 
may  prove  irrecoverable  a  few  years  later,  even  though  the  eyes 
be  made  straight.  Furthermore,  an  eye  which  never  fixes  the 
object  at  which  the  patient  looks,  loses  the  power  of  true  fixation. 
Such  loss  is  found  most  often  amongst  cases  of  early  onset  and 
long  duration  ;  it  is  rarely,  if  ever,  found  until  the  squint  has  become 
continuous  for  at  least  six  months.  Again,  it  is  probable  that  the 
early  onset  of  strabismus,  with  complete  disuse  of  the  squinting  eye, 
may  arrest  the  development  of  form-perception  in  the  latter,  and 
thus  render  it  permanently  amblyopic. 

Single  Vision  in  Concomitant  Strabismus. — For  the  most  part  these 
patients  do  not  complain  of  double  vision,  as  in  cases  of  paralytic  strabismus. 
Why  is  this  ?  The  image  of  the  object  looked  at,  it  will  correctly 
be  said,  must  be  formed  in  the  squinting  eye  in  each  of  these  kinds  of 
strabismus,  on  a  part  of  the  retina  not  identical  with  that  in  the  fixing 
eye,  but  lying  to  the  mesial  side  of  it  ;  and  hence  the  image  of  the  object 
should  be  projected  by  the  squinting  eye  to  its  own  side  of  the  true  position 
of  the  object  (homonymous  diplopia),  and  the  latter  should  therefore  be 
seen  doubled.  It  is  seen  doubled  in  the  paralytic  form  ;  why  not  also  in 
the  concomitant  form  ?  The  explanation  commonly  given  is  that  con- 
vergent concomitant  strabismus  being  a  quasi-physiological  condition,  the 
patient's  mind  involuntarily  suppresses  the  annoying  image  belonging  to 
the  squinting  eye,  in  a  manner  analogous  to  that  by  which,  when  we  are 
deeply  interested  in  conversation,  all  extraneous  sounds  are  unperceived, 
although  they,  too,  must  reach  the  nerve  of  hearing.  This  suppression 
of  the  image  belonging  to  the  squinting  eye  was  believed  to  be  the  more 
easy  owing  to  the  indistinctness  of  the  image  itself,  formed  as  it  is  on  a 
peripheral  part  of  the  retina,  while  in  the  good  eye  it  falls  on  the  macula 
lutea.  We  often  find,  moreover,  that  the  squinting  eye  is  ab  inito  more 
defective  (macula  cornea,  higher  degree  of  hypermetropia,  astigmatism, 
etc.)  than  its  fellow,  and  it  was  held  that  this,  too,  rendered  suppression 
of  its  image  more  easy.  Such  a  suppression  of  the  image  is  possible,  and 
it  no  doubt  does  occur  in  many  cases  of  strabismus  ;  but  it  is  certain  that 
it  does  not  occur  in  all  of  them,  perhaps  not  even  in  the  majority  of  them. 
The  suppression  affects  only  the  macular  region,  for  the  remainder  of  the 
field  of  the  squinting  eye  is  made  use  of  by  the  patient. 

In  those  cases  in  which  the  image  of  the  squinting  eye  is  not  suppressed, 
one  of  two  events  takes  place  : — Either  the  region  of  the  retina,  on  which, 
in  the  squinting  eye,  the  image  of  the  visual  object  is  formed,  becomes 


12  DISEASES    OF    THE    EYE.  [ciiap.   xvtt. 


functionally  developed  into  a  spot  to  a  great  extent  physiologically 
'  identical  '  with  the  macula  lutea  of  the  straight  eye,  and  then  something 
approaching  normal  binocular  fusion  of  the  images  comes  about,  and 
hence  single  vision  ;  or  else,  diplopia  is  actually  present,  although,  as  a 
rule,  it  passes  unnoticed  by  the  patient,  owing  to  its  having  become 
habitual  to  him.  In  some  cases  the  first  of  these  conditions  is  the  actual 
state,  in  others  it  is  the  second  which  exists.  In  support  of  the  first  is 
the  occurrence,  not  rarely  observed,  of  crossed  diplopia  after  operation 
for  concomitant  convergent  strabismus,  even  when  there  is  no  divergence 
produced  ;  and  in  support  of  the  second,  the  diplopia  which  intelligent 
patients  often  admit,  when  they  are  carefully  examined  with  the  aid 
of  a  red  glass  before  the  good  eye.  If  the  strabismus  be  the  result  of  a 
want  of  development  of  the  faculty  of  binocular  vision,  then  the  absence 
of  diplopia  need  not  be  a  matter  for  surpris3. 

Amblyopia  of  the  Squinting  Eye. — In  a  large  proportion  of  the  cases 
of  internal  concomitant  strabismus  the  squinting  eye — even  where  there 
is  no  marked  astigmatism,  and  where  the  media  are  clear — is  amblyopic. 
It  has  been  a  very  generally  accepted  opinion  that  this  amblyopia  is  due 
to  want  of  use  on  the  part  of  the  squinting  eye,  in  consequence  of  the 
suppression  of  the  image  on  its  retina,  and  hence  it  is  termed  amblyopia 
ex  anopsia.  According  to  Schweigger,  if  this  viiew  were  the  correct  one, 
we  ought  always  to  find  only  slight  amblyopia  of  the  squinting  eye  in 
children  soon  after  strabismus  comes  on  ;  while  it  should  be  of  high  degree  in 
adults  who  have  not  been  operated  on,  and  in  whom  mono  lateral  strabismus 
had  been  present  since  childhood.  And  yet  marked  amblyopia  may  often 
be  found  in  children  in  the  squinting  eye,  while  in  adults  the  squinting 
eye  often  has  very  good  vision — in  short,  the  amblyopia  of  the  squinting 
eye  is  not  progressiv^e,  as  it  would  be  were  it  ex  anopsia.  Again,  "many 
squinting  eyes,  when  the  straight  eye  is  covered,  instead  of  fixing  the 
visual  object  with  the  macula  lutea,  remain  unchanged  in  position,  or 
even  turn  inwards  more  than  before  (amblyopia  with  excentric  fixation) ; 
and  in  less  well-marked  cases  of  the  same  sort,  although  there  is  no  excen- 
tric fixation,  yet  the  preference  for  fixation  with  the  macula  lutea  is  lost, 
and  uncertainty  of  fixation  results,  no  one  part  of  the  retina  being  more 
useful  for  that  purpose  than  another.  It  is  held  by  many  that  this  form 
is  characteristic  of  amblyopia  ex  anopsia,  and  is  the  result  of  the  strabismus  ; 
but  it  is  identical  with  a  form  of  congenital  amblyopia,  sometimes  present 
without  strabismus  in  one  eye  only.  Worth,  however,  points  out  that 
in  these  cases  there  is  greater  error  of  refraction  in  the  amblyopic  eye,  and 
that  even  in  spite  of  the  amblyopia  the  fusion  sense  is  well  developed. 
A  strong  argument  in  favour  of  amblyopia  ex  anopsia  is  the  improvement 
which  often  seems  to  take  place  in  the  vision  of  the  squinting  eye  by 
systematic  separate  use,  or  after  the  strabotomy.  Schweigger  thinks  that, 
where  the  improvement  takes  place,  the  defective  vision  has  been  due 
rather  to  retinal  asthenopia  than  to  amblyopia  ;  and  if,  at  the  outset, 
patients  be  pressed  to  discern  the  test-types,  they  often  succeed  in  producing 
a  better  acuteness  of  vision  than  they  at  first  seemed  to  possess.  In  many 
cases,  separate  use  fails  altogether  in  improving  the  vision  of  the  squinting 
eye,  even  when  it  is  not  very  defective — a  fact  which  is  unfavourable  to 


CHAP.  XVII.]  THE    ORBITAL   MUSCLES.  :a\\ 

the  amblyopia  ex  anopsia  theory.  The  circumstance  that  in  alternating 
strabismus  the  sight  of  each  eye  is  good,  cannot  be  regarded  as  proof  in 
favour  of  amblyopia  ex  anoj)sia.  Some  believe  that  the  amblyopia  in 
the  squinting  eye  is  congenital  ;  and,  far  from  being  the  result  of  the 
strabismus,  is  a  factor  in  its  production,  just  as  opacities  of  the  cornea, 
or  high  degrees  of  ametropia,  have  always  been  admitted  to  be.  The 
views  of  different  observers  vary  greatly  on  this  point,  and  depend  very 
much  on  the  age  of  the  patient  wlien  first  treated,  on  tlie  inethods  employed 
for  testing  and  developing  the  ^'ision,  and  on  the  perseverance  of  the 
surgeon,  and  of  the  patient's  parents.  Except  in  cases  of  very  defective 
vision  where  there  may  be  a  central  scotoma  (not  specially  for  any  par- 
ticular colours)  the  field  of  vision  is  normal  in  the  amblyopia  eye. 

Worth's  views  are  similar  to  Priestley  Smith's.  He  believes  that 
tlie  power  of  central  fixation  is  lost  very  rapidly  in  infancy,  and  that 
the  earlier  the  onset  of  the  strabismus  the  greater  will  be  the  amblyopia. 
After  six  years  of  age,  amblyopia  ex  anopsia  seldom  takes  place  to  any 
great  extent.  This  weakens  Schweigger's  argument  based  on  the  non- 
progressiveness  of  the  amblyopia. 

There  are  Three  Clinical  Varieties  of  Convergent  Concomitant 
Strabismus. — (1)  Periodic.  (2)  Permanent  alternating.  (3)  Per- 
manent monolateral.  Periodic  strabismus  occurs  only  now  and 
again,  perhaps  when  a  greater  effort  of  accommodation  is  required. 
It  is  sometimes  the  first  stage  of  permanent  monolateral,  or  of 
alternating  strabismus  ;  but  these  two  latter  forms  do  not  always 
have  their  beginning  in  the  periodic  form,  which  often  continues 
as  periodic  to  the  end  of  the  chapter.  In  alternating  strabismus 
the  patient  squints  with  either  eye  indifferently.  In  permanent 
monolateral  strabismus  the  squint  is  confined  to  one  eye. 

Measurement  of  Convergent  Strabismus. — The  amount  or  degree 
of  the  deviation  of  the  squinting  eye  is  measured  by  one  of  the 
following  methods.  In  all  of  them  it  is  important  that  the  patient 
be  directed,  during  the  test,  to  regard  an  object  placed  in  the  median 
line  and  on  a  level  wdth  his  eyes  (the  Primary  Position,  p.  466). 
The  angle  of  the  squint  usually  increases  with  accommodation  when 
the  object  of  fixation  is  near. 

1.  Hirschberg's  Method  consists  in  making  the  patient  fix  a 
candle  flame,  or  the  ophthalmoscope  mirror,  held  straight  in  front 
of,  and  about  a  foot  from,  the  eyes,  when  the  observer  estimates 
the  degree  of  deviation  by  the  position  of  the  corneal  reflex.  Where 
there  is  no  squint,  this  reflex  is  situated  at,  or  (with  large  angle  y) 
slightly  to  the  inner  side  of,  the  centre  of  the  pupil  in  each  eye. 
In  a  convergent  squinting  eye  it  is  displaced  outwards,  and  Hirsch- 
33 


r)i4 


DISEASES    OF    THE    EYE. 


[chap.   xvtt. 


berg  recognises  five  groups  of  strabismus.  Group  1  (Fig.  '204:  re- 
presenting the  riglit  eye),  in  which  the  leHex  is  nearer  to  the  centre 
than  to  the  margin  of  the  pujjil.  This  represents  a  strabismus  of 
less  than  10''.  Group  2,  in  wliich  the  lefiex  is  at  or  about  the  margin 
of  tlie  pupil,  representing  a  strabismus  of  12^  to  15°.  Group  3,  in 
wliicli  the  reflex  is  outside  tlie  pupilhny  margin,  about  lialf-way 
between   tlie   centre   of  the   pupil   and   tlie   corneal    margin.     This 


iSSf 

y^      ^^      murytn  of     ' 
f             ^^'  Tn^c(itum.(5m'ni)jjupit 

\  1  iTk)'  ) 

,/• 

/    /  y-J_^         cornect . 

i 

^  ^'i  J 

Fig.  204. 


represents  a  strabismus  of  about  25°.  Group  4,  in  which  the  reflex 
is  on  or  near  the  corneal  margin,  represents  a  strabismus  of  45°  to 
50°.  Group  5,  in  which  the  reflex  is  on  the  sclerotic,  between  the 
margin  of  the  cornea  and  the  equator  bulbi.  This  represents  a 
strabismus  of  60°  to  80°.  This  is  a  modification  of  the  linear  method, 
and  is  a  convenient  one  in  routine  practice. 

2.  Priestley  Smith  measures  strabismus  by  means  of  a  double 
tape  (Fig.  205),  used  in  conjunction  wdth  the  ophthalmoscope,  as 
shown  in  the  accompanying  figures.  The  patient  places  the  ring 
P  on  one  of  his  fingers,  and  holds  it  to  his  cheek.  The  observer 
places  the  ring  0  on  the  forefinger  of  the  hand  w^hich  holds  the  oph- 
thalmoscope ;  this  keeps  his  eye  at  a  distance  of  one  metre  from  the 
patient's  face.  He  uses  his  disengaged  hand  as  a  fixation  object 
for  the  patient,  holding  it  edgewise  towards  the  patient,  and  letting 
the  graduated  tape  slide  between  his  fingers.  A  small  weight  at 
the  end  of  the  tape  keeps  it  stretched,  as  the  hand  moves  in  either 
direction. 

Fig.  206  illustrates  the  measurement  of  a  convergent  strabismus 
of  the  right  eye.  The  patient,  seated  below  the  lamp  and  holding 
the  tape  as  above  described,  is  told  to  look  at  the  mirror.  The 
observer,  holding  the  ring  0  and  the  mirror  in  the  right  hand,  throws 
the  light  on  the  patient's  left  eye  (L) — i.e.  the  fixing  eye.     He  sees 


CHAP.   XVTI.] 


THE    ORBITAL    ^rT'SCLf:S. 


the  corneal  reliex  in  the  centre  of  the  pupil,  and  knows  thereby  that 
this  eye  is  fixing  properly.  He  then  throws  the  light  on  the  right 
eye  (R),  and  sees  the  reflex  situated  eccentrically  outwards,  and 
knows  that  this  eye  deviates  inwards.  Taking  the  graduated  tape 
between  the  fingers  of  his  left  hand,  and  telling  the  patient  to  watch 
this  hand,  he  moves  it  outwards  along  the  tape,  and  meanwhile 
watches  the  corneal  reflex  in  the  deviating  eye.  When  the  reflex 
reaches  the  middle  of  the  pupil  the  observer  reads  the  position  of 
the  hand  upon  the  tape.  The  axis  of  the  deviating  eye  (/?)  has 
moved  from  R'  to  0,  through  the  angle  R'  R  0.  The  axis  of  the 
non-deviating  eye  {L)  has  moved  through  an  equal  angle  (0  L  U). 


Fig.  205. 


P  o — 


— ~<o  0 


The  angular  movement  of  L,  as  measured  by  the  tape,  equals  the 
angular  deviation  of  R. 

Fig.  207  illustrates  the  measurement  of  a  divergent  strabismus 
of  the  right  eye.  The  hands  are  reversed,  but  the  principle  of 
course  is  the  same  as  before. 

Maddox's  tangent  scale,  and  Worth's  deviometer  in  which  an 
electric  light  is  flashed  on  the  cornea,  are  based  on  the  same  principle, 
and  are  very  useful,  the  latter  especially  so,  for  infants. 

The  graduated  tape  is  in  fact  a  substitute  for  a  graduated  arc 
of  a  circle,  and  represents  the  tangents  of  the  angular  deviations. 


In  this  mode  of  measurino-  a  strabismus  it  is  the  exci 


of  the 


51(> 


DISEASES    OF    THE    EYE. 


[chap.    XVII. 


fixing  eye  which  is  actually  measured,  aucl  the  excursion  of  the  de- 
viating eye  is  taken  to  be  equal  to  it.  If  the  excursions  of  the 
eyes  be  unequal,  that  is  to  say,  if  the  strabismus  be  not  a  con- 
comitant one,  the  result  is  faulty.  The  method,  though  difficult  to 
explain  in  woids,  is  quick  and  satisfactory  in  practice. 

3.  Perimeter  Method. — The  object  aimed  at  here  is  to  determine 
the  size  of  the  angle,  which  the  visual  axis  of  the  squinting  eye 
makes,  with  the  direction  it  should  normally  have.  For  this  pur- 
pose a  perimeter  is  employed.      Let  us  suppose  that  the  right  eye 


Fig.  208. 


{R,  Fig.  208)  be  the  squinting  eye,  and  that  P  o  P  be  the  arc  of  the 
perimeter.  The  patient  is  placed  at  the  instrument,  as  though  the 
field  of  vision  of  his  squinting  eye  were  about  to  be  examined.  He  is 
directed  to  look  at  a  distant  object  {A)  with  his  good  eye  (L).  The 
visual  line  from  B  should  now  pass  through  the  point  o,  but  it  passes 
through  the  point  n,  and  therefore  o  R  n  is  the  angle  of  the  strabis- 
mus. The  surgeon  finds  the  position  of  n  by  carrying  the  fiame  of  a 
candle  along  the  perimeter,  until,  with  his  eye  placed  behind  the 
flame,  he  finds  that  the  corneal  image  of  the  fiame  occupies  the 
centre  of  the  pupil.     The  fiame  itself  will  then  be  at  n,  and  the  size 


CHAP.  XVII.]  THE    ORBITAL   MUSCLES.  517 

of  the  squint-angle  may  be  read  off  there.  This  gives  the  optical 
axis  of  the  eye  ;  but,  to  be  strictly  accurate,  we  must  remember  that 
the  position  of  the  visual  axis  is  what  is  required,  and  that  it  lies  a 
few  degrees  farther  inwards,  according  to  the  size  of  the  angle. 

4.  Tangent  Strabismometer. — Maddox's  tangent  scale  can  be 
used  to  determine  the  angle  of  strabismus  subjectively,  by  means  of 
the  diplopia  if  it  be  present,  and  also  objectively,  by  the  observation 
of  the  corneal  reflex  ;  in  the  latter  respect  it  is  only  a  modification 
of  Priestley  Smith's  method.  The  scale  has  two  sets  of  figures, 
large  ones  for  a  distance  of  five  metres,  and  smaller  ones  for  a  distance 
of  one  metre.  At  the  centre,  or  zero  point,  a  candle  is  fixed,  and 
also  a  string  one  metre  long  for  adjusting  the  distance  of  the  patient. 
The  figures  on  one  side  of  the  zero  are  red,  and  on  the  other  black. 

When  diplopia  is  present,  the  patient  is  merely  asked  to  indicate 
the  figure  opposite  to  which  the  false  image  of  the  candle  appears. 

In  the  objective  method,  the  surgeon  stands  with  his  head  below 
the  zero  of  the  scale,  facing  the  patient ;  he  then  notes  the  eccentric 
position  of  the  corneal  reflex  of  the  candle  in  the  deviating  eye  ; 
and,  estimating  the  amount  of  the  squint,  directs  the  patient  to 
look  at  this  figure  on  the  scale.  If  the  estimate  be  correct,  the 
reflection  w411  be  in  its  proper  position  on  the  cornea  ;  if  it  be  not, 
the  patient  is  directed  to  look  at  other  figures  higher  or  lower,  as 
the  case  may  be,  until  the  position  of  the  reflex  is  correct. 

*  Mobility  of  the  Eye  in  Convergent  Concomitant  Strabismus. — 
In  cases  of  long  standing,  the  mobility  is  often  defective  in  the 
squinting  eye,  and  sometimes  also  in  the  fixing  eye.  The  method 
of  measuring  the  excursions  of  the  eyes  has  been  described  on 
p.  471.  In  strabismus  we  simply  compare  the  outward  mobility 
of  the  squinting  eye  with  that  of  the  good  eye,  to  ascertain  how 
much,  if  anything,  the  former  lacks  of  its  normal  amount. 

Before  undertaking  the  treatment  of  a  case  of  convergent 
strabismus,  in  addition  to  the  points  mentioned,  the  power  of 
fixation  of  the  squinting  eye,  the  presence  or  absence  of  diplopia 
and  the  sense  of  fusion,  the  refraction,  and  the  acuteness  of  vision, 
should  all  be  asceitained.  For  testing  the  vision  in  very  young 
children,  Worth  lias  suggested  ivoiv  balls  of  different  sizes  which 
are  thrown  on  the  floor  and  which  the  child  is  asked  to  pick  up. 

Treatment  of  Concomitant  Conveiyent  Strabis7)ms. — 

(a)  Optical  Treatment.     The  total  hypermetropia,  and  the  astig- 


518  DISEASES    OF    THE   EYE.  [chap.   xvii. 

matism,  if  any,  must  be  corrected,  and  the  glasses  must  be  worn 
constantly.  In  young  children,  atropine  must  be  used  to  determine 
the  refraction,  and  it  should  be  continued  until  the  glasses  have  been 
worn  for  some  time.  Some  sui-geons  order  glasses  for  infants  of 
twelve  months  or  even  less.  The  glasses  frequently  diminish  or 
remove  the  strabismus  while  being  worn.  They  act  by  removing 
the  strain  on  the  accommodation  and  also  by  improving  the  vision. 

(b)  Orthoptic  Treatment. — To  Javal  is  due  the  credit  of  devising 
this  method.  It  consists  in  preventing  the  development  of  amblyopia, 
and  in  training  the  sense  of  fusion.  To  attain  the  first  object,  com- 
plete occlusion  of  the  fixing  eye  for  a  certain  period  every  day  is 
necessary.  Instillation  of  atropine  in  the  fixing  eye  is  also  very 
serviceable  and  may  replace  the  bandage,  it  frequently  causes  the 
strabismus  to  change  over  to  this  eye,  especially  when  the  originally 
squinting  eye  is  used  for  near  vision.  When  the  vision  is  sufficiently 
improved,  the  training  of  the  fusion  sense  should  be  undertaken.  If 
diplopia  be  not  present  spontaneously  it  must  be  developed  ;  and 
it  is  usually  possible,  when  the  sight  in  the  squinting  eye  is  not  too 
defective,  to  give  the  patient  diplopia — i.e.  to  make  him  contin- 
uously conscious  of  the  presence  of  the  image  belonging  to  the 
squinting  eye.  This  may  be  done  by  means  of  exercises  with  a 
prism,  base  downwards,  before  the  deviated  eye,  or  by  coloured 
glasses,  and  with  a  candle  flame  used  as  visual  object.  The  exer- 
cises are  to  be  repeated  daily,  until  diplopia  without  a  prism  is 
established. 

Double  vision  having  been  established,  we  proceed  to  enable  the 
patient  to  fuse  the  double  images. — i.e.  to  obtain  binocular  vision — 
by  exercises  with  the  stereoscope,  convenient  forms  of  which  are 
Priestley  Smith's  heteroscope,  and  Worth's  amblyoscope,  or  a  modi- 
fication of  the  latter,  in  which  the  electric  illumination  of  the  images 
can  be  varied  at  will.  The  training  of  the  fusion  sense  should  be 
carried  out  during  that  time  of  life  which  is  the  period  of  normal 
development  of  this  sense.  After  six  years  of  age  the  results  are 
unsatisfactory,  and  involve  great  trouble  and  patience,  yet  cases 
have  been  recorded  recently  in  which  binocular  vision  has  been 
restored  i?i  ])atients  of  9  and  10  years  of  age. 

As  the  patients  are  children,  simple  images,  which  require  mere 
superposition  without  recognition  of  the  third  dimension,  are  gener- 
;illv  siilliciciit    at    liist  ;    latci'  on.  ])ictures  of  geometrical    drawings 


CHAP.  XVII.]  THE   ORBITAL    MUSCLES.  519 

involving  perspective  can  be  used.  Worth,  however,  believes  that 
this  treatment  should  be  carried  out  by  the  surgeon,  and  that  a 
child  old  enough  to  carry  out  stereoscope  exercises  himself  is  far 
past  the  age  when  the  fusion  sense  might  have  been  developed. 
This  method  of  treatment  is  useful,  too,  in  completing  the  cures 
which  have  been  commenced  by  operative  measures.  But  the 
method  makes  great  demands  on  the  patience  and  intelligence  both 
of  the  patient  and  of  his  parents. 

(c)  Operative  Treatment. — According  to  some,  operative  pro- 
cedures should  not  be  undertaken,  unless  fusion  training  has  failed, 
or  is  too  slow  and  tedious,  while  the  majority  of  surgeons  still  depend 
mainly  on  operative  treatment,  with  or  without  the  aid  of  the  orth- 
optic method.  Opinions  differ  as  to  the  best  age  for  operation,  the 
majority  of  surgeons  preferring  to  wait  until  the  patients  are  over 
five  or  six  years  of  age,  while  those  who  have  studied  the  subject 
from  the  orthoptic  side  consider,  that  when  an  operation  is  indi- 
cated, the  earlier  it  is  done  the  better. 

Since  concomitant  strabismus  is  the  result  of  faulty  innervation, 
and  not  a  muscular  defect,  rules  which  will  ensure  in  every  case, 
with  absolute  certainty,  the  desired  degree  of  operative  effect 
cannot  be  laid  down.  Indeed,  all  that  is  required  in  those  cases  in 
which  binocular  vision  can  be  established  is  an  approximate  correc- 
tion, as  the  patient's  fusion  sense  w411  complete  the  cure. 

Formerly  the  operations  in  use  consisted  in  tenotomy  of  one  or 
both  internal  recti,  supplemented  if  need  be  by  advancement  of  the 
external  recti.  But  within  the  past  few  years  advancement  of  the 
external  recti  has  begun  to  take  the  place  of  tenotomy  of  the  internal 
recti,  which  has  been  almost  completely  abandoned  by  many  sur- 
geons. As  Landolt  pointed  out  years  ago,  the  disadvantages  of 
tenotomy  are  serious.  Tenotomy  of  the  internal  rectus  by  allowing 
the  eye  to  come  slightly  forwards  and  the  muscle  to  retract,  weakens 
the  power  of  convergence,  and  to  a  less  degree  the  power  of  lateral 
movement,  without  producing  any  increase  of  mobility  in  the  op- 
posite direction.  Again,  even  when  no  over-correctioii  of  the  stra- 
bismus is  produced  by  the  operation,  the  eye  after  some  years  often 
becomes  divergent.  Advancement  of  the  external  recti,  on  the  other 
hand,  keeps  the  eye  back  in  the  grip  of  the  muscles  ;  and,  while  it 
increases  the  outward  mobility,  it  does  so  without  weakening  the 
internal   recti,   in   fact  the  total   range   of  movement   is  enlarged. 


520  DISEASES    OF    THE   EYE.  [chap.  xvii. 


Furthermore  there  is  little  or  no  danger  of  over-correction,  as  long  as 
the  operation  is  not  combined  with  tenotomy  of  the  internal  recti. 
If  a  double  advancement  should  still  leave  a  convergent  strabismus 
of  say  15°  or  more,  then  a  careful  tenotomy  limited  to  the  tendon 
alone,  without  interfering  with  its  lateral  capsular  attachments,  may 
be  performed  or  the  muscle  may  be  lengthened  (p.  521). 

Operations  for  Strabismus.  —  Tenotomy.  —  The  instruments 
required  for  this  operation  are  a  spring-stop  speculum,  a  small- 
toothed  forceps,  blunt  scissors  somewhat  curved  on  the  flat,  and 
two  strabismus  hooks  (Fig.  209). 

The  eye  having  been  thoroughly  cocainised,  and  a  few  drops  of 
2   per  cent,   cocaine  solution  injected   under  the   con- 

rjunctiva  over  the  site  of  the  tendon,  the  patient  is 
placed  on  his  back,  the  surgeon  standing  in  front  of 
him  and  on  his  left  side,  if  the  left  eye  is  to  be  operated 
on,  or  behind  him  if  it  be  the  right  eye.  The  speculum 
is  then  applied,  and  the  conjunctiva  over  the  insertion 
of  the  tendon  of  the  internal  rectus  is  seized  with  the 
forceps,  and  incised  with  the  scissors  between  the  for- 

tceps  and  the  eye.  Into  the  opening  thus  made  the 
points  of  the  closed  scissors  are  inserted,  and,  with  a 
snipping  action,  a  passage  is  made  through  the  sub- 
conjunctival tissue,  from  the  conjunctival  opening  to 
Fig  209  ^^^  upper  border  of  the  tendon  in  case  of  the  left  eye, 
or  to  its  lower  border  in  the  right  eye.  The  scissors 
are  now  laid  aside,  but  the  conjunctiva  is  still  held  in  the  forceps ; 
and,  with  the  right  hand,  the  point  of  the  hook  is  passed 
through  the  opening  and  along  the  passage  until  the  edge  of 
the  tendon  is  reached.  The  point  of  the  hook  being  kept  in 
contact  with  the  sclerotic,  the  instrument  is  then  turned  rapidly 
round  and  under  the  tendon,  and  is  brought  close  up  to  the  insertion 
of  the  latter  into  the  sclerotic,  care  being  taken  that  the  whole 
breadth  of  the  tendon  lies  on  the  hook.  The  forceps  are  now  laid 
aside,  and  the  hook  carrying  the  tendon  is  transferred  to  the  left 
hand.  One  blade  of  the  scissors  (held  in  the  right  hand)  is  now 
inserted  between  the  globe  and  the  tendon,  and  the  latter  is  com- 
pletely divided  at  its  insertion.  It  is  better  to  cut  towards  the 
handle  of  the  hook  than  away  from  it,  as  there  is  then  no  tendency 
to  push  any  fibres  of  the  muscle  off  the  hook.     The  second  hook  is 


CHAP.  XVII.]  THE    ORBITAL   MUSCLES.  521 


then  employed  for  searching,  above  and  below,  for  any  strands  of 
the  tendon  which  may  be  left  undivided,  the  test  for  complete 
division  being  that  the  hook  can  be  brought  up  without  obstruction 
to  the  margin  of  the  cornea.  If  even  a  small  segment  of  the  tendon 
be  left  undivided,  the  result  of  the  operation  is  apt  to  ])e  unsatis- 
factory. Immediately  after  the  operation,  a  marked  diminution 
in  the  mobility  of  the  eye  inwards  should  be  looked  for,  as  this 
motion  can  now  only  take  place  by  aid  of  any  remaining  connective 
tissue  attachments  of  the  muscle  to  the  eyeball  and  capsule  of  Tenon. 
If  this  defect  in  motion  be  not  present,  or  to  only  a  slight  degree 
in  comparison  with  the  supposed  extent  of  operation,  it  may  be 
concluded  that  the  tendon  is  imperfectly  divided,  and  a  new  search 
Avith  the  hook  for  undivided  filaments  must  be  made.  To  estimate 
this  loss  of  motion  it  is  necessary  before  the  operation  to  note  the 
degree  of  mobility  of  the  eyeball  inwards,  and  to  compare  it  with 
the  inward  motion  of  the  other  eye. 

The  effect  of  the  operation  may  be  diminished,  if  necessary,  by 
drawing  the  edges  of  the  conjunctival  wound  together  with  a  vsuture, 


'oUlgTi 


b 

1  2 

Fig,   210. — Method  of  lengthening  a  tendon  (Harmau). 

the  tendon  being  thus  prevented  from  uniting  with  the  globe  so  far 
back.  A  better  way  to  limit  the  effect  of  a  tenotomy  is  to  pass 
a  suture  through  the  tendon,  as  if  for  an  advancement,  and  tie  it 
loosely  so  as  to  allow  the  divided  tendon  to  retract  by  the  desired 
amount   only,   or  to  lengthen   the   tendon   by  partial   incisions   as 


tH-- 


b 

1  2 

Fig.     211. — Method  of   lengthening  a  tendon  combined   with    a    vertical 
displacement  (Harman). 

shown  in  Fig  210.  The  incisions  at  a  and  a'  are  limited  to  half 
the  lu'eadth  of  the  tendon,  while  the  intermediate  incision  at  h 
takes  in  two-thirds.     If  it  be  desired  to  produce  a  vertical  deviation 


DISEASES    OF    THE    EYE.  [chap.   xvii. 


as  well  as  the  horizontal  effect,  the  incisions  should  be  made  as  in 
Fig.  211,  whicli  will  allow  of  an  upward  displacement ;  if  a  downward 
displacement  l)e  ref|uired,  the  section  h  should  ])e  placed  nearer 
to  the  insertion  than  a. 

Conjmictival  sutures  should  also  he  used  when  an  extensive 
loosening  of  the  sub-conjunctival  tissue  has  ))een  performed,  in  order 
to  prevent  sinking  of  the  caruncle  or  the  formation  of  a  granuloma 
on  the,  otherwise  exposed,  sclera. 

The  8ub-conjunctival  Operation  for  Strabismus  is  performed  as 
follows  : — A  fold  of  conjunctiva  is  seized  close  to  the  lower  margin 
of  the  insertion  of  the  muscle,  and  incised  with  blunt-pointed 
scissors,  so  as  to  expose  the  tendon.  A  strabismus  hook  is  passed 
through  the  opening  and  under  the  tendon.  The  scissors  are  now 
inserted  and  opened  slightly,  one  point  being  kept  close  to  the  hook, 
while  the  other  is  passed  between  the  tendon  and  the  conjunctiva, 
and  the  tendon  is  divided  at  its  insertion.  This  method  is  very 
generally  adopted  by  English  surgeons,  but  that  of  von  Grsefe. 
previously  described,  is  preferable,  as  it  much  more  readily  admits 
of  modifications  of  the  effect. 

In  von  Arlt's  Method,  instead  of  a  hook  being  passed  under  the 
tendon  in  the  first  instance,  the  latter  is  seized  with  the  forceps  with 
which,  just  2:)reviously,  the  conjunctiva  had  been  raised.  In  other 
respects  the  proceeding  is  the  same  as  von  Grsefe's,  than  which  it 
is  said  to  be  less  painful. 

The  immediate  and  ultimate  effects  of  a  tenotomy  are  by  no  means 
identical.  Immediately  after  the  operation  the  effect  is  marked, 
owing  to  the  loosening  of  the  tendon  from  its  insertion.  In  a  few 
days,  when  the  tendon  becomes  re-attached,  the  effect  diminishes, 
and  in  the  course  of  some  w^eeks  there  is  again  an  increase  in  the 
effect,  and  this  increase  continues  for  about  a  year,  as  above  stated. 

The  ultimate  result  may,  with  tolerable  certainty,  be  estimated 
immediately  after  the  operation  by  testing  the  power  of  convergence. 
If  the  patient  be  directed  to  look  with  both  eyes  at  the  surgeon's 
finger  held  in  the  middle  line,  and  it  be  approached  to  within  12  or 
15  cm.  of  his  nose,  and  if  the  convergence  of  the  eyes  can  be  main- 
tained at  that  distance,  the  effect  will  not  be  too  great.  But  if,  at 
a  distance  of  from  18  to  20  cm.,  the  operated  eye  should  cease  to 
converge,  or  ])egin  to  diverge,  or  if  even  at  12  cm.  the  convergence, 
although  accomplished,  cannot  be  maintained  for  more  than  a  few 


CHAP.  XVII.]  THE   ORBITAL   MUSCLES.  523 

moments,  and  that  then  the  operated  eye  deviate  outwards,  ultimate 
divergence  may  be  expected,  even  thouoh  the  actual  position  of  the 
visual  axes  be  correct.  A  restricting-  suture  nuist  be  applied  in  such 
cases. 

Sometimes,  although  tlio  patient  converties  up  to  12  cm.  satis- 
factorily, and  maintains  the  convergence  at  that  distance  for  some 
moments,  the  eye  will  then  rotate  inwards.  In  such  cases  there  is 
apt  to  be  a  recurrence  of  the  strabismus. 

Advancement. — An  opening  is  made  with  scissors  in  the  con- 
junctiva immediately  over  the  insertion  of  the  external  rectus,  and 
as  long  as  the  breadth  of  the  tendon.     The  band  of  conjunctiva 


Fig.  212. 

between  the  opening  and  the  cornea  is  separated  up  with  the  scissors 
from  the  sclerotic,  for  to  it  the  tendon  has  to  be  fastened  later  on.  A 
strabismus  hook  is  now  passed  under  the  tendon,  and  brought  well 
up  to  its  insertion,  care  being  taken  that  the  whole  width  of  the 
tendon  is  held  on  the  hook.  A  needle  carrying  a  fine  silk  suture  is 
introduced  from  its  uj^per  margin  between  the  tendon  and  sclerotic, 
and  passed  through  the  tendon  at  its  middle  line.  In  the  same  way 
another  suture  is  passed  behind  the  tendon  from  its  lower  margin, 
and  through  it,  close  to  the  first  suture.  Each  of  these  sutures  is 
knotted  firmly  on  the  tendon,  a  long  end  being  left  to  each  suture 
(Fig.  212).  The  tendon  is  separated  off  with  the  scissors  from  the 
sclerotic  close  to  its  insertion.      Tlie  sutui'es  are  passed  through  the 


524  DISEASES    OF    THE   EYE.  [chap.  xvii. 

conjunctival  flap  in  the  direction  of  the  muscle,  and  are  respectively 
tied  with  their  own  ends.  In  order  to  obtain  a  better  hold  for  the 
sutures  some  fibres  of  the  sclerotic  parallel  to  the  corneal  margin 
should  be  taken  up  on  the  needle,  but  this  must  be  done  with  great 
care  and  with  strict  asepsis.  A  greater  or  less  effect  is  produced, 
according  as  the  sutures  are  placed  farther  or  nearer  to  the  insertion 
of  the  tendon,  and  according  as  they  are  drawn  more  or  less  tightly. 
The  effect  can  also  be  increased  by  excision  of  a  portion  of  the  tendon 
previous  to  suturing,  and  subsequent  adhesion  of  the  advanced 
tendon  can  be  favoured  by  gently  scraping  the  sclera  and  under 
surface  of  the  tendon  before  the  sutures  are  fastened. 

There  are  many  modifications  of  the  advancement  operation. 
Some  of  them  consist  in  different  methods  of  applying  the  sutures. 
Some  operators  merely  make  a  tuck  or  reef  in  the  tendon  without 
dividing  it,  others  divide  the  tendon  longitudinally  and  suture  each 
portion  separately  above  and  below  the  corneal  margin.  In  capsular 
advancement  the  muscle  is  advanced  along  with  the  capsule  of 
Tenon,  the  tendon  being  folded  over  on  itself  when  the  sutures  are 
tied.  We  have  tried  many  of  these  methods,  and  find  the  above 
described  operation  as  reliable  as  any.  One  advantage  of  the 
tucking  operation  is  that  if  the  sutures  should  give  way  the  strabis- 
mus will  not  be  made  worse  ;  but  none  of  the  methods  of  folding 
or  tucking  a  tendon  produce  as  great  an  effect  as  the  operation 
just  described. 

After  a  tenotomy,  a  light  dressing  and  bandage  are  applied  on 
the  operated  eye  only,  but  in  cases  of  advancement,  even  if  but  one 
eve  has  been  operated  on,  the  bandage  should  be  applied  to  both, 
and  should  not  be  removed,  except  for  dressing  purposes,  for  several 
days. 

Dangers  of  the  Strahismus  Operation.  —  Severe  inflammatory 
reaction  after  a  strabismus  operation  is  very  rare,  and  should  not 
occur,  even  after  an  advancement.  Puncture  of  the  sclerotic  with 
the  scissors  while  the  tendon  was  being  divided  has  occurred  in  the 
hands  of  some  operators  ;  but  except  with  sharp-pointed  scissors, 
or  want  of  care,  this  cannot  occur.  It  is  also  stated,  that  eyes  have 
])een  lost  after  squint  operations  througli  orbital  cellulitis,  which, 
beyond  doubt,  must  have  been  ])rought  about-  l)v  the  introduction 
of  sceptic  matter  upon  the  instruments. 

Occasionally,  a  small  artei'ial  lu'anch  may  be  (li\idcd  during  the 


fHAP.   XVII.]  THE    ORBITAL   MUSCLES.  525 

operation,  and  this,  bleeding  into  the  capsule  of  Tenon,  may  cause 
rather  alarming  exophthalmos.  The  protrusion  goes  back  in  a  few- 
days  with  use  of  a  pressure  bandage. 

Sinking  of  the  caruncle,  some  months  after  the  tenotomy,  when 
it  does  occur,  can  ])e  remedied  in  the  following  way  : — The  con- 
junctiva is  divided  vertically  about  6  mm.  from  the  caruncle.  The 
inner  lip  of  the  wound  is  raised,  scissors  curved  on  the  flat  passed 
in,  and  the  sub-conjunctival  tissue  as  far  as  under  the  sunken 
caruncle  sej^arated.  The  sub-conjunctival  tissue  under  the  outer  lip 
of  the  wound,  and  as  far  as  the  corneal  margin,  is  loosened  in  the 
same  way,  and  the  two  flaps  are  brought  together  with  a  suture, 
which  includes  a  sufficiency  of  conjunctiva  to  draw  the  caruncle  well 
forwards. 

Treatment  subsequent  to  Oferation. — It  is  generally  necessary  for 
the  patient  to  wear  the  correcting  spectacles  for  his  hypeimetropia 
either  constantly  or  for  near  vision  only,  according  as  the  result  of 
the  operative  measures  makes  it  more  or  less  desirable  to  suspend 
the  accommodation.  After  some  months,  it  is  usually  possible  to 
leave  off  the  spectacles,  except  for  near  vision. 

A  cure  of  the  strabismus,  in  the  sense  of  removal  of  the  deformity, 
can  be  attained  by  operation,  and  by  itself  affords  ample  indication 
for  the  operation.  But  a  cure,  in  the  true  sense  of  the  term,  involves 
restoration  of  binocular  vision,  and  this  is  very  rarely  obtained  by 
operative  measures  alone.  To  this  end  the  operation  must  be 
followed  up  by  orthoptic  treatment  as  already  described  (p.  518). 

Divergent  Concomitant  Strabismus. — This  form  of  strabismus 
is  not  so  common  as  convergent  squint.  Two-thirds  of  the  cases 
are  due  to  myopia,  which  is  generally  more  than  5  or  6D.  It  also 
occurs  apart  from  myopia,  and  is  then  most  frequently  neuropathic. 

In  myopia  two  causes  contribute  to  weaken  the  power  of  con- 
vergence for  near  vision.  In  the  first  place,  little  or  no  accommoda- 
tion is  required,  and  hence  a  tendency  exists  to  relax  the  conver- 
gence. Furthermore,  when  the  working  distance  is  too  close  to 
the  eyes,  the  increased  effort  of  convergence  which  is  necessary  can- 
not always  be  maintained.  At  first  the  weakness  of  convergence 
manifests  itself  only  in  near  vision  (insufficiency  of  convergence), 
but  later  on  it  results  in  absolute  divergence  for  distance.  Myopic 
divergent  squint  makes  its  appearance  later  in  life  than  convergent 
squint,  and  the  fusion  sense  is  better  developed  than  in  the  latter. 


520  DISEASES   OF    THE   EYE.  [cuw.  xvit. 

Neuropathic  divergent  .squint,  on  the  other  hand,  is  chiefly  con- 
genital, and  the  fusion  sense  is  defective  or  absent.  The  degree  of 
divergence  is  very  liable  to  vary  from  time  to  time  in  these  cases. 

Trcalmcnt. — The  correction  of  the  myopia,  by  establishing  the 
proper  relations  between  accomniodation  and  convergence,  will  cure 
the  divergence  in  recent  cases  (see  Insufficiency  of  Convergence, 
p.  534).  The  glasses  should  be  worn  constantly.  In  other  cases, 
advancement  of  one  or  both  internal  recti  should  be  performed,  with 
tenotomy  of  the  external  recti  if  the  power  of  abduction  be  greater 
than  normal. 

Non-paralytic  divergent  stral)ismus  also  occurs  in  blind  eyes, 
and  in  high  myopia.  In  the  high  degrees  of  myopia  the  movements 
of  the  eyes  are  more  or  less  impaired,  owing  to  their  egg-shaped 
elongation.  When  the  vision  of  one  eye  becomes  defective,  or  when 
it  becomes  blind,  there  is  always  a  tendency  to  divergence,  unless 
the  other  eye  be  hypermetropic.  If  one  eye  be  myopic  and  the 
other  emmetropic,  the  myopic  eye  is  often  used  for  near  vision,  and 
then  the  other  eye  diverges,  whereas  the  emmetropic  eye  serves  for 
distance,  and  the  myopic  eye  may  then  be  divergent. 

*  Latent  Deviations  (Heterophoria).— When  the  orbital  muscles 
are  in  a  state  of  normal  equilibrium,  or  orthophoria,  and  the  eyes 
are  fixing  an  object  either  distant  or  near,  if  one  eye  be  covered^  and 
thus  excluded  from  the  act  of  vision,  it  nevertheless  continues  to 
maintain  its  direction,  and  little  or  no  deviation  of  the  eye  takes 
place  ])ehind  the  screen,  or  covering  hand.  But  if  the  muscular 
balance  be  imperfect  (heterophoria),  there  is  a  tendency  for  the 
eyes  to  deviate  from  the  correct  position,  which  tendency,  however, 
under  ordinary  conditions,  is  kept  in  check  by  the  desire  for  single 
vision.  The  deviation  is  suppressed  by  a  special  muscular  effort, 
and  only  becomes  manifest  under  artificial  conditions  ;  namely, 
when  the  vision  of  the  two  eyes  is  dissociated,  by  such  measures  as 
render  binocular  vision  difficult  or  impossible.  This  form  of  deviation 
is  therefore  said  to  be  latent,  and  is  sometimes  known  as  suppressed 
squint. 

Latent  deviations,  due  to  disturbance  of  the  relation  between 
accommodation  and  convergence,  occurring  in  errors  of  refraction 
(such  as  latent  convergence  with  hypermetropia),  are  not  to  be 
regarded  as  heterophorias  unless  they  persist  after  the  optical 
correction. 


CHAr.  xviT.]  THE    ORBITAL    MUSCLES. 


If  the  fusion  sense  become  impaired — by  disease  of  one  eye, 
for  example — a  latent  deviation  may  become  manifest  and  may 
lead  to  true  strabismus. 

Latent  deviations  may  be  in  the  direction  of  convergence 
(Esophoria),  or  divergence  (Exophoria),  or  the  eyes  may  tend  to 
turn  in  opposite  directions  vertically,  one  eye  being  higher  than 
the  other  (Hyperphoria),  when  the  condition  is  called  right  or  left 
hyperphoria,  according  to  the  eye  which  is  the  higher. 

Anaphoria  (latent  upward  deviation  of  both  eyes)  and  Kata- 
phoria  (latent  downward  deviation  of  both  eyes)  are  much  rarer 
conditions. 

The  muscular  effort  necessary  to  keep  the  tendency  to  deviation 
in  control,  sometimes  leads  to  the  development  of  asthenopic 
symptoms  (muscular  asthenopia).  Special  attention  has  been  paid 
to  this  form  of  '  eye  strain '  in  the  United  States,  where  it  has 
been  held  accountable  for  nervous  affections,  such  as  neurasthenia, 
hysteria,  migraine,  chorea,  and  epilepsy.  This  view,  however,  is 
generally  regarded  as  somewhat  exaggerated.  It  is  more  probable 
that  heterophoria  merely  acts  as  an  additional  exciting  cause  of 
nervous  attacks,  in  those  who  are  already  subject  to  the  conditions 
mentioned.  Defects  in  the  muscular  balance  are  not  more  common 
in  neuropathic  than  in  healthy  individuals,  who  do  not  suft'er  from 
asthenopia  ;  and  these  defects  may  be  present  in  the  former, 
without  giving  rise  to  asthenopia. 

Test  for  Latent  Deviations. — The  best  test  object  for  distance 
(six  metres)  is  a  candle  flame  or  frosted  electric  lamp,  and  for 
near  vision  a  black  dot  or  line. 

1.  Test  by  Exclusion  of  One  Eye. — While  the  eyes  flx  the  test 
object,  one  eye  is  covered  by  the  surgeon's  hand,  and  its  position, 
as  shown  for  instance  by  the  corneal  reflex,  is  observed  immediately 
on  withdrawing  the  hand,  as  also  any  movement  which  the  eye  mav 
make  to  right  itself.  The  latter  movement  indicates  a  deviation 
in  the  opposite  direction — e.g.  if  the  eye  move  inwards  on  being 
uncovered,  it  must  have  been  deviated  outwards  when  covered.^ 
Both   eyes  must  be   examined  alternately.     AVhen   a  heterophoria 

1  In  the  '  exclusion  '  test  for  latent  deviations  it  will  be  observed  that 
it  is  the  position  of  the  eye  which  is  covered  which  is  noted  by  the  surgeon, 
whereas  when  the  '  exclusion  '  test  is  applied  to  detect  a  manifest  stra- 
bismus (p.  472)  the  uncovered  eye  must  be  watched. 


r)28 


DISEASES   OF    THE   EYE. 


[chap.    XVII. 


is  present,  it  generally  exists  in  both  eyes,  and  is  of  the  same  kind. 
In  hyperphoria  (vertical  deviation),  the  eye  which  is  higher  will 
rotate  downwards,  and  its  fellow  will  make  a  movement  upwards  ; 
for  example,  in  left  hyperphoria  the  left  eye  will 
deviate  upwards  when  covered,  and  will  adjust  itself 
by  a  downward  movement  when  uncovered  ;  the 
right  eye,  on  the  other  hand,  when  screened  will 
deviate  downwards,  and  will  rotate  upwai'ds  on  re- 
^  exposure.     This   test,  however,   is   by  no  means  so 

I  delicate  as  the  following  subjective  tests,  which  de- 

I  pend  on  the  production  of  diplopia. 

I  2.  Tests  with    Prisms.— {a)    This   test 

was  first  used  by  von  Graefe  for  the  ex- 
amination of  insufficiency  of  the  internal 
Fig.  213.        recti.     A  prism  is  placed  vertically  before 
one  eye,  of  such  a  strength  that  it  cannot 
be  overcome  by  the  muscles  ;   one   of   10°  is  sufficient. 
A  dot  with  a  fine  line  drawn  veitically  through  it  (Fig. 
213)  on  a  sheet  of  white  paper  is  given  to  the  patient 
to  look  at,  at  his  usual  reading  distance.     If  the  prism 
be  placed  with  its  base  downwards  before  the  right  eye, 
this,  in  the  normal    condition,  both   eyes  fixing, 
would  produce  a  double  image  of  the  dot  and  line, 
placed  of  course  vertically,   one   over   the    other, 
and  as  the  images  of  the  lines  overlap,  the  figure 
would  seem  to  be  a  line  with  two  dots,  the  upper 
dot  being  the  image   belonging  to  the   right  eye 
(Fig.  214).     In  insufficiency  of   convergence   (ex-   fjg.  215. 
ophoria),  the  image   of   the   right  eye  would  not 
only  be  higher  than  that  of  the  left,  but  it  would  also  stand 
to   the   left   (crossed   double   images)  more   or  less  ;    so  that 
here  the  picture   is  that  of  two  lines,  each  with  a  dot,  the 
upper  line  and  dot  standing  to  the  left  side  (Fig.  215).     This 
crossed    diplopia    indicates    divergence.      In    this    case    the 
artificially  produced  vertical  diplopia  renders  the  latent  de- 
viation manifest,  and  a  lateral  diplopia  is  superadded. 

In  order  to  test  for  vertical  deviations  (hyperphoria),  the 
prisms  must  be  placed  liorizontally,  and  with  their  bases  inwards  ; 
because  the  external  being  much  weaker  than  the  internal   recti, 


Fig. 
214. 


f'HAP.    XVTT. 


T?IE    OnniTAL    MUSCLES. 


520 


prisuis  of  low  er  degrees  can  be  used  ;  but  for  this  purpose  the  rod 
test  described  below  is  better. 

(b)  Stevens'  phorometer  (Fig.  216)  is  a  convenient  instrument 
for  applying  the   prism   tests.     The   prisms  can   be  placed  either 


Fig.  216. — The  prisms  of  Stevens'  phorometer. 

vertically  or  horizontally  by  the  lever,  and  the  degree  of  hetero- 
phoria  can  be  measured  by  a  rotation  of  the  prisms,  the  amount 
of  the  deviation  being  indicated  on  the  scales  to  the  right  and  left, 
(c)  Maddox's  Double  Prism  is  also  useful.  It  is  composed  of 
two  prisms,   base  to  base,   and  is  easily  adjusted.     When  placed 


Fig.  217. 


vertically  before,  say,  the  right  eye,  with  the  line  of  junction  of 
the  prisms  opposite  the  pupil,  this  eye  sees  two  images  of  the  spot, 
one  vertically  over  the  other,  and,  if  the  muscular  equilibrium  be 
normal,  the  spot  seen  by  the  left  eye  will  appear  to  be  in  a  line  with 
34 


-)30 


Dr. LEASES    OF    THE    EYE. 


{CUXV.     XVTT. 


the  other  two.  and  midway  between  them  (Fig.  217).     If  a  hori- 
zontal line  be  used  as  the  test  object,  the  different  forms  of  hetero- 


phoria 


can 

be 

dia 

gnosed 

by 
R 

L 

n 

the  position  of  the  central 


Inie  seen 
-R 


R 


Fio.  21S.— \< 


Fto.   21!).- — Ki<2;lit   hypcrijlioria  and 
osoplK>rin. 


l)y  the  left  eye,  with  reference  to  the  two  lines  seen  ))y  the  rioht — 
e.g.,  Fig.  218  indicates  normal  e(|uilii)rium,  and  Fig.  219  right  hyper- 
phoria and  esophoria. 

3.  Maddox's  Rod  Test.— This  is  probably  the  ])est  test.  The 
apparent  lengthening  of  a  flame  into  a 
line  of  light,  when  looked  at  through  a 
strong  cylinder,  is  utilised  to  make 
the  two  images  so  dissimilar,  that  no 
desire  to  unite  them  remains.  The 
chief  advantage  of  this  principle  is 
that  slight  malpositions  do  not,  as 
with  prisms,  vitiate  the  result  mate- 
rially. The  instrument  consists  of  a 
number  of  parallel  glass  rods  (Fig.  220) 
usually  coloured  red,  which  thus  pro- 
at  right  angles  to  the  axis  of  the  rods. 


Fig.  220.— Maddox's  Rods. 


duce  a  red   line  of  lisht, 


when    2)laced  [before   one   of   the    eyes,  the    other   eye   seeing   the 


Fio.   221. —  1.  Orthoplioiia.      2.  Exophoria  or  latent  divergence. 
.'J.   Esoi)horia  or  latent   convergence. 

light  or  flame  naturally.     When  the  red  line  passes  through  the  flame 
there  is  orthophoria  (Fig.  2lM  .  1). 


riTAP.  xvTT.l  THE    ORBITAL    ^r^'SrLES.  .-»31 

The  line  of  light  iiiu.st  be  vertical,  and  tlierelore  the  rods  must  be 
placed  horizontally  for  horizontal  deviations  (Fig.  221),  and  the 
opposite  way  lor  vcitical  deviations  (Fig.  222).  The  defect  is 
measured  by  the  deviating  angle  of  that  prism,  which  brings  the 
light  and  line  together,  or,  preferably,  by  a  tangent  scale,  placed 
with  its  zero  just  behind  the  flame,  so  that  the  figure  crossed  by 
the  line  of  light  gives  the  deviation  in  degrees.  For  vertical  diplopia 
the  scale  should  be  vertical,  and  for  horizontal  diplopia,  horizontal. 
In  either  case  the  axis  of  the  cylinder  should  be  parallel  to  the  scale. 
When  the  cylinder  is  vertical,  it  should  be  shaded  from  the  light  of 
the  window.  By  placing  the  patient's  head  in  different  positions, 
the  diplopia  can  be  measured  in  all  parts  of  the  oculo-motor  field. 
Maddox's  vertical  and  horizontal  scales  should,  for  this  purpose, 
be  fixed  on  the  wall,  with  the  flame  or  electric  lamp  at  the  zero 
point.     This  test  is  most  useful  for  distant  vision  (6  metres). 


Fig.  222. — 1.  Orthophoria.     2.  Left  hyperphoria.      3.  Right  hyperphoria. 

4.  Maddox's  Wing  Test. — This  is  a  very  simple  and  useful  test 
for  measuring  horizontal,  vertical,  and  cyclophoric  deviations  with- 
out prisms  at  reading  distance.  The  patient  looks  through  the  slits 
in  the  eye-pieces  at  E  (Fig.  223).  The  horizontal  wing  R  covers  the 
upper  half  of  the  field  of  the  right  eye,  and  the  wing  L  the  lower 
half  of  the  left  field,  so  that  the  right  eye  sees  the  arrow  on  the  plate 
S,  while  the  left  eye  sees  the  scale  towards  which  the  arrow  points. 
For  vertical  deviations  a  vertical  scale  with  a  horizontal  arrow  is 
used,  and  the  pillar  P  is  rotated  so  that  the  wings  are  turned  longi- 
tudinally, out  of  the  way,  and  the  median  vertical  screen  then 
blocks  out  the  arrow  from  one  eye  and  the  figures  from  the  other. 
If  vision  be  defective  in  one  eye  a  movable  metal  arrow  is  provided 
which  can  be  moved  along  the  upper  part  of  the  screen  until  it 
appears  to  the  patient  to  be  pointing  at  the  white  arrow,  the  number 


-)32  DISEASES    OF    THE   EYE.  [chap.   xvii. 

or  letter  on  the  scale  to  wliicli  the  metal  arrow  points  can  then  be 
read  off.     We  have  found  this  a  very  useful  and  simple  instrument. 
In  order  to  obtain  accurate  results  when  testing  the  muscular 
balance,  any  error  of  refraction  must  be  corrected. 


Fig.   22.3. — Maddox's  Wing  Test  for  Heterophoria. 

*  Symptoms  oj  Heterophoria. — Great  difference  of  opinion  exists 
as  to  the  frequency  with  which  heterophoria  gives  rise  to  asthenopia. 
In  the  United  States  it  is  said  to  be  very  common.  There  is  no  doubt 
that  heterophoria  may  be  present  without  causing  any  incon- 
venience. Hyperphoria  is  the  most  troublesome  form,  esophoria  the 
next  most  troublesome,  while exophoria,unlesscombined  with  a  dimin- 
ished amplitude  of  convergence,  causes  little  or  no  annoyance.  The 
symptoms  are  :  headache  and  pains  in  the  eyes — especially  towards 
the  end  of  the  day,  or  following  on  long-continued  close  observation 
— giddiness  and  conjunctival  hyperemia.  Narrowing  of  the  pal- 
pebral fissure  sometimes  occurs  in  hyperphoria,  in  the  eye  which 
deviates  upwards. 

Treatment. — This  will  depend,  not  merely  on  the  degree  of  the 
heterophoria,  but  also  on  the  strength  of  the  muscles,  as  measured 
by  their  power  of  overcoming  the  diplopia  produced  by  prisms. 
Whether  the  heterophoria  be  present  in  near,  or  in  distant  vision, 
or  in  both  must  also  be  considered.     In  near  vision  at  a  distance  of 


CHAP.  XVII.]  THE   ORBITAL    MUSCLES.  533 

12"  an  exophoria  of  2°  to  4°  is  very  common,  and  often  causes  no 
annoyance. 

The  treatment  consists  in  the  wearing  of  prisms  with  the  base 
in  the  direction  of  the  muscle  to  be  relieved  (p.  400),  exercises  with 
prisms,  or  operation.  The  first  two  will  suffice  in  moderate  degrees 
of  the  defect ;  but  it  may  be  mentioned  that  the  value  of  exercises 
with  prisms  is  doubted  by  some  surgeons.  When  only  a  prism  of 
low  degree  is  required,  the  desired  effect  may  be  accomplished  l)y 
decentration  of  the  lenses  (p.  412),  which  correct  the  error  of  re- 
fraction, if  there  be  one.  In  the  higher  degrees  operation  may  be 
necessary,  advancement  of  a  muscle  being  preferred  to  tenotomy  of 
the  antagonist.  In  Europe,  graduated  tenotomies,  by  which  is 
meant  partial  division  of  the  fibres  of  the  tendon,  are  not  regarded 
with  favour. 


Cyclophoria  {Latent  Torsion). — This  consists  in  a  tendency  to  abnormal 
rotation  round  the  antero-posterior  axis  of  the  eyeball,  so  that  the  vertical 
meridians  of  the  eyes  are  no  longer  parallel.  The  subject  is  not,  as  yet, 
well  understood.  A  certain  amount  of  torsion  appears  to  occur  physio- 
logically in  near  vision.  Latent  torsion  can  be  detected  with  the  double 
prism,  a  horizontal  line  being  vised  as  the  test  object.  If  it  be  present,  the 
line  seen  by  the  naked  eye,  between  the  double  image,  will  not  be  parallel 
to  the  double  lines  seen  by  the  eye  clad  with 
the  prism.  Fig.  224  indicates  an  inclination  of 
the  upper  ends  of  the  vertical  meridians 
towards  one  another.  The  opposite  is,  how- 
ever, the  more  common  condition.  Maddox's 
rod  and  Stevens'  clinoscope  are  also  used  for  Fig,   224. 

testing  cyclophoria. 

Maddox's  wing  test  (Fig.  223)  provides  a  very  simple  means  of  detecting 
and  measuring  cyclophoria.  The  wings  are  arranged  as  when  testing  for 
vertical  deviations,  but  the  test  object  consists  of  a  card  with  a  printed 
line  seen  only  by  one  eye  and  an  elastic  movable  thread,  parallel  to  the 
printed  one,  seen  only  by  the  other  eye  ;  if  the  lines  do  not  appear  to  the 
patient  to  be  parallel,  he  is  required  to  move  the  upper  end  of  the  elastic 
thread  until  it  appears  to  be  parallel  to  the  fixed  line,  and  the  degree  of 
inclination  of  the  thread  can  be  read  off  on  a  millimetre  scale  at  the  edge 
of  the  card.  The  deviation  of  the  eye  is  in  the  same  direction  as  the 
inclination  of  the  thread. 

According  to  Savage,  in  astigmatism  witli  i:>bliqvie  axes,  torsion  is 
necessary  to  make  the  vertical  meridians  coincide  with  the  nearest  meridian 
of  the  astigmatism  ;  and  he  believ^es  that  this  accounts  for  the  fact,  that 
some  astigmatic  people  are  more  comfortable  without  correction  of  their 
astigmatism,  being  unable  to  abandon  the  torsion  to  which  they  had 
become  habituated. 


534  DISEASES    OF    THE   EYE.  [chap.   xvii. 


Insufficiency  of  Convergence. — This  has  to  a  great  extent  been  con- 
fused with  exophoria  (latent  divergence)  for  near  vision  ;  indeed,  von 
Grsefe's  test  is  really  one  for  exophoria  or  esophoria  existing  in  near 
vision,  rather  than  for  insufhciency  of  convergence.  The  two  con- 
ditions may  co-exist,  but  one  does  not  involve  the  other.  Either 
may  be  present  alone  ;  furthermore,  a  latent  convergence  (esophoria) 
may  in  some  cases  exist  along  with  insufficiency  of  convergence. 
The  essential  point  in  the  diagnosis  of  the  latter  condition  is  the 
presence  of  a  diminution  of  the  amplitude  of 'convergence  (p.  9) 
as  measured  by  gradually  approaching  to  the  eyes,  in  the  median 
line,  a  series  of  parallel  fine  lines,  or  an  illuminated  line  or  point, 
until  one  eye  is  seen  to  diverge,  or  until  the  patient  gets  crossed 
diplopia.  The  test  should  be  made  on  several  different  occasions, 
as  results  are  liable  to  vary  with  the  state  of  health  or  available 
energy  of  the  patient. 

Causes. — Insufficiency  of  convergence  usually  depends  on  de- 
fective innervation,  due  to  a  central  cause,  which  may  be  organic, 
as  in  locomotor  ataxy,  or  more  commonly  functional,  as  in  hysteria, 
neurasthenia,  anaemia,  and  exophthalmic  goitre  (partly).  Other 
causes  are  myopia  (see  Divergent  Strabismus,  p.  525),  and  perhaps 
sometimes  anatomical  defects  in  the  internal  recti. 

Symptoms. — Patients  complain  of  pains  in  the  head  and  _eyes, 
and  fatigue  after  reading,  sewing,  etc.,  for  any  length  of  time  ;  they 
are  inclined  to  hold  the  book  or  work  farther  from  them,  and  they 
sometimes  get  relief  by  closing  one  eye. 

Treatment. — In  neuropathic  and  debilitated  patients,  the  general 
health  requires  attention  both  mentally  and  physically,  and  out-of- 
door  exercise,  with  peace  of  mind,  should  be  recommended.  With 
regard  to  local  treatment,  exercises  in  convergence,  with  or  without 
the  aid  of  the  stereoscope,  should  first  be  tried,  any  error  of  refrac- 
tion being  of  course  corrected.  A  full  correction  of  myopia,  and 
an  under-correction  of  hypermetropia  may  render  assistance,  by 
making  demands  on  the  accommodation,  and  thus  indirectly  on 
the  convergence.  If  exercises  prove  useless,  prisms  with  bases 
inwards  may  give  relief,  or,  if  glasses  be  worn,  they  can  be  decentred 
(p.  412). 

Should  these  methods  prove  unsuccessful,  advancement  of  one 
internal  rectus,  or  of  both  if  necessary,  should  be  performed. 

Spasm  of  the  orbital  muscles  only  occurs  in  convulsions,  in  con- 


CHAP.    XVII.] 


THE   ORBITAL    MUSCLES. 


535 


jugate  deviations,  and  in  hysteria.  In  the  latter  condition  it  is  not 
uncommon  to  find  spasm  of  the  orbicularis,  witli  convergent  strabis- 
mus and  contraction  of  tlie  pupil  due  to  spasm  of  accommodation. 

Two   very   simple   and   useful   instruments  which   have   of   late   been 
applied  to  the  observation  of  phenomena  connected  with  binocular  vision, 


___-,-0  R 


■^L 


Fia.   225. — To  illustrate  the  principle  of  the  Diploscope. 

including  the  detection  of  malingerers,  are  the  Diploscope  of  Remy,  and 
Harman's  Diaphragm  Test.  These  tests  have  the  advantage  over  the 
stereoscope  of  being  made  under  more  natural  conditions.  We  have  found 
the  instruments  of  great  service  in  ascertaining  the  binocular  effect  of 
the  reading-glasses  ordered  for  presbyopia,  etc. 

The  Diploscope  consists  of  a  screen  with  perforations  through  which 
test  letters  are  seen.  The  holes  may  vary  in  number  and  position.  In  the 
simplest  form  of  the  test  there  are  two  holes  placed  horizontally  through 
which   a   horizontal   row    of    three   or   four    letters   is   visible.       Fig.    225 


D 


I 

1 


_-..0  R 


'-0  L 

Fig.   22(5. — To  illustrate  the  principle  of  the  Diaphragm  Test. 

explains  the  principle  involved.  The  letters  on  the  test  card  T  are  seen 
through  the  two  apertures  in  the  screen  D  in  such  a  way  that  the  consonants 
only  are  visible  to  tlie  right  eye  R,  and  the  vowels  to  the  left  eye  L.  In 
normal  vision  the  letters  appear  in  their  proper  j^osition  as  K  O  L  A  ; 
but  if  the  eyes  diverge,  the  resulting  crossed  diplopia  will  cause  K  L  and 
O  A  to  move  away  from  each  other  so  that  the  test  will  now  read  K  L  O  A. 
Excess  of    convergence  on  the  other  hand  ^\•ill  make  the  pairs  of  letters 


536  DISEASES    OF    THE   EYE.  [chap.  xvii. 

approach  each  other  so  as  to  read  O  K  A  L,  or  in  higher  degrees  O  A  K  L. 
If  there  be  a  vertical  deviation  of  one  eye,  one  pair  of  letters  will  appear 
to  be  higher  than  the  other. 

In  Harman's  test,  Fig.  226,  the  Screen  D  has  only  one  aperture, 
through  which  the  central  portion  of  the  test  on  the  card  T  will  be  visible 
to  both  eyes,  and  the  other  portions  to  one  ej^e  only  ;  for  instance,  No.  3 
is  seen  by  both  eyes,  1  and  2  by  the  right  eye  (R)  only,  and  4  and  5  by  the 
left  eye  (L)  only.  It  is  found  tliat,  in  order  to  obtain  binocular  vision, 
some  persons  require  a  larger  area  visible  to  both  ej^es  than  do  others. 
According  to  Harman,  the  wddth  of  this  area  measures  the  intensity  of 
the  desire  for  binocular  vision,  and  he  has  called  it  the  '  ocular  poise.' 
The  size  of  the  area  common  to  both  eyes  depends  on  the  width  of  the 
aperture,  and  in  the  newer  model  of  the  instrument  this  can  be  varied, 
and  its  measurement  can  be  read  off  on  a  scale. 


Nystagmus. 

By  the  term  nystagmus  (vuo-ray/xdj-,  nodding  of  the  head)  is 
meant  an  oscillation,  or  short  to  and  fro  movement,  of  the  eyes, 
which,  except  in  rare  cases,  is  involuntary.  The  oscillations  may  be 
horizontal  (the  most  common  form),  vertical,  rotatory,  or,  if  mixed, 
may  be  circumductory.  The  movements  of  the  eyes  are  almost 
always  concomitant,  and  usually  constant,  but  they  may  increase 
or  become  visible  in  certain  positions  of  the  eyes  and  diminish 
or  cease  in  others.  They  are  sometimes  accompanied  by  oscil- 
lations of  the  head.  Nystagmus  usually  affects  both  eyes,  but  in 
rare  cases  it  may  be  unilateral.  The  oscillation  disappears  during 
sleep.  There  are  two  essentially  different  types  of  nystagmus  : — 
The  TJndulatory  form  in  which  the  movements  are  equal  in  velocity 
and  range  on  each  side  of  an  imaginary  point,  and  the  Rhythmic, 
jerky,  or  spring-like  form,  in  which  a  relatively  slow  movement  in 
one  direction  is  followed  by  a  more  rapid  movement  in  the  opposite 
direction.  Although  the  slow  component  is  the  primary  one,  the 
direction  of  the  nystagmus  is  named  according  to  the  rapid  phase 
which  is  more  readily  noticed.  A  very  good  example  of  this  form 
of  nystagmus  occurs  under  physiological  conditions,  in  the  case  of  a 
person  watching  objects  from  the  window  of  a  railway  carriage 
in  rapid  motion,  where  the  slower  movement  of  the  eyes  follows 
the  passing  object,  while  the  quick  return  is  in  the  direction  in 
which  the  train  is  travelling. 

Nystagmus,  whether  it  be  congenital  or  acquired,  is  not  a  primary 
affection,  but  is  rather  a»  indication  of  disease  in  the  eye  itself. 


CHAP.  XVII.]  THE    ORBITAL   MUSCLES.  537 

in  the  vestibular  apparatus,  or  in  the  central  nervous  system. 
According  to  some,  undulatory  nystagmus  is  more  liable  to  be 
associated  with  purely  ocular  defects.  But  there  is  no  doubt 
that  the  nystagmus  which  owes  its  origin  to  vestibular  or  nervous 
diseases  is  of  the  rhythmic  type.  Patients  in  whom  nystagmus  is 
due  to  a  congenital  defect  of  vision,  or  whose  sight  becomes  affected 
in  early  life,  do  not  complain  of  anyfapparent  movement  of  visual 
objects  ;  but  those  who  become  affected  with  it  in  later  life  {e.g. 
coal-miners)  are  much  troubled  by  that  symptom,  especially  at  the 
onset. 

1.  Amblyopic  or  Ocular  Ni/staytnus. — When  a  child  is  born  ^Aitli 
defective  vision,  or  when  the  defect  occurs  within  the  first  few  years 
of  life,  the  cerebral  control  over  the  co-ordinating  centres  for  eye- 
movements,  which  depends  on  accurate  fixation  by  the  macula 
lutea,  is  in  abeyance  ;  the  co-ordinating  centres  are  then  thrown 
out  of  gear  by  numerous  other  reflexes  and  the  regular  tonic  con- 
tractions of  the  ocular  muscles  are  replaced  by  irregular  involuntary 
clonic  contractions  (incomplete  tetanus). 

Amongst  the  ocular  diseases  and  defects,  congenital  and  acquired, 
which  cause  nystagmus  may  be  mentioned  opacities  of  the  lens 
and  cornea  (leucomata  following  ophthalmia  neonatorum  is  one  of 
the  commonest  causes),  congenital  colobomata,  astigmatism  with 
amblyopia,  albinism,  chorioido -retinal  and  macular  diseases,  retinitis 
pigmentosa,  and  total  colour  blindness.  Nystagmus  associated  with 
albinism  and  opacities  of  the  media  is  increased  by  exposure  to 
strong  light,  while  in  retinal  affections  the  oscillations  are  greater 
in  the  dark.  Conjugate  deviations  are  often  present  in  congenital 
nystagmus. 

2.  Coal-Miners''  Nystagmus. — This  is  a  form  of  nystagmus  which 
affects  coal-getters,  more  especially  those  who  have  worked  in  the 
mines  for  a  number  of  years.  It  is  believed  by  most  to  be  due  to  the 
long-continued,  imperfect  fixation  caused  by  defective  illumination, 
and  is  undoubtedly  more  common  in  mines  where  protected  lights 
are  used,  than  in  those  in  which  naked  lights  are  employed  and  the 
light  therefore  is  better.  The  oscillations  of  the  eyes  are  rarely 
unilateral :  they  are  purely  undulatory,  most  frequently  rotatory, 
and  are  increased  or  brought  on  by  looking  up,  while  they  diminish 
or  cease  on  looking  down.  The  patients  are  conscious  of  an  apparent 
movement  of  the  visual  fields,  which  causes  headache  and  giddiness. 


538  DISEASES    OF    THE   EYE.  [chap.  xvii. 

Tremor  of  the  head  and  eyelids  with  blepharospasm,  intolerance 
of  light,  and  mental  depression  are  often  present.  Strain  of  the 
ocular  muscles,  nervous  exhaustion,  heterophoria,  and  errors  of 
refraction  have  also  been  advanced  as  possible  associated  causes  of 
miner's  nystagmus. 

3.  Vestibular  Nystagmus. — The  semicircular  canals  and  vestibule 
constitute  one  of  the  chief  peripheral  sources  from  which  reflex  impres- 
sions act  on  the  co-ordinating  centres  in  the  pons  and  thereby  affect  the 
inuscular  tonus  of  the  opposite  side  of  the  body,  including  the  muscles 
concerned  in  associated  movements  of  the  eyes.  The  movement  of  the 
endolymph,  caused  under  normal  conditions  by  alterations  in  the  position 
of  the  head,  provides  the  stimuli  which  gives  rise  to  these  reflexes.  In  the 
case  of  the  horizontal  canals  the  stimulus  is  greater  when  the  movement 
of  the  endolymph  is  from  the  canal  towards  the  ampulla  than  when 
it  is  ampullofugal,  while  in  the  vertical  canals  the  effect  is  the  reverse. 
The  eyes  move  in  the  plane  of  the  affected  canal  and  in  the  same  direction 
as  the  lymph  movement.  In  the  case  of  the  external  or  horizontal  canals 
therefore  the  eyes  will  move  laterally — in  other  words,  there  will  be  a 
conjugate  deviation  to  the  side  opposite  to  the  stimulated  labyrinth.  The 
cerebral  control  over  the  co-ordinating  centres  then  tends  to  correct  this 
deviation  by  a  quicker  movement  in  the  opposite  direction,  thus  causing 
a  rhythmic  nystagmus  which,  since  the  direction  of  the  nystagmus  is 
named  according  to  the  rapid  phase,  will  be  to  the  same  side  as  the 
labyrinth  stimulated.  The  slow  phase  is  the  primary  and  direct  result 
of  the  vestibular  stimulus,  and  this  is  proved  by  the  facts,  amongst  others, 
that  stimulation  of  the  vestibule  in  an  unconscious  person  gives^  rise 
to  the  slow  movement  only,  and  that  the  nystagmus  diminishes  on  looking 
towards  the  side  of  the  slow  component. 

Vestibular  nystagmus  may  be  induced  for  experimental  or  diagnostic  pur- 
poses, or  it  may  arise  spontaneously  iroin  disease  of  the  vestibular  apparatus 
or  of  its  connections. 

Nystagmus  can  be  induced  by  rotation  of  the  patient,  by  syringing 
the  ear  with  hot  or  cold  water  (caloric  test),  by  galvanic  stimulation,  or 
by  pressure  in  cases  of  fistula  of  the  vestibule.  It  will  suffice  in  a  work 
such  as  this  to  give  a  simple  example.  In  the  rotation  test  the  particu.lar 
canal  affected  will  depend  on  the  position  of  the  patient. 

If  the  patient  be  seated  M'ith  head  erect  or  rather  tilted  at  an  angle  of 
30°  forward,  the  horizontal  semicircvilar  canals  will  alone  be  affected  by 
horizontal  rotation  of  the  body.  Fig.  227  explains  the  course  of  events 
when  the  patient  is  rotated  say  from  right  to  left,  as  indicated  by  arrow  1 . 
Diiring  the  rotation  the  endolymph  in  the  canals,  owing  to  inertia,  tends  to 
flow  in  the  direction  of  the  arrows  2  and  2',  i.e.  towards  the  ampulla  in 
the  left  labyrinth  (+),  wliich  becomes  thereby  stimulated  in  excess  and 
cuses  a  slow  movement  of  the  eyes  to  the  opposite  side  in  the  direction  of 
arrow  3.  The  quick  phase  or  nystagmus  will  therefore  be  in  the  direction 
of  arrow  4 — that  is,  in  the  same  direction  as  the  rotation.  On  the  other 
hand,  when  the  rotation  is  stopped  the  lymph  current  will  be  reversed 


CHAP.    XVII. 


THE   ORBITAL   MUSCLES. 


539 


and  the  post-nystagmus,  as  it  is  called,  which  is  easier  to  observe,  will 
now  be  in  the  opposite  direction  to  that  in  which  the  patient  was  rotated. 
This  test  is  used  to  compare  tlie  conditions  of  the  two  labyrinths.  The 
caloric  test,  however,  is  more  easily  applied,  and  has  the  advantage  of 
confining  the  stimulus  to  one  labyrinth  ;  it  is  carried  out  by  syringing 
the  ear  with  warm  or  cold  water.  In  this  test  the  canal  under  investigation 
must  be  vertical.  Syringing  with  hot  water,  except  the  patient  be  in- 
verted, has  the  same  effect  as  increased  stimulation  and  produces  nystag- 
mus to  the  same  side,  whereas  with  cold  water  the  nystagmus  is  contra- 
lateral. 

Froni 


Left 


Right 


Back 

Fig.  227. — Illustrates  Nystagmus  on  Rotation  of  the  Body  to  the  left. 
The  letters  A  A  are  opposite  the  ampullae  of  the  right  and  left  hori- 
zontal canals. 

The  arrows  indicate  : — 1.  Direction  of  rotation  of  patient. 

2.  ,,  ,,     endo lymph  current. 

3.  ,,         ,,     the  slow  ocular  movements. 
The  wavy  arrow  4,  and  the  eyes  above  it,  show  the  direction  of  the  rapid 
phase  (nystagmus)  of  the  eye  movements. 

In  this  case  the  left  labyrinth  marked  +  is  subjected  to  the  stronger 
stimulus. 

Stimulation  of  the  vertical  canals  is  followed  by  a  rotatory  nystagmus, 
which  is  not  uncommonly  accompanied  by  navisea  and  vomiting.  In 
vestibular  nystagmus  an  apparent  movement  of  the  visual  fields  is  seen 
during  the  slow  phases. 

Spontaneous  nystagmus  may  be  caused  by  disease  of  the  vestibular 
apparatus,  either  peripheral  (vestibule,  or  vestibular  nerve)  or  central 
(vestibular  nuclei,  centre  of  co-ordination,  posterior  longitudinal  bands, 
or  fibres  of  connection  with  cerebral  cortex).  In  disease  of  tlie  labyrinth 
itself  the  symptoms,  as  a  rule,  are  the  same  as  those  whicli  follow  a 
destructive  lesion,  and  the  nystagmus,  which  is  of  a  mixed  character, 
is  towards  the  sound  side. 


4.  Nystagmus  in  Diseases  of  the  Nervous  Sijstein. — The  nystagmus 
wliicli  occurs  in  disease  of  the  nervous  system  is  mostly  vestibular 


540  DISEASES    OF    THE   EYE.  [chap.  xvii. 

in  character  and  is  probably  in  most  cases  due  to  involvement  of 
the  vestibular  nuclei,  cerebellum,  or  fibres  of  association.  The 
cerebellum  acts  as  a  regulator  of  reflex  impressions,  and  sends  corre- 
sponding impulses  to  the  oculo -motor  centres  and  to  the  muscles 
concerned  in  maintaining  equilibrium,  and  interference  with  its 
functions  thus  indirectly  causes  nystagmus.  Cerebellar  tumours 
or  abscesses  often  give  rise  to  a  coarse  nystagmus  towards  the  side 
of  the  lesion  and  a  fine  quick  nystagmus  to  the  opposite  side. 
Nystagmus  is  especially  liable  to  occur  in  lesions  situated  towards 
the  dorsal  portion  of  the  pons  and  medulla  extending  from  the 
level  of  the  vestibular  nuclei  below  to  the  corpora  quadrigemina 
above,  and  in  cases  accompanied  by  subtentorial  increase  of  pressure. 

In  Disseminated  Sclerosis  the  nystagmus  is  nearly  always  hori- 
zontal, and  may  only  be  detected  in  extreme  lateral  movements  of 
the  eyes  in  the  early  stage.  In  such  a  case  it  may  be  difficult  to 
distinguish  a  true  nystagmus  from  the  nystagmoid  movements 
which  are  sometimes  seen  in  these  positions  in  normal  individuals, 
or  which  are  met  with  in  cases  of  paresis  of  the  ocular  muscles. 
Indeed  some  authors  regard  this  form  of  slight  nystagmus  in  dis- 
seminated sclerosis  as  an  indication  of  slight  conjugate  paralysis. 

Other  diseases  in  which  nystagmus  is  a  symptom  are  :  Fried- 
rich's  disease,  Heredo-cerebeJlar  Ataxy,  Syringomyelia,  Ataxic  Para- 
plegia, severe  Multiple  Neuritis,  Hysteria,  and  intracranial  injuiies. 

5.  Rare  Varieties  of  Nystagmus  are  Voluntary  Nystagmus,  Here- 
ditary N.,  Spasmus  Nutans,  Myoclonic  N.,  and  Latent  N.  which 
appears  only  on  suppression  of  binocular  vision  by  excluding  one 
eye. 

Treatment. — Congenital  nystagmus  is,  as  a  rule,  incurable,  but 
in  cases  which  admit  of  improvement  of  vision,  a  cure,  partial  or 
complete,  is  sometimes  brought  about  when  the  vision  improves. 
If  stiabismus  be  present,  it  should  be  cured,  after  which  a  diminu- 
tion in  the  oscillations  may  result.  In  miner's  nystagmus,  the  all- 
important  measure  is  a  permanent  relinquishment  of  mine  work  ; 
and  this  is  frequently  followed  by  satisfactory  results. 


CHAPTER    XVIII 

DISEASES   OF   THE   EYELIDS 

Erythema,  erysipelas,  phlegmonous  inflammation,  and  abscess  are 
all  liable  to  attack  the  eyelids,  but  require  no  special  observations 
in  this  work.  It  should  merely  be  stated  that  erysipelas  of  the  eye- 
lids may  extend  to  the  connective  tissue  of  the  orbit  and  ultimately 
give  rise  to  atrophy  of  the  optic  nerve. 

Eczema. — This  is  often  seen  on  the  skin  of  the  eyelids,  most 
frequently  in  connection  either  with  general  eczema  of  the  face  or 
with  phlyctenular  ophthalmia.  The  lacrimation  in  phlyctenular 
ophthalmia  increases  the  eczema,  which  then,  by  causing  contrac- 
tion of  the  skin  of  the  lower  lid,  often  produces  eversion  of  the 
inferior  punctum  lacrimale,  and  this,  in  turn,  causes  increased  lacri- 
mation. 

Atropine  infiltration  of  the  eyelid,  from  use  of  atropine  eye-drops 
in  some  persons,  is  frequently  accompanied  by  a  moist  form  of 
eczema  of  the  lids  and  face. 

Treatment. — Should  the  use  of  atropine  be  the  cause  it  is, neces- 
sary to  discontinue  it,  and  to  substitute  solution  of  Scopolamine 
(gr.  j  and  3]).  As  an  opplication  to  the  affected  skin  the  following 
ointment  is  useful : — Oil  of  Cade,  Viy  iv,  Zinci  oxidi,  gr.  v.  Adipis 
lanse  hyd.  vaselin  alb.,  aa.  51J. 

(Edema  of  the  eyelids  may  be  due  to  general  causes  such  as 
nephritis  or  cardiac  disease,  when  it  is  usually  bilateral  and  non- 
inflammatory. It  is  more  common,  however,  to  find  the  oedema 
on  one  side  only,  and  in  such  cases  it  is  attended  with  more  or  less 
hypersemia  of  the  skin  of  the  eyelids,  and  is  the  result  of  a  local 
inflammation  in  the  eyelids  themselves  (hordeolum,  abscess,  chancre) 
or  of  septic  inflammation  in  the  eye,  lacrimal  sac,  orbit  or  nasal 
sinuses.  In  Thrombosis  of  the  Cavernous  Sinus  the  oedema  is  often 
bilateral  and  exophthalmos  is  present  as  well.  When  an  inflammatory 
oedema  is  limited  to  one  eyelid,  it  is  generally  the  upper  lid  which 

541 


542  DISEASES    OF    THE   EYE.  [ckav.   xvttt. 

is  the  affected  one.  Marginal  oedema  of  the  upper  lid  is  a  frequent 
occurrence  in  septic  iritis,  whether  it  be  metastatic  or  follow  an  injury 
or  operation.  In  old  people  even  after  a  cataract  operation  which 
progresses  normally,  the  mere  pressure  of  the  bandage  may  cause  an 
oedema  of  the  upper  lid,  which  is  usually  most  marked  above  the 
inner  canthus.  Again  oedema  of  the  upper  lid  may  be  the  first 
sign  of  disease  of  the  frontal  sinus,  and  hordeola  are  particularly 
liable  to  cause  oedema  if  they  be  situated  at  the  inner  or  outer  canthus. 
Amongst  other  causes  may  be  mentioned  stings  or  bites  of  insects 
and  foreign  bodies  under  the  upper  lid,  and  it  should  not  be  forgotten 
that  Iodide  of  Potassium  may  produce  it. 

Angio-neurotic  oedema  of  the  eyelids  is  a  peculiar  non-inflamma- 
tory form  of  transient  and  recurring  oedema,  met  with  chiefly  in 


Fig.  228. 

young  females  who  sometimes  develop  oedema  of  a  similar  kind  in 
other  parts  of  the  body.  CEdematous  eyelids  pit  on  pressure  and 
can  easily  be  distinguished  from  the  swollen  lids  in  myxoedema, 
solid  oedema  (Fig.  228),  and  ptosis  adiposa.  In  emphyssema,  too, 
the  peculiar  sensation  communicated  to  the  fingers  on  palpation 
will  prevent  its  being  mistaken  for  oedema. 

The  condition  known  as  Solid  CEdema,  Elephantiasis  Lymphan- 
gioides,  or  Elephantiasis  Nostras  of  the  Eyelids,  is  well  represented  in  the 
accompanying  picture  (Fig.  228)  of  a  case  under  the  care  of  Sir  A.  Critchett. 
It  is  a  chronic  tumefaction  of  the  eyelids.  The  skin  covering  the  swelling 
is  smooth  and  pale,  and  resembles  the  skin  of  an  oedematous  lid  ;  but  on 


CHAP.   xvTTT.]  THE    EYELrnS.  r>43 


palpation  the  swelling  is  found  to  be  more  resistant  than  simple  csdema. 
There  is,  almost  invariably,  a  liistory  of  recurring  attacks  of  facial  erysipelas. 
These  give  rise  to  a  permanent  alteration  of  the  lymph  channels,  and, 
each  attack  leaving  its  trace,  an  ever-increasing  hypertrophy  of  the 
tissues  of  the  eyelids  takes  place. 

Treatment. — Operative  measures  have  been  adopted  in  many  instances 
with  satisfactory  results,  both  cosmetically  and  as  regards  the  functions 
of  the  eyelids  ;  but,  imfortunately,  in  those  cases  which  have  remained 
under  observation  sufficiently  long,  the  former  condition  gradually 
returned,  as  in  Sir  A.  Critchett's  case  (Fig.  228),  in  tlio  picture  of  whicli 
the  cicatrices  of  the  operations  can  be  seen.  Multiple  punctures,  collodion, 
pressure,  etc.,  and  many  internal  remedies  have  been  tried  in  vain. 
Drainage  by  the  insertion  of  subcutaneous  threads  after  tlie  method  of 
Hanley  has  proved  of  service,  and  is  worthy  of  trial. 

Marginal  Blepharitis  {(SXecfiapov,  eyelid),  or  Ophthalmia  Tarsi, 
is  nothing  else  than  eczema  of  the  margin  of  the  eyelid.  It  is  found 
either  as  Blepharitis  Ulcerosa  (Eczema  Pustulosa),  or  as  Blepharitis 

Squamosa  (Eczema  Squamosa).  In  blepharitis  ulcerosa,  small 
pustules  form  at  the  roots  of  the  eye  lashes,  and  these,  having  lost 
their  covering,  become  ulcers,  which  scab  over.  The  \vhole  margin 
of  the  licl  may  then  be  covered  with  one  large  scab,  in  which  the 
eyelashes  are  matted,  and  under  which  the  lid  will  be  found  swollen, 
red,  and  moist,  with  many  minute  ulcers  and  pustules,  the  latter 
due  to  suppuration  of  the  hair  follicles  and  of  the  sebaceous  glands 
belonging  to  them.  Many  eyelashes  come  away  with  the  scab 
when  removed,  and  others  are  found  loose  and  ready  to  fall  out. 
Cicatrices  resulting  from  the  suppuration  are  also  present,  and  there 
the  hair  follicles  are  destroyed,  and  the  cilia  do  not  grow  again. 

The  disease  is  chronic,  and  is  most  commonly  seen  in  strumous 
children.  It  is  frequently  accompanied  by  phlyctenular  ophthalmia, 
or  by  simple  conjunctivitis,  which  may  have  been  its  cause,  or  which 
promotes  it  by  keeping  the  margin  of  the  lid  constantly  wet. 

Blepharitis  is  sometimes  associated  with  lacrimal  obstruction 
and  the  cliplobacillus  is  responsible  for  the  disease  in  some  cases, 
more  especially  in  angular  blepharitis. 

If  neglected,  ulcerous  Ijlepharitis,  by  reason  of  the  scars  it  pro- 
duces, is  liable  to  give  rise  not  only  to  peimanent  loss  of  eyelashes, 
but  to  irregular  growth  (trichiasis)  of  those  which  remain.  After 
a  time,  the  continued  congestion  and  inflammatory  swelling  of  the 
lid  margin  leads  to  its  hypertrophy,  chiefly  of  the  upper  lid. 

The  margin  of  the  lower  lid  is  liable  to  become  everted,  owing 


■)44  DISEASES    OF    THE    EYE.  [chap,   xvitt. 

to  contraction  of  the  skin  of  the  evelicl.  Involved  in  this  eversion 
is  the  lower  punctum  lacrimale,  and  consequently  lacrimation 
ensues,  with  resulting-  eczema  of  the  eyelid,  which  in  turn  promotes 
the  ectropion,  while  the  exposure  of  the  conjunctiva  of  the  lower 
lid  increases  the  already  existing  conjunctivitis. 

The  Treatment  of  Ulcerous  Blepharitis  consists,  in  the  first  place, 
in  the  careful  removal  of  the  scahs.  without  causing  any  bleeding 
of  the  delicate  surface  underneath.  Bleeding  indicates  that  newly 
formed  epithelium  has  been  torn  away,  and  it  is  important,  there- 
fore, to  soften  the  scabs  by  soaking  the  eyelid  with  olive  oil,  or  with 
a  warm  saturated  solution  of  bicarbonate  of  soda,  before  removing 
them.  Any  pustules  found  under  the  scab  should  be  punctured, 
and  all  loose  eyelashes,  which  act  as  foreign  bodies,  taken  away. 
Also  all  diseased  eyelashes  should  be  drawn  away.  These  are 
recognised  by  aid  of  a  magnifying  glass  as  shorter,  thicker,  straighter. 
and  more  highly  pigmented  than  the  normal  ciliae  ;  and  when  re- 
moved their  roots  are  found  to  be  club-shaped.  The  ulcers  should 
be  carefully  touched  twice  a  week  with  a  fine  point  of  solid  mitigated 
lapis.  The  surface  should  then  be  well  dried  by  pressure,  not  by 
rubbing,  with  cotton  wool,  and  the  following  ointment  rubbed  in 
with  a  glass  rod — Hydrarg.  pracip.  alb.  gr.  vj,  Zinci  oxidi  gr.  viij, 
Liq.  plumbi  subacet.  n\  vj,  Adipis  benzoat.  ad.  3iv.  This  ointment 
is  to  be  continued  by  the  patient,  night  and  morning,  after  the  lids 
have  been  w^ashed,  and  all  scabs  and  loose  eyelashes  removed 
from  them,  and  well  dried,  until  healing  is  thoroughly  established. 
In  many  mild  cases  a  boric  acid  ointment  (gr.  ij  ad  3j  of  vaseline 
or  of  lanolin)  will  be  found  efficacious  instead  of  the  above.  A 
creolin  ointment  suits  many  cases,  if  it  do  not  irritate — viz.  Creolin, 
1  to  5  min.  ;    Aq.,  3ij  ;    Lanolin,  5vj. 

Or,  again,  after  the  scabs  and  loose  and  diseased  eyelashes  have 
been  removed  as  above,  the  margins  of  the  eyelids  may  be  freely 
bathed  with  a  wash  of  ten  to  twenty  minims  of  creolin  to  eight 
ounces  of  water,  and  after  this  the  creolin  ointment  may  be  applied. 
A  first  principle  of  treatment  in  all  these  cases  is  that  it  be  non- 
irritating.  If  caused  by  the  diplobacillus  preparations  of  zinc  are 
indicated.  Noviform  in  5  to  20  per  cent,  ointment  has  been  much 
recommended  of  late. 

All  complications  with  conjunctival  affections  or  lacrimal  ob- 
struction must  be  attended  to,  the  patient's  general  system  carefully 


PHAP.  XV 1 1 1.]  THE    EYELIDS. 


improved,  and  oiiors  of  relraetiuii  eoirected.     lu  inveterate  cases, 
the  use  of  staphylococcus  vaccine  is  indicated. 

Squamous  Blepharitis  comes  on  after  the  ulcerous  form  has 
passed  away  ;  or,  it  is  found  as  a  primary  affection,  especially  in 
chlorotic  women.  The  margin  of  the  lid  is  somewhat  swollen  and 
red,  and  covered  with  loose  epidermic  scales.  It  is  an  extremely 
chronic  affection,  but,  although  disfiguring,  it  has  no  dangerous 
sequelye. 

The  Treatment  of  Squamous  Blepharitis.  Boric  acid  ointment 
(gr.  XX  ad.  5j). 

Chlorosis,  if  present,  should  be  treated  with  suitable  remedies. 

Phtheiriasis  {<iiOup,  a  louse)  Ciliorum. — The  pediculus  pubis 
occurs  on  the  eyelashes.  It  gives  rise  to  excessive  itching  and  burn- 
ing sensations,  and  the  consequent  rubbing  produces  excoriations 
of  the  margin  of  the  lid.  The  lice  occupy  chiefly  the  roots  of  the 
eyelashes,  to  which  they  cling  tenaciously,  while  the  shafts  of  the 
cilia  are  covered  with  their  brown  egg-capsules  ;  and  this  gives 
to  the  cilia  the  peculiar  appearance  of  being  covered  with  dark 
brown  powder,  which  enables  the  diagnosis  to  be  easily  made.  The 
fully  developed  parasites,  as  well  as  the  eggs,  may  be  more  readily 
seen  by  aid  of  a  strong  convex  glass. 

Treatmentt. — With  a  cilium  forceps  the  pediculi  as  well  as  some  of 
the  eggs  may  be  removed  from  the  cilia.  This  proceeding  repeated 
daily,  along  with  the  application  of  mercurial  ointment,  or  of  a  weak 
red  precipitate  ointment,  to  the  margin  of  the  eyelids  morning  and 
evening,  will  soon  effect  a  cure. 

Hordeolum  {hordeum,  a  grain  of  barley),  or  Stye,  is  a  circum- 
scribed purulent  inflammation  situated  at  the  fallicle  of  an  eyelash. 
It  commences  as  a  hard  swelling,  with  more  or  less  tumefaction 
and  oedema  of  the  general  surface  of  the  lid,  and  often  with  some 
chemosis,  especially  if  it  be  situated  at  the  outer  canthus.  In  its 
early  stages  there  is  much  pain  associated  with  it.  It  gradually 
suppurates,  and  may  then  be  punctured  or  allowed  to  open  of 
itself. 

Styes  frequently  come  in  rapid  succession,  and  then,  probably 
a  constitutional  disturbance  exists  as  the  cause.  In  the  earliest 
stage  cold  applications  may  be  successful  in  putting  back  a  stye,  but, 
later  on,  warm  stupes  will  hasten  the  suppuration  and  relieve  the 
pain.  Habitual  constipation  is  a  common  source  of  hordeolum, 
35 


540  DISEASES    OF    THE   EYE.  [chap,  xviii. 


and  should  be  met  by  the  use  of  mild  laxatives.  Sulphide  of  cal- 
cium, -^^J  gr.  every  hour,  or  I  gr.  twice  a  day,  for  an  adult,  has  been 
recommended  as  a  specitic  in  these  cases.  If  there  be  troublesome 
recurrences,  staphylococcic  vaccine  treatment  can  be  adopted. 

Chalazion  (xaka^a,  hail),  Meibomian  Cyst,  or  Tarsal  Cyst,  is 
probably  a  granuloma  in  connection  with  a  Meibomian  gland,  and 
not  a  mere  retention  cyst.  The  glanuloma  consists  of  round  and 
epithelioid  cells  and  sometimes  giant  cells.  Chalazion  has  its  origin 
in  a  slight  chronic  inflammatory  process  in  the  connective  tissue 
surrounding  the  gland,  which  usually  passes  off  without  having 
attracted  the  attention  of  the  patient,  but  occasionally,  when  the 
cyst  has  developed,  acute  inflammation  with  formation  of  pus  comes 
on.  The  tumours  vary  in  size  from  that  of  a  hemp-seed  to  that  of 
a  hazel-nut,  causing  a  marked  and  very  hard  swelling  in  the 
lid  without  any  redness  of  the  latter.  They  may  last  for 
several  months.  Occasionally  they  open  spontaneously  on  the 
conjunctival  surface,  giving  exit  to  contents  which  are  usually  viscid 
or  grumous,  and  sometimes  purulent,  and  subsequently  a  reddish 
granulation  forms,  which  becomes  more  or  less  flattened  against  the 
eyeball  by  the  pressure  of  lid. 

Treatment. — No  application  can  bring  about  absorption  of  these 
tumours.  Local  anaesthesia  having  been  produced  by  an  acoine, 
or  by  a  cocaine  and  adrenaline  injection,  the  lid  is  everted,  and  the 
tumour  is  opened  by  an  incision  from  the  conjunctival  surface,  and 
its  contents  thoroughly  evacuated  by  aid  of  a  small  curette.  The 
operation  is  greatly  facilitated  by  the  use  of  a  chalazion  clamp 
forceps,  which  render^;  the  tumour  more  prominent  and  checks 
haemorrhage.  Difficulty  is  sometimes  experienced  in  finding  the 
point  in  the  conjunctiva  corresponding  wdth  the  tumour,  but  it  is 
usually  indicated  by  a  dusky  or  greyish  discoloration.  Immedi- 
ately after  the  evacuation,  bleeding  into  the  sac  often  takes  place, 
and  causes  the  tumour  to  remain  for  a  day  or  two  as  large  as  before 
— a  fact  of  which  the  patient  should  be  warned.  The  operation 
may  occasionally  require  to  be  repeated.  The  interior  of  the  sac 
should  not  be  touched  with  nitrate  of  silver ;  and  the  incision  and 
evacuation  should  not  be  made  through  the  skin,  unless  in  rare 
instances  when  the  capsule  is  exceptionally  thick,  as  more  or  less 
disfigurement  from  the  scar  many  result. 

More  than  one  chalazion  is  often  present  at  a  time,  and  some 


CHAP.    XVIII. 


THE    EYELIDS.  547 


people  become  litibte  to  them  periodically  during  a,  number  of  years, 
especially  those  who  sutler  from  acne  of  the  face. 

'^^  Milium  {miliiun,  a  millet  seed)  presents  the  a2)pej)rancc  of  a 
perfectly  white  tumour,  not  much  larger  than  the  head  of  a  pin, 
in  the  skin  of  the  eyelid.  It  is  a  retention  tumour  of  a  sebaceous 
gland,  and  can  readily  be  removed  1)y  puncture  and  evacuation. 

*  Molluscum,  or  Molluscum  Contagiosum.— This  is  a  white 
tumour  in  the  skin  of  the  eyelid,  which  may  attain  the  size  of  a 
pea.  At  its  summit  is  a  depression,  which  leads  to  an  opening  into 
the  tumour,  through  which  the  contents  can  be  pressed  out.  It  is 
probably  a  diseased  condition  of  a  sebaceous  gland,  and  contains 
altered  epithelial  cells,  and  peculiar  bodies,  termed  molluscum  cor- 
puscles, which  are  of  a  fatty  nature.  Many  such  tumours  may 
form  in  the  lids  at  the  same  time.  It  is  held  by  some  observers 
that  this  affection  is  contagious,  although  in  what  way  is  not  clear, 
inasmuch  as  experimental  rubbing  of  the  contents  of  a  molluscum 
into  the  skin  has  not  given  rise  to  the  tumours. 

Treatment. — Each  separate  tumour  must  be  evacuated  by 
simple  pressure,  or  after  it  has  been  opened  up  with  a  knife  or  scissors. 
Teleangiectic  Tumours,  or  Naevi,  of  the  eyelids  occur  congenitally. 
Treatment. — Small  tumours  of  this  kind  may  be  destroyed  by 
touching  with  nitrate  of  silver  or  hydrochloric  acid,  or  by  performing 
vaccination  on  them  in  the  case  of  infants,  instead  of  on  the  arm. 
Larger  tumours  may  be  ligatured  or  treated  with  the  galvano- 
cautery,  or  with  ethylate  of  soda,  or  carbonic  acid  snow,  and  elec- 
trolysis is  a  very  effectual  method  in  many  cases. 

*  Xanthelasma  (far^o?,  yellow]  (Xaafxn,  a  layer)  is  the  term 
applied  to  yellowish  plaques  raised  slightly  over  the  surface  of  the 
skin  of  the  eyelid,  with  very  defined  margins.  Women  are  more 
liable  to  it  than  men.  The  patches  are  generally  bilateral  and  sym- 
metrical, and  are  most  frequently  situated  in  the  neighbourhood  of 
the  inner  canthus.  The  shape  of  these  plaques  is  extremely  irregular, 
and  they  may  attain  the  size  of  a  shilling  or  larger.  The  appearance 
is  caused  by  changes  in  the  middle  layers  of  the  corium,  consisting 
of  aggregations  of  large  epithelioid  cells,  with  development  of  con- 
nective tissue,  and  of  yellowish  brown  pigment  in  and  about  the 
cells,  with  fatty  degeneration  of  the  connective  tissue. 

Treatment. — Removal  by  careful  dissection  is  sometimes  em- 
ployed, but  can  hardly  be  recommended  unless  under  exceptional 


548  DISEASES   OF    THE   EYE.  [chap,  xviit. 


circumstances  ;  the  giowtli,  moreover,  is  liable  to  recur.  But  good, 
and  apparently  permanent,  cures  have  been  effected  by  means  of 
radium.  Electrolysis  too  can  be  used.  A  platinum  needle  is  passed 
about  5  mm.  under  the  growth  and  parallel  to  the  skin  and  allowed 
to  remain  a  few  seconds,  five  or  six  such  insertions  being  made 
fairly  close  to  each  other.  A  scab  forms  and  comes  away  in  a  few 
days,  and  thus  in  a  few  sittings  the  entire  growth  will  have  been 
attacked.  Care  must  be  taken  to  destroy  the  whole  growth,  or  a 
recurrence  will  take  place. 

Palpebral  Chromidrosis  (xpw/i«,  colour;  'H^poaig,  sweating). — The 
phenomenon  of  an  exudation  of  pigment  upon  the  eyehds,  of  which  a 
good  many  cases  are  recorded,  has  given  rise  to  mu3h  discussion.  The 
opinion  held  by  many  is  that  these  cases  are  always  the  result  either  of  de- 
ception in  hysterical  individuals,  or  of  accidental  circumstances,  such  as  the 
exposure  of  a  patient  with  seborrhcea  palpebrarum  to  an  atmosphere 
loaded  with  coal-dust  or  pigmentary  matter,  in  some  manufacturing 
district.  Of  the  fact  that  the  appearance  has  occurred  under  both  of 
these  conditions  there  can  be  no  doubt.  There  would  seem  also  to  be 
evidence  that  some  genuine  cases  of  colour-sweating  on  the  eyelids  have 
been  observed  ;  but  they  must  be  extremely  rare.  The  discoloration  is 
blue  or  black,  and  occui's  in  the  form  of  fine  powder  upon  the  skin  of 
one  or  both  eyelids  of  both  eyes.  It  can  be  wiped  off,  and  is  said  to 
begin  to  reappear  after  a  short  interval.  The  subjects  of  it  have  been 
chiefly  young  girls,  but  it  has  also  been  seen  in  women  of  advanced  years 
and  even  in  middle-aged  men. 

The  Treatment  in  a  genuine  case  may  consist  in  the  application  of  a 
lotion  of  liq.  plumbi  and  glycerine  ;  and,  internally,  iron,  quinine,  and 
arsenic,  along  with  the  regulation  of  the  general  system,  particularly  in 
respect  of  any  uterine  derangement. 

Herpes  Zoster  Ophthalmicus  is  a  herpetic  eruption  of  the  skin 
in  the  region  supplied  by  the  ophthalmic  division  of  the  fifth  nerve 
of  one  side. 

Occasionally,  in  the  same  case,  the  second  division  of  the  fifth 
nerve  may  be  affected,  and,  yet  more  rarely,  the  third  division  as 
well.  One  or  two  cases,  too,  have  been  published  in  which  the 
zoster  affected  each  side  of  the  face. 

But  by  far  the  most  common  case  is  the  simple  herpes  zoster 
ophthalmicus,  in  which  only  the  region  supplied  by  the  ophthalmic 
division  of  the  fifth  nerve  is  affected  ;  and  of  this  region  it  is  usually 
that  portion  alone  which  pertains  to  the  supra-orbital  and  infra- 
trochlear  branches  that  is  involved,  as  is  represented  in  Fig.  229. 
The  number  of  vesicles  varies  much  ;  there  may  be  but  one,  or  there 
may  be  several,  or  they  may  be  so  numerous  as  to  become  confluent. 


CHAP.    XV  in. 


THE   EYELIDS. 


549 


Fig.   229. 


The  appearance  of  the  eruption  is  often  preceded  by  a  feeling  of 
general  discomfort,  gastric  disturbance,  and  high  temperature.  Yet 
more  commonly  the  eruption  is  preceded  by  supra-orbital  neuralgia, 
which  is  often  severe.  This  pain  usually  continues,  but  may  cease, 
after  the  eruption  comes  out,  and  sometimes  it  persists  even  for 
many  months  after  the  eruption 
disappears.  Photophobia,  due  to 
the  irritation  of  the  fifth  nerve,  is 
not  uncommon  at  the  commence- 
ment of  the  affection.  Along  with 
the  appearance  of  the  herpes  the 
skin  of  the  forehead  becomes  red  and 
swollen,  and  the  appearances  are 
often  mistaken  for  erysipelas,  but  the 
strict  limitation  of  the  eruption  by 
the  vertical  middle  line  of  the  fore- 
head is  of  itself  sufficient  to  indicate 
the  diagnosis.  The  upper  lid  is 
somewhat  oedematous  and  red,  and 

droops  over  the  eye,  and  this  is  much  more  marked  when  the  skin 
of  the  eyelid  itself  is  the  seat  of  vesicles. 

The  contents  of  the  vesicles  soon  become  purulent  and  haemor- 
rhage may  take  place  in  them.  They  then  gradually  dry  up,  and 
form  crusts,  which  conceal  more  or  less  deep  ulcers,  and  as  these 
ulcers  often  penetrate  to  the  corium  they  are  liable  to  leave  per- 
manent scars  behind,  which  at  first  are  red,  and  later  become  cf 
a  glistening  white.  The  entire  eruptive  process  lasts  about  three 
weeks  ;  and,  when  it  is  completed,  the  sensibility  of  the  affected  skin 
remains  dull  for  a  considerable  time.  Herpes  zoster  ophthalmicus 
is  more  common  in  advanced  life  than  in  youth,  but  it  may  appear 
at  any  age,  and  has  been  observed  as  early  as  the  sixth  month  after 
birth. 

The  disease  is  not  associated  with  danger  to  the  eye,  unless 
keratitis  come  on,  or,  what  is  much  more  rare,  unless  iritis,  cyclitis, 
or  chorioiditis  appear.  The  conjunctiva  is  almost  always  slightly 
chemotic  and  injected,  or  there  may  be  true  conjunctivitis ;  but 
vesicles  are  not  often  seen  on  it. 

There  is  considerable  variety  in  the  forms  of  keratitis  liable  to 
occur  in  herpes  zoster  ophthalmicus — viz.  herpetic  vesicles,  phlycte- 


550  DISEASES    OF    THE   EYE.  [chap,  xviii. 

nulsc,  bullae  (any  of  which  may  go  on  to  ulceration),  superficial 
opacity  without  loss  of  substance,  and  parenchymatous  opacity, 
either  diffuse  or  punctate.  The  superficial  opacities  without  loss  of 
substance  may  disappear  completely.  Parenchymatous  opacity 
either  clears  away  completely,  or  remains  as  a  slight  nebula  ;  while 
ulceration  leaves,  at  the  least,  some  opacity ;  or,  if  it  become 
septic,  may  seriously  endanger  the  eye.  Anaesthesia,  more  or  less 
well  marked,  attends  the  corneal  affections,  and  remains  for  a  long 
time  after  they  recover. 

Iritis  is  very  uncommon  in  herpes  zoster  ophthalmicus,  and  is 
usually  cf  a  mild  type,  and  iiido-cyclitis  and  chorioiditis  are  still 
more  uncommon. 

Herpes  zoster  ophthalmicus  is  due  to  an  inflammatory  process 
in  the  Gasserian  ganglion,  as  Head  and  Campbell  have  shown,  and 
in  the  opinion  of  these  authors  the  skin  eruption  is  caused  by  intense 
irritation  of  the  ganglion  cells.  The  lesion  in  the  Gasserian  ganglion 
is  similar  to  that  found  in  the  posterior  root  ganglion  in  zoster  of  the 
trunk  and  limbs.  Head  and  Campbell  believe  the  affection  to  be 
an  acute  specific  disease — a  view  suggested  by  the  facts  that  it 
occurs  in  the  course  of  recognised  infective  diseases,  that  it  occurs 
endemically  and  epidemically,  and  that  it  rarely  occurs  a  second 
time.  It  is  probable  that  the  affection  may  also  have  a  toxic  arigin, 
as  when  arsenic  has  been  taken  for  a  long  time,  and  in  carbonic  oxide 
poisoning. 

Treatment. — It  is  doubtful  whether  treatment  has  any  influence 
in  curing  or  in  controlling  the  severity  of  an  attack  of  herpes  zoster 
ophthalmicus.  Quinine  in  full  doses  should  be  given,  and  a  1  per 
cent,  cocaine  ointment  made  with  equal  parts  of  vaseline  and  lanolin 
should  be  smeared  lightly  over  the  affected  part.  Complications  in 
the  cornea  or  uveal  tract  are  to  be  dealt  with  on  the  principles  laid 
down  in  the  chapters  on  diseases  of  those  organs.  The  patient,  unless 
the  attack  be  a  very  mild  one,  should  be  confined  to  bed. 

Syphilitic  Affections  of  the  Eyelids. — Primary  Syphilitic  Sores  occur 
on  the  eyelids,  usually  near  the  margm  of  the  upper  or  lower  lid,  or  at  the 
inner  or  outer  canthus,  or  may  occupy  the  conjunctival  surface  of  the 
eyelid.  The  first  a^^pearance  is  generally  a  small  red  swelling  which  the 
patient  calls  a  '  pimple,'  and  which  ulcerates  and  becomes  characteristically 
indurated  about  its  base.  The  margin  of  the  ulcer  is  clean-cut,  and  its 
floor  somewhat  exca\'Tited,  and  covered  with  a  scanty  greyish  secretion. 
Or,  without  any  ulceration,  the  lid  is  swollen,  greatly  indurated,  purple, 


(HAr.   will.]  THE   EYELIDS.  551 


and  sliiny  ;  and  in  these  cases  the  diagnosis  may  he  somewhat  diflicult. 
The  pre-auricular  and  sub-maxillary  glands  are  almost  always  swollen  ; 
and  this  is  a  valuable,  although  not  altogether  positive,  diagnostic  sign, 
as  it  is  seen  also  in  tubercular  diseases  of  the  conjunctiva.  Tlie  presence 
of  spirochoetes  in  the  secretion,  or  a  positive  Wassermann  test,  will  deter- 
mine the  diagnosis.  The  occurrence  of  the  sore  is  followed  by  the  usual 
constitutional  symptoms  of  syphilis.  Very  rarely  is  there  any  permanent 
damage  done  to  the  eyelid. 

The  most  common  modes  of  infection  are  by  a  kiss  from  a  syphilitic 
mouth,  or  by  a  finger. 

In  view  of  the  rarity  of  this  affection,  as  also  of  interstitial  keratitis 
in  acquired  syphilis,  quite  a  number  of  cases  have  been  recorded,  in 
which  interstitial  keratitis  followed  in  the  eye  the  lid  of  which  had  pre- 
viously been  the  seat  of  a  primary  syphilitic  sore. 

Treatment. — Locally,  iodoform  ointment,  dusting  with  finely  powdered 
iodide  of  mercury,  or  the  black  wash  may  be  used  ;  wliile  salvarsan,  or 
the  usual  general  mercurial  treatment  is  employed. 

Secondary  Syphilis  gives  rise  to  ulcers  on  the  margins  of  the  lids,  to 
loss  of  the  eyelashes,  and  to  the  secondary  skin  affections  which  attend 
it  in  other  parts  of  the  body. 

In  Tertiary  Syphilis  a  gummatous  infiltration  of  the  tarsus — so-called 
Syphilitic  Tarsitis — may  occur,  but  it  is  a  rare  affection.  One  or  both 
eyelids,  in  one  or  both  eyes,  may  be  attacked.  Without  pain  the  lid 
becomes  slowly  and  gradually  hypertrophied,  and  the  integument  tightly 
stretched  and  hyperaemic.  On  palpation,  which  gives  no  pain,  the  tarsus 
can  be  felt  to  be  enlarged  and  of  cartilaginous  density.  The  i^alpebral 
conjunctiva  is  somewhat  swollen,  but  through  it  the  yellowish-white 
colour  of  the  gummatous  infiltration  can  be  seen,  if  it  be  possible  to  evert 
the  lid.  Ptosis  results,  and  the  lid  may  be  so  hard  and  stiff  as  to  render 
eversion  impossible.  The  eyelashes  fall  out,  and  the  pre-auricular  gland 
is  swollen.  Although,  as  stated,  the  process  is  remarkable  for  its  freedom 
from  pain,  yet  severe  pain  may  be  experienced,  should  a  rapid  increase 
in  the  gummatous  infiltration  take  place.  Under  treatment — which 
consists  of  iodide  of  potash  and  mercury — the  infiltration  disappears, 
and  leaves  a  normal  eyelid  behind,  or  the  tarsus  may  be  somewhat  atrophied 
as  a  result. 

Vaccine  Vesicles  on  the  Eyelids  are  produced  by  accidental  inocula- 
tion at  the  intermarginal  part  of  the  lid  ;  or  on  the  outer  surface  of  the 
lid,  if  the  skin  be  abraded  by  a  finger-nail  or  otherwise.  Sometimes  the 
vesicle  develops  into  a  large  ulcer  with  yellowish  floor  and  hard  and  ele- 
vated margin.  There  is  much  pain,  much  swelling  of  the  eyelid,  and 
chemosis. 

Although  distressing  for  a  week  or  so  while  it  lasts,  the  affection  is 
not  a  dangerous  one,  further  than  that  a  cicatrix  in  the  skin  is  left  behind, 
and  the  eyelashes  at  the  affected  part  are  lost. 

Treatment. — A  warm  chlorate  of  potash  lotion  (gr.  v  ad  5J)  is  the  best 
application. 

Rodent  Urcer  (Jacob's  ITJcer). — This  disease  commences  as  a 


552  DISEASES    OF    THE   EYE.  [chap,  xviii. 

small  pimple  or  wart  on  the  skin  near  the  inner  canthus,  or  over  the 
lacrimal  bone,  as  a  rule  ;  but  it  may  also  originate  in  any  other  part 
of  the  face.  The  scab  or  covering  of  the  wart  is  easily  removed,  and 
underneath  is  found  a  shallow  ulcer  with  a  well-defined,  raised,  and 
indurated  margin,  the  skin  surrounding  the  diseased  area  being 
healthy.  The  progress  of  the  disease  is  extremely  slow,  extending 
over  a  great  number  of  years,  and  in  the  early  stages  the  ulcer  may 
even  seem  to  heal  for  a  time,  but  always  breaks  out  again.  In 
mild  cases  the  ulceration  may  remain  superficial ;  but  more  usually 
it  strikes  deep,  in  the  course  of  time  eating  away  every  tissue,  even 
the  bones  of  the  face  and  the  eyeball.  The  latter  is  often  spared 
until  after  the  orbital  bones  have  gone. 

The  disease  is  an  epithelial  cancer  of  a  non-malignant  or  purely 
local  kind.  There  is  no  tendency  to  infiltration  of  the  lymphatics. 
It  is  rarely  seen  in  persons  under  forty  years  of  age. 

Treatment. — Extirpation  of  the  diseased  part  with  the  knife, 
followed  by  the  application  of  chloride  of  zinc,  or  of  the  actual 
cautery,  used  formerly  to  be  employed;  and  Bergeon's  treatment, 
with  the  internal  administration  of  chlorate  of  potash,  and  its  local 
application  as  a  lotion,  was  also  used  with  benefit  for  the  time. 

The  Rontgen  Ray  treatment  enables  brilliant  cures  to  be  effected 
in  many  of  these  terrible  cases.  Dr.  W.  S.  Haughton,  who  is  in 
charge  of  the  Rontgen  Ray  department  of  the  Victoria  Hospital, 
has  given  us  the  following  description  of  the  method  which  he  finds 
to  be  the  most  successful  in  the  treatment  of  rodent  ulcer  : — When 
the  ulcer  is  large,  lumpy,  or  prominent,  it  is  advisable  to  remove  as 
much  as  possible  of  its  floor  and  margin  by  excision  or  cautery,  so 
as  to  expose  its  growing  base  directly  to  the  Rontgen  Rays.  The 
ulcer  is  exposed  to  the  rays,  at  a  distance  of  not  less  than  six  inches, 
through  an  accurately  shaped  window  in  a  mask  of  led  foil.  A 
layer  of  cotton-wool  or  other  non-conducting  material  is  placed 
between  the  patient's  skin  and  the  lead  foil.  The  affected  part  is 
given  two  minutes'  exposure  to  the  rays  every  second  day,  until 
definite  signs  of  reaction  appear.  For  superficial  ulcers  a  soft 
X  Ray  tube  gives  the  best  results,  when  deep  tissues  are  affected  a 
hard  tube  is  preferable.  From  10  to  20  sittings,  according  to  the 
extent  and  depth  of  the  ulcer,  are  usually  necessary  to  effect  a  cure. 
Early  cases  are  of  course  the  most  favourable  for  treatment,  but  in 
far  advanced  cases — even  when  the  eveball  was  cone,  and  the  bones 


cnAr.   xviii.]  THE    EYELIDS.  553 

of  the  orbit  extensively  destroyed,  with  visible  pulsations  of  the 
brain  through  the  roof  of  the  orbit — the  growth  of  the  disease  has 
been  arrested,  and  all  pain  and  hcTmorrhage  have  been  stopped. 

In  rodent  ulcers  of  small  extent  radium  is  capable  of  effecting 
good  cures.  Two  or  three  5  mg.  tubes  of  first  quality  radium  are 
applied  to  the  ulcerated  surface  for  about  half  an  houi,  at  intervals 
of  ten  days  to  three  weeks,  and  to  a  different  part  of  the  ulcer  at 
each  sitting,  until  gradually  the  whole  surface  is  brought  to  heal. 
The  cicatrix  left  is  soft  and  skin-like.  In  the  early  period  of  the 
growth  the  application  for  a  few  seconds  of  the  carbonic  acid  snow 
gives  rise  to  healing  in  some  cases. 

Plexiform  Neuroma,  or  Neuro-fibroma  is  a  rare  disease  of  the  eye- 
lids. It  is  S8311  as  a  congenital  growth  wliich  slowly  increases  in  size. 
The  tumour  in  general  is  soft  to  the  touch,  but  contains  many  hard  strings 
and  knobs.  Pressure  on  it  is  painful  in  some  cases.  It  may  attain  great 
size,  and  may  extend  to  the  supra-orbital,  temporal,  and  malar  regions, 
giving  rise  to  much  disfigurement.  Operation  is  indicated  only  if  the 
tumour  be  markedly  progressive,  as  a  satisfactory  result  is  not  very  easily 
attainable,  and  gangrene  has  followed  in  some  cases,  while  in  others,  where 
the  growth  had  to  be  followed  deeply,  severe  haemorrhage  has  occurred. 
In  some  instances  the  tumour  has  invaded  the  orbit,  and  even  the  cavity 
of  the  skull,  after  absorption  of  the  orbital  roof.  Plexiform  neuroma  is 
often  accompanied  with  buphthalmos. 

Lymphoma  or  Lymphadenoma  of  the  eyelids  usually  occurs  as  a 
bilateral  and  symmetrical  disease,  but  it  does  occur,  in  rare  instances,  on  one 
side  only.  It  is  frequently  associated  with  leucaemia,  or  pseudo-leucaemia, 
or  it  may  be  found  in  apparently  healthy  individuals.  It  often  invades 
the  orbit,  and  its  growth  is  exceedingly  slow  and  quite  painless. 

Epithelioma,  Sarcoma,  and  Lupus  are  all  seen  in  the  eyelids,  but 
require  no  special  description  here. 

Gangrene  of  the  Eyelid  is  a  rare  condition.  It  may  occur  as  a 
consequence  of  an  infected  wound  of  the  lid,  or  from  some  general  infection 
of  the  system,  even  in  influenza,  and  has  been  seen  as  a  result  of  excessive 
use  of  iced  compresses. 

Clonic  Cramp  of  the  Orbicularis  Muscle,  or  of  a  portion  of  it, 
is  often  seen,  and  is  popularly  known  by  the  name  of  '  life  '  in  the 
eyelid.  It  is  frequently  due  to  ovei-use  of  the  eyes  for  near  woik, 
especially  by  artificial  light,  or  if  there  be  defective  amplitude  of 
accommodation. 

Treatment  should  consist  in  the  regulation  of  the  use  of  the  eyes 
for  near  work,  and  the  correction  by  glasses  of  any  defect  in  the 
accommodation. 


554  DISEASES    OF    THE   EYE.  [chap,  xviir. 

Blepharospasm,  or  Tonic  Cramp  of  the  Orbicularis  Muscle,  is 

commonly  the  result  of  irritation  of  the  ophthalmic  division  of 
the  fifth  nerve  by  reflex  action,  as  in  phlyctenular  ophthalmia 
(p.  104)  and  some  other  corneal  and  conjunctival  affections  ;  or 
from  foreign  bodies  on  the  conjunctiva  or  cornea,  etc.  ;  or  it  may 
continue  for  some  time  after  the  relief  of  any  such  irritation.  It 
occurs,  also,  independently  of  such  causes,  and  is  then  difficult 
to  account  for,  unless  as  a  hysterical  symptom.  Yet,  even  in  these 
obscure  cases,  the  spasm  is  probably  often  a  reflex  from  the  fifth 
nerve  {i.e.  teeth,  or  nose),  and  it  will  be  found  that  pressure  upon  the 
supra-orbital  nerve  at  the  supra-orbital  notch  may  arrest  the  spasm  ; 
or,  if  not  there,  then  pressure  on  the  infra-orbital,  temporal,  malar, 
or  inferior  alveolar  branch  may  have  the  desired  effect. 

Treatment. — If  the  cause  of  the  reflex  cannot  be  ascertained,  or 
if  it  have  passed  away,  and  if  the  cramp  be  still  very  distressing, 
stretching  or  resection  of  the  branches  of  the  fifth  nerve,  from  which 
the  reflex  proceeds,  may  be  tried.  The  operation  of  spino-facial 
anastomosis  has  been  successfully  employed  in  some  obstinate  cases. 

Ptosis  (tttojo-i?,  a  fall),  or  Blepharoptosis,  is  an  inability  to  raise 
the  upper  lid,  which  then  hangs  down  over  the  eyeball.  It  is  either 
congenital  or  acquired;  and  in  the  latter  case  is  most  usually  the 
result  of  paralysis  of  the  branch  of  the  third  nerve  supplying  the 
levator. 

Persons  affected  with  ptosis  involuntarily  endeavour  to  raise  the 
eyelid  by  an  over-action  of  the  frontalis  muscle.  The  drooping  lid 
and  elevated  eyebrow  give  a  peculiar  and  characteristic  appearance. 

Paralytic  Ptosis. — The  Causes  of  Paralytic  Ptosis  are  similar  to 
those  of  paralysis  of  other  branches  of  the  third  pair,  more  especially 
exposure  to  cold  draughts  of  air  while  the  body  is  heated,  and 
syphilis  or  rheumatism  affecting  the  branch  to  the  levator  palpebrae 
in  its  course.  It  may  also  be  due  to  cerebral  disease  (p.  500). 
The  branch  to  the  levator  may  be  paralysed  alone,  or  in  conjunc- 
tion with  other  third-nerve  branches,  especially  to  the  superior 
rectus,  and  the  loss  of  power  may  be  partial  or  complete. 

Some  cases  of  bilateral  ptosis  in  elderly  people  due  to  primary 
atrophy  of  the  levator  palpeV)r?o  muscles  have  been  recorded.  The 
eyelids  were  elongated  and  thinned,  so  that  the  eyeball  showed 
plainly  through  them.  The  loss  of  power  had  in  each  case  been  very 
slowly  increasing  for  many  years. 


CHAP,   xviii.]  THE   EYELIDS.  555 

The  Treatment  of  a  recent  case  of  ordinary  paralytic  ptosis  de- 
pends upon  its  cause.  If  this  be  syphilis,  then  a  course  of  mercurial 
inunctions  or  of  iodide  of  potassium  ;  if  rheumatism,  salicylate  of 
soda  or  iodide  of  potassium — with,  in  either  case,  protection  of  the 
eye  and  side  of  the  head  by  means  of  a  warm  dressing  and  bandage. 
Cases  in  which  these  remedies  have  failed,  and  which  have  become 
chronic,  often  demand  operative  treatment.  Attempts  have  been 
made,  with  success  in  some  cases,  to  obviate  the  inconvenience  of 
ptosis  by  giving  support  to  the  lid  by  wire  splints  worn  like  an  eye- 
glass, or  attached  to  the  upper  edge  of  spectacle-frames. 

Ptosis  due  to  a  cerebral  lesion  rarely  comes  within  the  scope  of 
treatment.! 

Congenital  Ptosis  is  generally  present  in  both  eyes.  It  is 
sometimes  hereditary,  and  is  often  associated  with  paralysis  or 
defects  of  the  ocular  muscles  and  with  epicanthus  (p.  505).  It  is 
due  in  some  cases  to  an  imperfect  development  of  the  levator 
palpebrae,  and  in  others  to  an  abnormal  insertion  of  this  muscle, 
its  tendon  being  attached  to  the  tarsus  too  far  back.  Aplasia  of  a 
portion  of  the  nucleus  of  the  third  nerve  has  been  found  in  some 
cases. 

Operative  treatment  is  indicated  in  cases  of  paralytic  ptosis — 
where  other  measures  have  produced  no  result — in  ptosis  adiposa, 
and  in  congenital  cases.  Operations  for  ptosis  are  very  numerous, 
but  are  based  on  three  main  ideas,  namely  {a)  shortening  the  eyelid 
by  removal  (Fergus)  or  displacement  (Hess)  of  tissues,  or  by  making 
use  of  the  levator  palpebrae  (Everbusch)  ;  (6)  calling  in  the  aid  of  the 
frontalis  muscle,  and  (c)  substituting  a  portion  of  the  superior 
rectus  (Motais). 

A  very  common  proceeding  consists  in  the  excision  of  a  suffi- 
ciently large  oval  piece  of  integument,  its  long  axis  lying  in  the  length 
of  the  lid,  with  the  subcutaneous  connective  tissue  and  fat,  and,  in 
paralytic  cases,  a  small  portion  of  the  orbicular  muscle.  The  fold 
of  integument  to  be  abscised  is  seized  by  two  pairs  of  forceps — one 
of  them  held  by  an  assistant — at  the  inner  and  outer  ends  of 
the  lid,  and  by  this  means  the  necessary  size  of  the  fold  is  estimated. 
The  abscission  of  the  fold  is  performed  with  a  pair  of  scissors,  the 

1  Tho  value  of  ptosis  as  a  localising  symptom  in  cerebral  disease  is 
treated  of  in  chap,  xvii. 


DISEASES    OF    THE   EYE. 


[chap.    XVill. 


margin  of  the  wound  lying  close  to  the  points  of  the  forceps. 
The  subcutaneous  tissue,  etc.,  is  then  removed,  and  the  edges  of 
the  wound  drawn  together  by  a  few  points  of  suture.  This  is, 
however,  a  rather  crude  method,  and  should  only  be  employed,  if 
at  all,  in  slight  cases. 

Motais'  Operation. — This  operation  has  for  its  object  the  trans- 
plantation into  the  upper  lid  of  a  flap  taken  from  the  superior 

rectus  muscle  ;  consequently  it  is  only 
suitable  for  cases  of  ptosis  in  which 
there  is  no  paralysis  of  the  superior 
rectus.  In  such  cases  the  result  is  very 
satisfactory,  and  the  movements  of  the 
lid  follow  those  of  the  eyeball  better 
than  they  do  after  other  operations 
for  ptosis.  Fig.  230  shows  the  perfect 
elevation  of  the  lid  on  looking  up. 

The  upper  lid  is  everted,  and  the 
upper  fornix  is  stretched  between  two 
sharp  hooks,  one  being  inserted  into 
the  sclerotic  above  the  cornea,  and  the 
other  into  the  ciliary  margin  of  the 
everted  lid.  The  conjunctiva  is  then 
divided  over  the  insertion  of  the  superior 
rectus,  the  incision  being  carried  beyond  the  lateral  limits  of  the 
tendon,  which  is  exposed  by  separating  the  sub-con junctival  tissue, 
and  capsule  of  Tenon.  The  tendon  is  raised  on  a  large  strabismus 
hook  passed  under  it  from  the  inner  side,  and  it  is  seized  at  its 
centre  about  4  mm.  from  its  insertion  with  a  double-toothed  forceps, 
so  that  an  incision  may  be  made  with  scissors  in  its  centre  in  front 
of  the  forceps,  quite  close  to  the  sclerotic,  and  4  mm.  in  width.  The 
sectioned  portion  of  the  tendon  is  then  seized  with  a  broad-ended 
fixation  forceps,  so  as  to  stretch  it  out  well ;  and  with  straight 
scissors  two  parallel  incisions  are  made  upwards,  one  at  each  side 
of  the  tendon,  so  that  a  flap  1  cm.  long  may  be  formed  in  the  tendon. 
A  catgut  suture  with  two  curved  needles  is  passed  through  the  flap 
near  its  free  margin,  and  tied  firmly  on  the  flap.  The  central  part 
of  the  conjunctival  fornix  is  incised  with  the  curved  scissors,  and 
the  ])lades  are  passed  between  the  tarsus  and  the  soft  tissues  of  the 
eyelid  as  far  as  the  ciliary  margin,  so  as  to  make  a  path  for  the  flap 


Fig.  230.— Result  of  Motais' 
operation  in  right  eye. 


CHAP.    XVITT. 


THE   EYELTDS. 


657 


of  tendon.  One  of  \hv  iicedk's  cunying  its  end  of  tlio  suhirc  is  then 
passed  along  the  patli  thus  made,  and  caused  to  emerge  through  the 
skin  near  the  ciliary  margin.  The  second  needle  is  passed  in  the 
same  way,  its  point  of  exit  being  a  few  millimetres  from  that  of  the 
first.  The  ends  are  tied  over  a  pledget  of  lint,  and  by  this  means 
the  lid  will  be  drawn  up  and  the  ptosis  relieved.  The  conjunctival 
wound  is  united  with  catgut.  To  prevent  lagophthalmos,  the  lower 
lid  is  raised  until  it  comes  in  contact  with  the  upper  lid,  by  means 
of  a  suture  passed  through  the  former  near  its  ciliary  margin,  and  then 
through  the  skin  of  the  eyebrow  where  it  is  tied. 

EvershuscJis    Operation    for    Congenital    Ptosis    (Figs.    231    and 


Fio.  231.  Fig.   232. 

I,  levator  palpebrae  ;    o,  orbicularis. 


232). — The  object  of  the  operation  is  to  increase  the  powder  of  the 
levator  by  advancing  its  insertion,  or  rather  by  doubling  it  down 
over  the  tarsus,  to  wdiich  it  forms  fresh  adhesions.  Knapp's  lid- 
clamp  is  applied,  the  plate  being  pressed  w^ell  up  into  the  fornix  ;  and, 
before  the  ring  is  screwed  down,  the  skin  of  the  lid  is  drawn  down, 
so  that  its  prolongation  just  under  the  eyebrow  may  be  forced  into 
the  instrument.  The  skin  and  the  underlying  orbicularis  are  now 
divided  in  the  entire  width  of  the  lid,  parallel  to  its  free  margin,  and 
at  a  distance  half-w^ay  between  this  margin  and  the  eyebrow.     The 


558  DISEASES    OF    THE   EYE.  [ckav.   xviii. 

skill  and  subjacent  muscle  are  then  separated  up,  both  upwards  and 
downwards,  for  4  mm.  in  each  direction,  so  that  the  insertion  of  the 
levator  may  be  well  exposed.  A  suture  with  a  small  curved  needle 
at  either  end  is  then  introduced,  by  means  of  one  of  these  needles, 
horizontally  into  the  tendon  at  its  insertion,  and  near  the  centre  of 
the  latter,  in  such  a  way  that  about  2J  mm.  of  the  tendon  may  be 
included  in  the  suture.  Each  needle  is  now  passed  vertically  down- 
wards between  the  tarsus  and  orbicularis,  and  brought  out  at  the 
free  margin  of  the  lid  at  a  distance  from  each  other  of  about  2  J  mm. 
Two  more  such  double  sutures,  one  in  the  temporal,  the  other  in  the 
nasal,  third  of  the  tendon,  are  similarly  applied.  The  margins  of 
the  horizontal  skin  and  muscle  wound  are  now  drawn  together,  and 
then  the  three  sutures  are  closed  tightly.  It  is  desirable  to  slip  glass 
beads  over  the  ends  of  the  sutures  before  tying  them,  to  prevent 
cutting  into  the  margin  of  the  lid.  Both  eyes  are  bandaged,  and 
the  sutures  are  left  in  for  a  week  or  more. 

While  the  foregoing  and  other  operations  relieve  the  ptosis, 
they  are  liable  to  give  rise  to  some  unsightly  cicatrices,  and  are 
sometimes  not  permanent  in  their  effect.  With  a  view^  to  obviate 
these  drawbacks,  Carl  Hess  has  devised  the  following  operation. 

Hess'  Operation. — The  eyebrow  having  been  shaved,  an  incision 
{a  a,  Fig.  233)  is  made  in  its  whole  length,  and  carried  through  the 
skin  and  subcutaneous  tissue  ;    and,  starting  from  this  incision,  the 

skin  of  the  lid  is  separated  with  the 

"  '■W(^(itkir--    "  scalpel  from  the  underlying  orbicular 

J0^^  ^  ^^^5^  muscle  nearly  as   far  as   the  ciliary 

margin    (dotted    line   in    Fig.    233). 
b."^     ' — '     — '  /  When   the    haemorrhage  has  ceased, 

:-^^^..    _ ■-':^J<i^^  three  silk  sutures,  each  armed  with 

??^J^7//^^  two  needles,  are  introduced,  one   at 

the  centre  and   one    towards   either 
Fig.  233.  ^^^^   o^   ^^^    eyelid,  and  about   half- 

way between  the  eyebrow  and  lid 
margin  (6,  Fig.  233),  or  somewhat  nearer  the  latter.  The  needles 
of  each  suture  are  inserted  about  5  mm.  apart,  and,  being  passed 
from  without  inwards  through  the  skin,  they  are  brought  out 
in  the  space  made  by  the  skin  dissection.  The  needles  are  now 
passed  deeply  under  the  upper  border  of  the  incision  in  the 
eyebrow,  and  brought  out  a  few  millimetres  above  it  (at  points 


CHAP,   xviir.]  THE     EYELIDS.  559 

repie«ontc(.l  by  tliiee  pairs  of  duts  in  Fig.  2:3:^).  The  two  ends  uf 
eac-li  suture  are  tied  over  a  small  roll  of  lint  or  a  Int  of  rubber  drainage 
tube,  and  drawn  tightly  enough  to  relieve  the  ptosis  by  producing 
a  fold  in  the  skin  flap.  The  wound  in  the  eyebrow  is  united  by 
some  points  of  suture.  The  sutures  are  allowed  to  remain  for  eight 
or  ten  days.  The  permanent  result  depends  on  the  union  and 
cicatrisation  of  the  extensive  raw  surfaces  in  their  new  position. 
The  operation  causes  little  or  no  disfigurement,  as  the  artificial  fold 
falls  in  about  the  same  situation  as  that  which  is  present  in  the  normal 
eyelid  ;  while  the  cicatrix  in  the  eyebrow  is  concealed  by  the  hairs 
when  they  have  grown  again.  In  Figs.  234  and  235  a  section  of  the 
eyelid  before  and  after  tightening  of  the  sutures  is  represented. 


ixa 


Fig.  234.  Fig.  235. 

Fig.  234. — The  needles  are  passed  in  at  a  through  the  skin  of  the 
nd,«and  brought  out  at  a'  through  the  skin  and  subcutaneous  tissue  above 
the  eyebrow. 

Fig.  235. — When  the  sutures  are  tightened  a  is  closely  approximated 
to  a'. 

Freeland  Fergus'  Operation. — This  operation  is  employed  for  all 
kinds  of  ptosis.  It  can  be  performed  painlessly  by  infiltration  of 
the  eyelid  with  a  weak  solution  of  eucaine.  The  eyelid  is  stretched 
upon  a  spatula  inserted  under  it,  and  an  incision  is  made  parallel 
to,  and  a  few  millimetres  distant  from,  the  edge  of  the  lid.  The 
incision  extends  from  end  to  end  of  the  eyelid,  and  is  carried  through 
the  skin  and  muscle.  A  second  incision  is  made,  extending  nearly 
in  a  semicircle  from  one  extremity  to  the  other  of  the  first  incision. 
It  also  is  carried  through  the  skin  and  muscle,  which  are  then  dis- 
sected off  the  face  of  the  tarsus.  A  portion  of  the  tarsus  is  now 
excised  along  with  the  conjunctiva  adherent  to  it,  the  extent  of 
this  excision  depending  upon  the  amount  of  effect  desired.     When 


5lK)  DISEASES    OF    THE   EYE.  [chap,   xviit. 


the  ptosis  is  almost  total,  nearly  the  whole  of  the  tarsus  above 
the  first  incision  is  removed.  In  lesser  degrees  of  ptosis  smaller 
excisions  suffice.  Six  sutures  are  finally  inserted,  three  deep  and 
three  superficial.  The  deep  sutures  are  best  made  of  absorbent 
sterilised  catgut.  The  superficial  ones  can  be  of  this  material  or  of 
silk.  The  three  deep  sutures  are  used  to  unite  the  tough  fibrous 
membrane  which  passes  from  the  occipito-frontalis  to  the  eyelid 
with  that  portion  of  the  tarsus  which  remains  in  the  lid  below  the 
level  of  the  first  incision.  The  superficial  sutures  are  employed  to 
unite  the  edges  of  the  skin  wound.  The  operation  gives  great 
mobility  to  the  eyelid. 

A  remarkable  and  rare  condition  is  Congenital  Ptosis,  with  Associated 
Movements  of  the  Affected  Eyelid,  during  the  action  of  certain  muscles.  It 
is  most  commonly  the  left  lid  which  is  affected,  and  the  paralysis  may  be 
congenital  or  acquired.  Three  conditions  have  been  observed — viz. 
(1)  elevation  of  the  drooping  lid  when  the  eye  is  adducted,  (2)  when  the 
eye  is  abducted,  or  (3)  when  the  mouth  is  opened.  A  synchronous  con- 
traction of  the  pupil  has  been  noticed  in  some  cases,  while  in  some  the 
elevation  of  the  lid  occurs  also  with  a  lateral  motion  of  the  jaw,  and  with 
deglutition.  Gower's  explanation  is  that  in  these  cases  the  levator  is 
not  wholly  supplied  by  the  third  nerve,  but  partly  also  by  nerve  fibres 
which  take  their  origin  in  the  nucleus  of  the  fifth  pair,  and  which  also 
supply  the  external  pterygoid  and  digastric  muscles.  But  this  theory  does 
not  hold  good  in  all  cases,  for  Bull  describes  a  case  in  which  the  lid  was 
raised  when  the  head  was  bent  back,  thus  stretching  the  digastric,  and  he 
regards  these  as  associated  or  reflex  movements.  In  some  instances  the 
lid  can  be  raised  voluntarily  on  closing  the  other  eye.  Needless  to  say, 
no  remedy  can  be  applied  for  relief  of  this  condition. 

Ptosis  Adiposa  is  a  rather  rare  condition  which  occurs  in  young 
people.  The  skin  of  the  eyelid  is  puffed  out,  is  slightly  hypersemic 
and  finely  wrinkled,  and  on  palpation  no  feeling  of  resistance  is  felt,  nor  is 
there  any  pitting  on  pressure.  We  have  operated  on  four  such  cases, 
and  in  all  we  removed  from  under  the  orbicularis  a  roll  of  fat,  which 
was  quite  well  defined,  but  appeared  to  be  continuous  with  the  orbital 
fat  at  the  inner  side  only.  These  cases  somewhat  resemble,  and  are 
sometimes  grouped  with,  the  cases  of  blepharo-chalazis  which  occur  in 
old  people,  and  in  which  the  skin  of  the  upper  lid  hangs  loosely  over  the 
tarsal  portion  of  the  hd. 

Hysterical  Ptosis  may  be  unilateral  or  bilateral.  It  is  not  a  true  ptosis, 
but  is  caused  by  a  slight  spasm  of  the  orbicularis,  and  in  consequence 
the  eyebrow  on  the  affected  side  is  always  lower  than  on  the  other,  exactly 
the  reverse  of  the  state  of  affairs  in  paralytic  ptosis.  For  Sympathetic 
Ptosis,  see  p.  501. 

The  term  ptosis  is  also  given,  although  not  very  correctly,  to  cases  in 
which  increased  weight  of  the  lid  from  inflammation,  oedema,  or  tumours, 
causes  it  to  droop. 


CHAP.   xvTTT.l  THE    EYELIDS.  r^(^\ 

*  LagOphthallUOS  (Au-yws,  a  hare,  us  it  was  suppused  tliat  this 
animal  sleeps  with  its  eyes  open  ;  o<^^uA/xos),  or  inability  to  close  the 
eyelids,  is  most  commonly  due  to  paralysis  of  the  portio  dura,  and 
is  then  associated  with  the  other  symptoms  of  the  latter  affection. 
On  an  effort  to  close  the  lids  being  made,  the  eyeball  is  rotated  up- 
wards under  the  upper  lid,  owing  to  the  associated  action  of  the 
superior  rectus  ;  and  in  sleep  this  upward  rotation  also  occurs — a 
fact  which  explains,  to  a  great  extent,  the  immunity  of  the  cornea 
from  ulceration  in  many  of  these  cases.  Lagophthalmos  may  also 
be  due  to  orbital  tumours  pushing  the  eyeball  forwards,  to  exoph- 
thalmic goitre,  to  staphyloma,  or  to  intra-ocular  growths  distending 
the  walls  of  the  eyeball — in  all  of  which  conditions  the  eyelids  are 
often  mechanically  prevented  from  closing  over  the  eyeball,  or  can 
be  closed  only  by  a  strong  effort  of  the  will.  The  danger  to  the  eye 
depends  upon  the  tendency  to  ulceration  of  the  cornea  from  its 
dryness,  caused  by  exposure  to  the  air,  and  from  foreign  substances 
not  being  removed  from  it  by  nictitation. 

In  cases  of  non-paralytic  lagophthalmos,  protection  of  the  cornea 
by  keeping  the  eyelids  closed  with  a  bandage,  or  by  inserting  a  few 
epidermic  sutures  in  the  margins  of  the  eyelids  to  draw  them 
together,  should  be  our  first  care.  Tarsoraphy  may  be  employed 
in  those  cases  where  circumstances  indicate  that  it  would  be  useful 
— e.g.  in  some  cases  of  exophthalmic  goitre,  or  of  staphylomatous 
eyeball. 

In  paralytic  cases,  the  primary  cause  of  the  paralysis  (syphilis, 
rheumatism,  etc.)  must  be  treated  so  long  as  there  is  a  prospect  of 
restoring  power  to  the  muscle.  Locally,  galvanism  and  hypodermic 
injections  of  strychnia  may  be  employed.  During  cure  the  cornea 
should  be  protected  as  above.  In  incurable  cases,  the  opening  of  the 
eyelids  must  be  reduced  considerably  in  size  by  an  extensive  tarso- 
raphy performed  according  to  one  of  the  following  methods. 

The  Operation  of  Tarsoraphy  consists  in  uniting  the  margins  of 
the  upper  and  lower  lids  in  the  neighbourhood  of  the  external  com- 
missure, so  as  to  reduce  the  size  of  the  opening  of  the  eyelids.  The 
commissure  should  be  caught  between  the  finger  and  thumb,  and 
the  edges  of  the  lids  approximated,  so  as  to  enable  the  operator  to 
form  an  estimate  of  the  required  extent  of  the  operation.  A  horn 
spatula  is  then  passed  behind  the  commissure,  and  the  necessary 
length  of  the  margin  of  each  lid,  including  the  bulbs  of  the  cilia, 
36 


56^  DISEASES   OF    THE   EYE.  [chap,   xvtii. 


is  abscised  with  a  sharp  knife.     The  raw  margins  are  then  brought 
together  with  sutures. 

Priestley  StnitJis  Method. — Both  lids  are  split  rather  deeply  by 
intermarginal  incisions  {a,  Fig.  236),  and  sutures  are  then  passed 
in  such  a  way  as  to  draw  together  the  bottoms  of  the  two  grooves. 
When  the  sutures  are  tied,  the  anterior  and  posterior  lips  of  the 
incisions  are  flattened  out  (c,  Fig.  236),  and  thus  a  broad  contact  is 
obtained  between  the  two  raw  surfaces.  Two  or  more  sutures  may 
be  applied. 


■r^^-^-^^ 


ib)  ic) 

Fig.  236. 

(a)  Shows  incisions  and  method  of  inserting  suture  ;  (6)  front  view 
and  (c)  side  view  (section)  when  sutures  are  tied. 

Pfluger's  Method  consists  in  passing  one,  two,  or  even  three  double 
sutures  subcutaneously  around  the  eyelids,  about  5  mm.  from  their 
margins.  The  ends  are  drawn  together,  so  that  the  eye  is  concealed 
by  the  pouch  thus  formed,  and  tied.  From  time  to  time  the  sutures 
are  tightened,  until  finally  they  cut  through,  and  by  this  means  a 
subcutaneous  ring-cicatrix  is  produced.  Should  the  first  ring- 
cicatrix  not  sufficiently  close  the  eyelids,  the  operation  can  be  re- 
peated even  more  than  once  again.  The  method  is  tedious  and 
painful. 

Symblepharon  (o-vV,  together ;  jSXecfiapov,  the  eyelid)  is  an  ad- 
herence, partial  or  complete,  of  the  eyelid  to  the  eyeball.  It  is 
usually  the  result  of  burns  of  the  conjunctiva  by  fire  or  caustic 
substances.  The  shortening  of  the  conjunctival  sac,  which  is  seen 
as  the  result  of  pemphigus  (p.  89)  or  of  granular  ophthalmia,  and 
which  is  described  under  the  heading  of  Xerophthalmos  (p.  96),  is 
not  properly  termed  symblepharon.  If  the  symblepharon  interfere 
seriously  with  the  motions  of  the  eyeball,  or  if  it  cause  defect  of 
vision  by  obscuring  the  cornea,  it  becomes  desirable  to  relieve  it  by 
operation.     Should  it  consist  of  a  simple  band  stretching  from  lid 


PTTAr.     XVTTT. 


THE    EYETADS. 


563 


to  eyeball,  it  iimy  be  .severed  by  lig;itiiie,  and  d  the  baud  be  biuad, 
two  ligatures  may  be  employed,  one  for  eitlier  half.  A  syudjlepharou 
wluch  oceupies  a  considerable  surface  cannot  be  got  rid  of  in  this 
way ;  and  for  such  eases  a  transplantation  procedure  like  that  of 
Teale  may  be  employed,  the  great  difficulty  in  dealing  with  these 
cases  being  the  tendency  there  is  to  re-union  of  the  surfaces,  unless 
one  or  both  of  them  be  carpeted  with  epithelium. 

In  Teale's  Operation,  if  we  suppose  the  case  to  be  similar  to  that 


Fig.  237. 


Fig.  238. 


represented  in  Fig.  237,  an  incision  is  carried  along  the  line  of  the 
margin  of  the  cornea  at  A,  through  the  whole  thickness  of  the 
symblepharon,  and  the  lid  is  dissected  off  from  the  eyeball  as  far  as 
the  fornix.  Two  conjunctival  flaps  are  now  formed,  as  at  B  and  C 
in  Fig.  238,  and  one  of  them  {B)  is  turned  to  form  a  covering  for  the 
wounded  surface  of  the  inside  of  the  eyelid,  while  the  other  (0)  is 
used  to  cover  the  bulbar  surface  (Fig.  239),  the  flaps  being  held  in 
their  places  by  fine  sutures.  That  part  of  the  symblepharon  which 
is  left  adherent  to  the  cornea  soon  atrophies  and  disappears.  No 
great  tension  of  the  flaps  should  exist 
as  they  lie  in  their  new  positions. 

Teale,  again,  has  suggested  the 
formation  of  a  bridge-like  conjunc- 
tival flap  above  the  cornea,  and  the 
removing  of  it  across  the  latter  to 
cover  the  loss  of  substance  situated 
below\  After  the  sutures  which  keep 
the  flap  in  its  place  have  been  introduced,  the  latter  is  separated 
at  its  bases. 

A  simple  plan,  which  w^ould  be  applicable  to  such  a  case  as  that 
depicted  in  Fig.  237,  where  the  adhesion  is  not  very  extensive,  and 
perhaps  even  to  some  more  extensive  ones,  consists  in  dissecting  the 


Fig.  239. 


")r)4  DISEASES    OF    THE   EYE.  [CHAr.   xvitt. 


cuiijuiietival  process  off  the  cornea,  and  tlicn  tiuning  it  down  on 
the  raw  inner  surface  of  the  under  lid,  and  fastening  it  there  with  a 
suture  or  two.     We  have  done  this  with  complete  satisfaction. 

Harlan'' s  Operation.- — This  is  specially  applicable  to  extensive 
symblepharon  of  the  lower  lid,  and  differs  from  the  foregoing  opera- 
tions in  that  it  provides  a  covering  of  skin,  and  not  of  mucous  mem- 
brane, for  the  raw  surface  of  the  under  lid.  Operations  on  the  same 
principle  have  been  proposed  by  Snellen  and  by  Kuhnt.  An  in- 
cision (A  B,  Fig.  240)  through  the  whole  thickness  of  the  eyelid,  and 
corresponding  in  length  with  the  latter,  is  made  along  the  lower 
margin  of  the  orbit.  Below  this  a  skin  flap  (C  D )  is  then  formed.  The 
flap  is  dissected  up,  and  the  incisions  are  carried  a  little  more  deeply 
as  A  B  is  approached,  to  enable  the  flap  to  turn  the  more  readily. 
The  flap  is  then  turned  up  as  on  a  hinge,  slipped  through  the  button- 
hole, and  sutured  securely  to  the  inner  surface  of  the  under  lid. 
After  a  time  the  skin  surface  turned  towards  the  eyeball  becomes 

considerably  modified,  so  as  to  be 
somewhat  like  mucous  membrane. 
The  bare  space  left  by  the  removal 
of  the  strip  of  skin  is  covered  with- 
out strain  by  making  a  small  hori- 
zontal incision  (D  E)  at  its  -outer 
Fig  "iicT  extremity,    and    forming     a    sliding 

flap. 
Trails  plantation  Operations. — The  transplantation  of  mucous 
membrane  from  the  lips  or  cheek  has  been  used  in  extensive  symble- 
pharon, but  the  drawback  to  mucous  membrane  flaps,  where  two 
opposing  surfaces  have  to  be  covered,  is  that  when  the  superficial 
epithelium  of  the  mucous  membrane  is  thrown  oft'  there  is 
danger  of  the  surfaces  uniting.  Thiersch  and  other  skin  flaps  are 
preferable. 

Blepharophimosis  {(3Xl4)apov,  eyelid;  (fil/jnoo-L^,  narrowing]  is  a 
contraction  of  the  outer  commissure  of  the  lids,  with  consequent 
diminution  in  size  of  the  opening  between  the  latter ;  and  is  com- 
monly due  to  shortening  of  the  skin,  from  long-continued  irritation, 
caused  by  the  discharge  in  a  case  of  very  chronic  conjunctivitis. 

It  is  remedied  by  a  Canthoplastic  Operation.  The  outer  com- 
missure is  divided  in  its  entire  thickness,  in  a  line  which  is  a  pro- 
longation of  the  line  of  junction  of  the  lids  when  closed,  by  a  single 


CilAl'.    XVIII. 


THE   EYELIDS. 


565 


stroke  of  strong  straight  scissors,  one  blade  of  which  has  been 
passed  behind  the  commissure.  The  integiimental  incision  should 
be  made  a  little  longer  than  that  in  the  conjunctiva.  An  assistant 
then  draws  the  upper  lid  up  and  the  lower  lid  down,  so  as  to  make 
the  wound  gape.  The  conjunctival  margin  and  the  dermic  margin 
are  now  united  in  the  centre  by  a  point  of  suture  (C,  Fig.  241),  while 
two  more  sutures  (A  and  B)  are  applied,  one  above  and  the  other 
below  the  first.     This  operation  is  also  employed  in  cases  of  granular 


Fig.  241. 

ophthalmia  and  of  purulent  conjunctivitis,   when  it  is  desired  to 
relieve  pressure  of  the  eyelid  on  the  globe. 

Distichiasis  (St's,  tivice ;  aTL^o^,  a  row)  and  Trichiasis  {rplxos,  a 
hair). — The  first  of  these  terms  iirdicates  the  growth  of  a  row  of 
eyelashes  along  the  intermarginal  por-tion  of  the  lid  in  addition  to 
the  normal  row  ;  while  trichiasis  indicates  a  false  direction  given 
to  the  true  cilia.  Both  conditions  are  often  found  co-existing,  and 
often,  too,  they  are  present  along  with  entropion.  They  may  both 
be  produced  by  chronic  blepharitis  (p.  543),  or  by  chronic  granular 
ophthalmia  (p.  73).  Some  cases  of  congenital  distichiasis  and 
trichiasis  have  been  recorded.  The  symptoms  the  false  cilia  produce, 
and  the  dangers  to  the  eye  attendant  on  them,  are  due  to  their 
rubbing  on  the  cornea,  which  causes  pain,  blepharospasm,  and 
opacity  of  the  cornea,  or  even  ulceration  of  it. 


56C 


DISEASES   OF    THE   EYE. 


[chap,   xvrit. 


Operations  for  Distichiasis  and  Trichiasis  : — 

Epilation. — The  false  cilia  may  be  pulled  out  with  a  forceps  ;  but 
this  cannot  be  regarded  as  a  cure,  as  the  hairs  grow  again  ;  yet,  if 
repeatedly  removed,  they  grow  finer  and  finally  cease  to  be  renewed. 

Electrolysis. — A  needle  is  attached  to  the  negative  pole,  and  its 
point  passed  into  the  bulb  of  the  eyelash  to  be  removed,  the  positive 
pole  being  placed  on  the  temple.  On 
closure  of  the  circuit,  if  the  battery  be 
working  properly,  bubbles  of  gas  should 
rise  up  round  the  needle,  and  a  slough 
forming  at  the  root  of  the  hair,  the  latter 
becomes  loose,  and  is  removed.  It  does 
not  grow  again,  for  the  bulb  is  destroyed. 
Each  hair  must  be  separately  operated  on. 
proceeding  is  very  valuable  where  only  a  few 
are  to  be  dealt  with. 

Excision. — When  some  half-dozen  hairs  close 
together  are  growing  wrong,  the  simplest  and  best 
plan  is  to  completely  remove  them  by  excision  of 
the  corresponding  portion  of  the  ciliary  margin.  A 
fine  knife  is  passed  into  the  intermarginal  region 
at  the  place  corresponding  with  the  hairs  to  be  dealt 
with,  and  a  partial  division  of  the  lid  into  two 
layers,  as  in  the  Arlt-Jaesche  operation  [vide  infra), 
is  effected.  A  triangular-shaped  incision  in  the  skin 
of  the  lid  is  then  made,  including  the  erring  hairs, 
the  whole  flap  is  excised,  and  the  margin  of  the  loss 
of  substance  is  drawn  together  with  sutures. 

Transplantation,  or  Shifting,  of  the  marginal 
portion  of  the  integument  containing  the  hair  bulbs, 
true  and  false.  One  of  the  oldest  and  most  valuable 
operations  of  this  kind  is  that  of  Jaesche,  modified  by  Arlt.  It 
is  performed  as  follows  : — Knapp's,  or  Snellen's,  clamp  (Fig.  242) 
having  been  applied  to  prevent  bleeding,  the  lid  in  its  whole 
length  is  divided  in  the  intermarginal  part  into  two  layers  (Fig. 
243),  the  anterior  containing  the  orbicular  muscle  and  integument 
with  all  the  hair  bulbs,  the  posterior  containing  tlie  tarsus  and 
conjunctiva.  The  incision  in  the  intermarginal  portion  is  about 
5  mm.  deep.  'A  second  incision  is  now  made  through  the  integument 


Fig.  24: 


CHAP.    XV  11 1.] 


THE   EYELIDS. 


507 


of  the  lid,  parallel  to  its  margin,  and  from  5  to  7  mm.  removed  from 
it.  This  incision  also  extends  the  whole  length  of  the  lid.  A  third 
incision  is  cariied  in  a  curve  from  one  end  to  the  other  of  the  second 
incision.  The  height  of  the  curve  is  proportional  to  the  effect  re- 
quired, varying  from  4  mm.  to  7  mm.  The  piece  of  integument 
included  between  the  second  and  third  incisions  is  dissected  off  with 
forceps  and  scissors,  without  any  of  the  underlying  muscle  being 
touched,  and  the  margins  of  the  loss  of  substance  are  brought  to- 
gether by  sutures.  By  this  procedure  the  lower  portion  of  integu- 
ment, containing  the  hairs  and  their  bulbs,  is  drawn  up  and  away 
from  contact  with  the  cornea. 
After  this  operation  the  condition 
is  sometimes  liable  to  relapse. 

Van  Millingen^s  Operatio7i  con- 
sists in  splitting  the  eyelid,  as  in 
the  Arlt-Jaesche  operation,  from 
end  to  end,  sufficiently  to  produce 
a  gap  (5,  Fig.  244)  3  mm.  in  width 
at  the  central  part  of  the  lid,  and 
gradually  becoming  narrower  to- 
wards the  canthi.  The  gap  is 
usually  kept  open  by  sutures 
passed  through  folds  of  skin  on  the 
upper  lid  {a  a  a),  by  means  of 
which  also  the  lid  is  prevented 
from  closing  for  twenty-four  hours 
at  the  least,  but  we  have  not  found 
that  these  sutures  are  essential. 
As  soon  as  the  bleeding  has  ceased,  a 

strip  of  mucous  membrane  of  the  same  length  as  the  incision  in  the 
lid,  and  2  to  2J  mm.  in  breadth,  is  cut  out  with  two  or  three  snips 
of  a  curved  scissors  from  the  inner  surface  of  the  patient's  under 
lip,  on  which  an  eyelid  clamp  has  been  placed  to  prevent  bleeding, 
and  is  introduced  at  once  into  the  gap  in  the  intermarginal  space.  It 
should  then  be  pressed  into  position  with  a  probe.  According  to 
Van  Millingen,  sutures  are  superfluous  ;  but  they  are  desirable  for 
the  sake  of  security,  and  do  no  harm.  We  usually  employ  three 
sutures,  one  at  either  end  of  the  flap  and  one  in  the  centre ;  these 
sutures  are  not  tied  over  the  edges  of  the  flap,  the  mucous  membrraie 


Fig.  243. 


)68 


DISEASES    OF    THE   EYE. 


[chap.    XV  hi. 


Fig.  244. 


being  merely  held  in  place  by  a  knot  on  the  end  of  each  thread,  the 
needles  after  piercing  the  flap  being  carried  up  under  the  skin,  and 
the  free  ends  of  the  threads  are  then  loosely  tied  together  on  the 
outer  surface  of  the  skin.  It  is  important,  in  order  to  obtain  a 
neat  effect,  to  clean  the  fat  and  submucous  tissue  from  the  flap 

before  applying  it ;  and 
while  this  is  being  done 
the  flap  should  lie  on  a 
warm  porcelain  plate. 
The  eyelid  is  then  covered 
over  with  a  piece  of  lint, 
on  which  is  spread  a  thick 
layer  of  xeroform  vase- 
line, and  over  this  is 
placed  a  wad  of  cotton- 
wool and  a  bandage. 

It  is  not  advisable  to 
transplant  small  strips  of 
mucous  membrane  if  the 
trichiasis  be  partial,  as 
partial  trichiasis  is  often  only  the  commencement  of  complete 
trichiasis,  and  therefore,  in  these  cases,  the  filling  up  of  the  entire 
length  of  the  intermarginal  space  with  a  flap  of  mucous  membrane 
should  be  effected.  One  or  two  fine  sutures,  which  serve  to  unite 
the  margins  of  the  wound  in  the  lip,  arrest  the  bleeding  at  once, 
and  accelerate  union  of  the  part,  which  is  generally  completed  in 
twenty-four  hours. 

This  is  the  most  effectual  method  of  permanently  providing  a 
good  intermarginal  space,  and  in  thus  definitely  relieving  the  con- 
dition. 

Entropion  (er,  in;  Tpiiroj,  to  turn),  or  Inversion  of  the  Eyelid, 
is  due  to  organic  change  in  the  conjunctiva  or  tarsus,  or  to  spasm 
of  the  palpebral  portion  of  the  orbicular  muscle.  A  large  proportion 
of  the  former  class  of  cases  is  the  result  of  chronic  granular  ophthal- 
mia, and  is  most  common  in  the  upper  lid.  Spastic  entropion  occui's 
in  the  under  lid  only.  It  is  frequent  in  old  people  (senile  entropion) 
from  relaxation  of  the  skin  of  the  eyelid,  and  is  also  produced  by 
the  wearing  of  a  ])andage  after  operations. 

Treatment.— ~li  the   tarsus   of   the   upper   lid   be   not   distorted, 


CHAP.    XVIII.] 


THE   EYELIDS. 


.")()<) 


organic  entropion  can  often  be  corrected  by  one  of  the  methods 
described  for  trichiasis  and  distichiasis.  But  many  of  these  cases 
are  accompanied  by,  or  rather  due  to,  abnormal  curvature  with 
hypertrophy  of  the  tarsus. 

In  such  cases  the  operation  must  include  an  attack  on  the  tarsus 
itself. 

Snellen's  Operation. — An  eyelid  clamp  is  applied.  About  3  mm. 
from  the  margin  of  the  lid,  and  parallel  to  it,  an  incision  is  made 
through  the  skin  alone,  extending  the  whole  length  of  the  lid.  The 
orbicular  muscle  is  exposed  by  dissection  of  the  skin  upwards,  in 
order  to  promote  retraction  of  the  latter,  and  along  the  edge  of  the 
lower  margin  of  the  wound  a  strip,  about  2  mm.  broad,  of  the  orbicular 


Fig.  245. 


Fig.  24G. 


muscle  is  removed,  and  the  tarsus  to  the  same  extent  is  exposed  to 
view,  A  wedge-shaped  piece,  corresponding  with  the  exposed  part 
of  the  tarsus,  is  now  excised  from  it  with  a  very  sharp  scalpel,  the 
edge  of  the  wedge  pointing  towards  the  conjunctiva,  which  latter, 
however,  is  left  intact.  The  hypertrophy  of  the  tarsus,  which  is 
always  present,  facilitates  this  procedure.  A  silk  suture  carrying  a 
needle  on  each  end  having  been  prepared,  one  needle  is  passed  from 
within  outwards  through  the  band  of  muscle  and  integument  left 
at  the  margin  of  the  lid.  The  second  needle  is  also  passed  from 
within  outwards  through  the  upper  lip  of  the  tarsal  loss  of  substance, 
and  then  from  within  outwards  through  this  same  marginal  band, 
at  a  distance  of  about  -1  mm.  from  the  point  of  exit  of  the  first  needle. 
The  ends  of  the  suture  are  now  tied  together,  a  small  bead  having 
first  been  strung  on  each  to  prevent  it  from  cutting  through  the 


570  DISEASES   OF    THE   EYE.  [chap,  xviii. 


skin.  Three  such  sutures  are  employed.  The  accompanying  figures 
(245  and  246)  make  the  foregoing  description  more  intelligible. 

Berlin's  Operation. — An  eyelid  clamp  is  applied.  The  first  in- 
cision lies  3  mm.  above  the  margin  of  the  lid,  extends  its  whole 
length,  and  divides  it  in  its  entire  thickness,  including  the  conjunc- 
tiva. The  skin  and  muscle  at  the  upper  edge  of  the  wound  are 
pushed  or  dissected  up  so  as  to  expose  the  tarsus.  The  upper  edge 
of  the  tarsal  incision  is  now  seized  at  its  centre  with  a  finely  toothed 
forceps,  and  an  oval  piece  with  the  adherent  conjunctiva,  about  2  to 
3  mm.  wide  in  its  widest  part,  and  in  length  corresponding  with  that 
of  the  eyelid,  is  excised  from  it  with  a  fine  scalpel.  The  wound  is 
closed  with  three  sutures  through  the  skin.  If  it  be  thought  desirable 
to  increase  the  effect,  a  skin-flap  may  be  excised  from  the  lid.  The 
objection  to  this  operation,  that  a  portion  of  the  mucous  membrane 
is  removed,  is  not  of  importance.     The  method  is  a  good  one. 

Spastic  Entropion  of  the  lower  lid,  as  the  result  of  bandaging, 
usually  disappears  when  the  use  of  the  bandage  is  given  up  ;  or,  if 
the  bandage  must  be  continued  and  should  the  inverted  lid  cause 
irritation,  a  dermic  suture  at  the  palpebral  margin  which  is  fastened 
to  the  cheek  below  will  give  relief. 

Senile  Entropion  of  the  lower  lid  is,  of  the  spastic  kinds,  the  one 
which  most  commonly  needs  operative  interference.  The  methods 
in  general  use  for  it  are  : — 

The  Excision  of  a  Horizontal  Piece  of  Skin,  with  a  portion  of  the 
underlying  palpebral  part  of  the  orbicular  muscle,  so  as  to  give 
rise  to  sufficient  cicatricial  contraction  to  draw  the  margin  of  the  lid 
outwards. 

The  foregoing,  and  other  such  measures,  produce  a  good  result 
at  the  time,  but  are  sometimes  followed  by  recurrence  of  the  en- 
tropion. Hotz,  believing  the  cause  of  this  to  be  that  the  cicatrix, 
whether  dermic  or  dermo-muscular,  upon  which  the  result  depends, 
has  no  point  (Cappui ;  and  consequently,  while  it  may  draw  the 
eyelid  out,  is  liable  to  draw  the  skin  of  the  cheek  up,  and  thus  to 
neutralise  its  desired  effect,  has  proposed  the  following  ingenious 
operation  : — 

Hotz's  Operation. — A  horn  spatula  is  inserted  under  the  lid,  and, 
at  4  to  6  mm.  below  the  margin  of  the  latter,  a  horizontal  incision  is 
made  through  the  skin  from  the  inner  to  the  outer  end  of  the  lid. 
This  incision  is  at  the  boundary  between  the  palpebral  and  orbital 


CHAr.    XVIII.] 


THE   EYELIDS. 


171 


portions  of  the  orbicular  muscle,  and  just  over  the  lower  margin  of 
the  tarsus.  An  assistant  then  draws  the  upper  edge  {a,  Fig,  247)  of 
the  wound  upwards  with  a  forceps,  while  the  surgeon  draws  the 
lower  edge  (6)  downwards,  in  this  way  exposing  and  stretching  the 
orbicular  muscle.  A  few  strokes  of  the  knife  in  the  direction  of  the 
incision  -are  now  sufficient  to  separate  the  palpebral  portion  (/)  of 
the  muscle  from  the  orbital  portion  {f),  and  to  lay  bare  the  lower 
edge  of  the  tarsus  (<),  which  is  of  a  yellowish  tendinous  appearance. 
That  part  of  the  palpebral  portion  of  the  muscle  which  covered  the 
lower  edge  of  the  tarsus,  and  which  was  drawn  up  with  the  palpebral 
edge  of  the  first  incision,  is  now  removed  with  forceps  and  scissors, 

to  the  extent  of  about  2  mm.  in 
width,  through  the  whole  length 
of  the  lid.  All  such  muscular 
fibres,  also,  which  may  still  ad- 
here to  the  lower  third  of  the 
tarsus  must  be  carefully  cleaned 
off,  and  now  the  palpebral  skin 
may  be  brought  into  union  with 
the  tarsus.  Four  sutures  are 
generally  applied,  about  5  mm. 
apart.  The  needle  is  passed 
through  the  palpebral  skin,  close 
to  the  margin  of  the  wound 
The  bare  tarsal  edge  is  then  seized  in  the  forceps,  the  needle 
placed  perpendicularly  on  it  (at  d),  and  carried  through  it  by  a 
short  downward  curve  until  its  point  appears  (at  c)  below  the 
tarsus  in  the  tarso-orbital  fascia  (/).  The  needle  is  now  passed 
out  through  the  lower  edge  of  the  incision  (at  h),  care  being  taken 
that  none  of  the  fibres  of  the  orbital  portion  of  the  muscle  are 
included  in  the  suture.  Upon  the  suture  being  tightly  closed,  the 
edges  of  the  skin  wound  are  drawn  into  the  tarsus,  and  become 
adherent  to  it.  The  sutures  may  be  removed  about  the  third  day. 
If  the  first  incision  be  placed  too  far  from  the  margin  of  the  lid, 
there  will  be  no  result,  as  the  traction  upon  the  palpebral  skin  will 
be  too  slight.  If  the  incision  be  placed  too  close  to  the  margin, 
the  traction  may  be  so  great  as  to  interfere  with  the  union  of  the 
skin  and  tarsus.  In  this  operation  the  tarsus  affords  the  fulcrum, 
which  Hotz  thinks  is  wanting  in  other  methods.     The  tarsus  of 


Fig.  247. 


(at  a). 


572  DISEASES    OF    THE   EYE.  [chap,   xviii. 

the  lower  lid  is  sometimes  badly  developed,  and  the  result  of  the 
operation  may  then  be  disappointing. 

Ectropion  or  Eversion  of  the  Eyelid. — Of  this  there  are  three 
kinds  :    (1)  Muscular,  or  Spastic.     (2)  Cicatricial.     (3)  Paralytic. 

Muscular  Ectropion  occurs  only  in  the  lower  eyelid  and  may 
have  its  starting-point  in  oedema  of  the  conjunctiva,  which  averts  the 
edge  of  the  eyelid,  and  this  eversion  becomes  increased  and  encour- 
aged by  spasm  of  the  palpebral  portion  of  the  orbicular  muscle,  so 
that  the  term  palpebral  paraphimosis  might  be  given  to  the  con- 
dition. In  the  recent  stage  it  may  generally  be  remedied  by  suit- 
able conjunctival  measures.  In  chronic  cases  operative  measures 
are  usually  required. 

Muscular  ectropion  is  often  seen  in  old  people,  and  is  then  given 
the  name  of  Senile  Ectropion.  Here  it  is  due  to  atrophy  of  the 
palpebral  portion  of  the  orbicularis  of  the  lower  lid,  and  relaxation 
of  the  skin  of  the  face.  When  these  have  resulted  in  slight  eversion 
of  the  inferior  punctum,  a  flowing  of  tears  is  produced,  causing  some 
excoriation  of  the  skin  and  edge  of  the  lid,  which  then  increase  the 
tendency  to  ectropion.  If  the  condition  be  not  extreme,  with 
secondary  changes  in  the  conjunctiva,  slitting  up  of  the  canaliculus, 
with  the  use  of  any  simple  ointment  for  the  lids,  and  mild  astring- 
ents for  the  conjunctiva,  will  give  much  relief.  In  pronounced  cases, 
a  more  active  treatment  of  the  conjunctiva,  and  the  performance  of 
tarsoraphy,  or  the  application  of  Snellen's  sutures,  or  one  of  the  other 
operations  described  below,  are  demanded. 

The  following  operations  are  amongst  the  best  for  the  correction 
of  muscular  ectropion  : — 

Snellen'' s  Sutures. — A  silk  ligature  is  threaded  at  either  end  with 
a  needle  of  moderate  size  and  curve.  The  point  of  one  of  these 
needles  is  passed  into  the  most  prominent  point  of  the  exposed  and 
everted  conjunctiva,  and  brought  out  through  the  skin  2  cm.  below 
the  edge  of  the  lower  lid.  The  other  needle  is  entered  in  the  same 
way  5  mm.  from  the  first,  and  made  to  take  a  nearly  parallel  course, 
the  points  of  exit  on  the  cheek  being  1  cm.  apart.  Equal  traction 
is  applied  to  each  end  of  the  suture,  while  the  lid  is  assisted  into  its 
place  by  the  finger.  The  suture  is  tied  on  the  cheek,  a  small  roll  of 
sticking-plaster  having  been  inserted  under  it  to  protect  the  skin 
from  being  cut.  Two,  or  even  three,  such  sutures  may  be  required, 
and  they  are  allowed  to  remain  for  several  days. 


CHAr.   xvTTT.]  THE   EYELTDS.  573 

Frcdand  Fcnjus  Mclliod. — Fergus  puiiils  uut  that  the  two-tliirds 
of  the  exposed  eonjuiietival  surface  of  the  lower  eyelid,  from  the 
fornix  towards  the  free  Jiiariiin,  are  usually  eoniparativel}'  healthy, 
the  marginal  third  alone  being  diseased.  He  has  devised  the  follow- 
ing procedure,  which  consists  in  excision  of  the  diseased  tissue.  An 
incision  is  made  through  the  conjunctiva  from  the  inner  to  the  outer 
canthus,  demarcating  its  healthy  from  its  diseased  portion.  With 
forceps  and  scissors  the  conjunctiva  covering  the  healthy  portion 
of  the  eyelid  is  freed  from  the  nnderlying  structures  right  down  to 
the  region  of  the  retro-tarsal  fold.  The  hypertrophied  tissue  is  next 
excised  throughout  its  entire  extent,  so  as  to  restore  as  it  were  the 
original  margin  of  the  lid,  and  finally  the  conjunctiva  is  drawn  up 
and  secured  by  a  few  points  of  suture  to  the  margin.  The  success 
of  the  operation  depends  on  the  thoroughness  with  which  the 
excision  of  the  hypertrophied  tissue  is  effected. 

Kuhnfs  Operation  for  Senile  Ectropion  is  an  admirable  one.  It 
consists  in  splitting  the  lower  eyelid  in  its  central  third,  so  that  the 
conjunctiva  and  tarsus  are  left  in  the  posterior  layer,  while  the 
anterior  layer  contains  the  orbicularis  and  the  skin.  A  triangular 
piece,  the  base  of  which  is  formed  by  the  margin  of  the  lid,  is  then 
excised  from  the  posterior  layer,  and  the  margins  of  the  loss  of  sub- 
stance in  the  latter  are  brought  together  by  three  or  four  points  of 
suture.  Lest  they  should  give  way  too  soon,  it  is  necessary  to  place 
these  sutures  very  securely.  A  puckering  of  the  anterior  layer, 
opposite  the  line  of  sutures  in  the  posterior  layer,  is  produced, 
but  subsequently  disappears,  and  a  suture  which  unites  the  most 
prominent  point  of  the  pucker  with  the  margin  of  the  tarsus  assists 
in  this.  Or,  if  the  lid  be  split,  say,  to  an  extent  twice  as  long  as 
the  base  of  the  triangular  piece  to  be  excised,  the  puckering  can 
be  distributed  at  either  end  of  the  incision.  It  is  by  reason  of  the 
shortening  of  the  posterior  layer  of  the  split  eyelid  that  the  eversion 
is  corrected.  We  frequently  use  this  operation,  and  always  with 
gratifying  results. 

Kenneth  Scott's  Operation. — The  external  canthus  and  the  tissues 
beyond  it  are  thoroughly  divided  by  a  pair  of  strong  scissors.  The 
lower  eyelid,  which  is  usually  the  affected  one,  is  then  seized,  and  its 
margin  stretched  sufficiently  outwards,  parallel  to  the  border  of  the 
other  lid,  so  as  to  restore  the  palpebral  aperture  to  its  proper  appear- 
ance ;   the  portion  of  eyelid  margin  thus  made  to  extend  beyond  the 


574  DISEASES    OF    THE   EYE.  [ch.aj-.  xviir. 


site  of  the  external  canthus  is  removed,  along  with  its  contained  eye- 
lashes, by  slicing  it  with  a  sharp  kuife.  The  upper  and  lower  eyelids 
are  then  brought  together,  so  that  the  original  outer  extremity  of 
the  upper  eyelids  approximates  exactly  to  the  new  extremity  of  the 
lower  eyelid.  They  are  secured  in  this  position  by  passing  a  silver 
wire  suture,  vertically  downwards  through  the  substance  of  the 
upper  lid,  continuing  it  out  through  that  of  the  lower  one,  and  then 
twisting  the  ends  firmly  together.  Two  of  these  retaining  stitches 
may  be  introduced  close  together  if  necessary.  The  edges  of  divided 
skin,  along  with  the  deeper  muscular  tissues,  including  that  part 
which  recently  formed  the  outer  end  of  the  affected  eyelid,  are 
simply  stitched  together  with  a  continuous  fine  silk  suture. 

No  dressing  other  than  a  repeated  dusting  with  some  fine  anti- 
septic powder  need  be  used.  The  silk  stitches  may  be  removed  in 
six  days'  time,  the  silver  ones  being  left  in  for  five  or  six  days  longer. 
Scott  states  there  is  never  any  puckering  apparent  beyond  the  newly 
formed  canthus,  and  the  small  linear  cicatrix  is  lost  amongst  the 
other  lines  often  found  there. 

Cicatricial  Ectropion  is  caused  by  chronic  blepharitis  with 
dermatitis  of  the  skin  of  the  eyelid  (p.  543).  It  is  also  caused  by 
scars  in  the  eyelid  from  caries  of  the  orbit,  or  from  wounds  or  burns, 
which  destroy  the  integument  of  one  or  both  eyelids.  Cicatricial 
ectropion  caused  by  burns  of  the  face  and  eyelids  in  epileptics  or 
children  who  have  fallen  into  the  fire  is  not  uncommon.  The 
burnt  skin  of  the  eyelids  is  replaced  by  a  granulating  surface  ;  and, 
when  cicatrisation  of  this  surface  commences,  the  free  margin  of 
the  upper  lid  is  drawn  up  towards  the  eyebrow,  and  that  of  the 
lower  lid  down  towards  the  cheek,  the  conjunctival  surface  of  the 
eyelids  in  consequence  becoming  everted,  and  the  cornea  exposed, 
as  the  eyelids  cannot  now  be  closed. 

For  the  higher  degrees  of  ectropion  due  to  chronic  blepharitis 
— or,  as  it  is  called.  Blepharitis  Ectropion — in  the  lower  lid,  Kuhnt's 
Operation  consists  in  the  splitting  of  the  eyelid  in  its  whole  extent 
into  two  layers,  an  anterior  (skin-muscle)  and  a  posterior  (tarsus- 
conjunctiva)  and  the  shifting  of  the  layers  on  each  other  so  that  the 
anterior  one  is  elevated  while  the  posterior  one  is  lowered.  It  is 
performed  as  follows  : — 

The  lower  eyelid  is  stretched  in  a  lid-clamp.  An  incision  is  made 
through  the  skin  (Fig.  248)  immediately  below  the  eyelashes.     The 


(■•IfAr.     XVTTT.] 


THE   EYELIDS. 


roots  of  any  eyelashes  wJiicli  m;iy  he  exposed  should  be  removed 
Avithout  injury  to  the  skin.  An  incision  is  n(j\v  made  from  end  to 
end  in  the  intermarginal  portion  of  the  lid  (dotted  line  in  Fig.  248), 
and  as  deep  as  the  inferior  orbital  margin  in  the  temporal  and  nasal 
directions.  The  intermarginal  incision  is  continued  in  the  nasal 
direction  as  far  as  the  anterior  crista  lacrimalis,  with  a  depth  of 
rO  to  1'5  cm.,  care  being  taken  not  to  injure  the  canaliculus.  The 
temporal  extension  of  the  intermarginal  incision  is  made  to  pass 
steeply  upwards  and  outwards,  and  then  rectangularly  outwards 
and  downwards  (compare  Fig.  248).       If  the  anterior  (skin-muscle) 


Fig.  248. 


layer  be  now  tightly  stretched,  the  further  splitting  of  the  lid  below 
the  inferior  orbital  margin  can  easily  be  accomplished,  and  without 
injury  to  the  tarso-orbital  fascia.  (In  Fig.  248  the  punctated  portion 
represents  the  undermined  region.)  At  the  external  canthus  the 
tarso-conjunctival  layer  is  then  divided  as  though  for  a  cantho- 
plastic  operation  (p.  565).  In  order  to  lower  the  posterior  layer, 
from  three  to  five  sutures,  each  with  two  needles,  are  passed  through 
it,  being  entered  between  the  lower  margin  of  the  tarsus  and  the 
conjunctival  fornix  into  the  space  between  the  anterior  and  pos- 
terior layers  of  the  split  lid.  They  are  then  passed  through  the 
anterior  layer  so  that  they  may  appear  through  the  skin  1  cm. 
below  and  concentrically  to  the  orbital  margin.  The  suture  which 
lies   in  the  most  nasal  direction  should  be   placed   about   2   mm. 


r^7fi  DISEASES    OF    THE   EYE.  [CHAr.   xvitt. 

to  tlie  outside  and  below  the  puiietum  lacrimale,  so  that  the  nasal 
half  of  the  posterior  layer  may  be  well  drawn  down.  In  order  to 
raise  the  anterior  layer  at  its  temporal  end,  there  is  removed 
from  the  outer  end  of  the  upper  lid  a  wedge-shaped  piece  of  skin 
and  underlying  tissue  of  1-0  to  1'5  mm.  in  width  at  its  base  {A, 
Fig.  248).  The  margins  of  the  space  that  results  are  drawn  together 
with  two  or  three  sutures  armed  with  two  needles  placed  deeply 
in  the  edge  of  the  wound,  and  a  few  superficial  sutures  are  added, 
in  order  to  draw  the  margins  neatly  together.  To  secure  a  sufficient 
elevation  of  the  nasal  end  of  the  anterior  layer,  especially  for  the 
punctuni  lacrimale,  a  double-armed  suture  is  similarly  passed  through 
the  anterior  layer  4  mm.  below  its  margin  and  opposite  the  middle 
of  the  internal  palpebral  ligament,  and  is  tied  to  the  palpebral 
ligament  close  to  the  lacrimal  crest.  The  anterior  layer  is  now 
very  tense.  Finally,  the  posterior  layer  is  drawn  down  by  aid  of 
the  double-armed  sutures,  which  are  tied  on  the  cheek.  The  sutures 
may  be  removed  in  seven  or  eight  days. 

For  the  relief  of  the  extreme  ectropion  due  to  burns  of  one  or 
both  eyelids,  the  best  method  is  that  of  Wolfe  by  Skm  Trans'planta- 
tion.     It  is  performed  as  follows  : — 

In  the  first  place  the  eyelid — let  it  be  the  upper  eyelid — is  dis- 
sected down  into  its  place  to  the  utmost  limit,  so  that  the  most 
extensive  raw  surface  possible  may  be  obtained.  The  margin  of 
the  lid,  having  been  drawn  over  the  lower  lid,  is  fastened  to  the 
cheek  with  three  points  of  suture.  A  portion  of  skin,  suited  as  re- 
gards shape,  and  about  one-third  larger  (to  allow  for  shrinkage) 
than  the  raw  surface  of  the  eyelid,  is  then  taken  from  the  inside  of 
the  arm,  and  having  been  carefully  freed  of  all  its  subcutaneous  fat 
and  connective  tissue,  is  laid  upon  the  raw  surface,  and  secured 
to  it  by  a  large  number  of  fine  interrupted  sutures  around  the 
margin.  Or,  if  the  margin  of  the  skin  surrounding  the  raw  surface 
be  dissected  up,  the  edge  of  the  graft  can  be  slipped  under  it,  and 
secured  in  its  place  by  this  means.  It  is  essential  in  the  case  of 
grafts  on  the  lower  lid,  to  prevent  them  from  becoming  infiltrated 
and  sodden  with  the  lacrimal  or  conjunctival  secretion,  and  in  order 
to  keep  the  graft  dry  we  are  in  the  habit  of  filling  up  the  hollow 
at  the  side  of  the  nose  and  the  inner  canthus  with  a  liberal  supply 
of  boric  acid  pow^der.  A  non-irritating  dry  dressing,  or  an  oint- 
ment dressing,  is  applied,  and  the  graft  usually  heals  on.     In  most 


CHAT.  XVIII.]  THE   EYELIDS.  577 

cases  the  most  superficial  layer  of  the  epidermis  peels  off  after  a  few- 
days.  This  method  of  grafting  was  introduced  by  Wolfe  and  Lefort, 
and  it  may  be  employed  in  all  these  cases  with  most  satisfactory 
results. 

It  is  important  to  preserve  and  utilise  any  part  of  the  skin  of 
the  eyelid  which  remains,  especially  its  ciliary  border  with  the  eye- 
lashes. The  thorough  cleaning  of  the  flap  from  its  subcutaneous 
fat  and  connective  tissue  is  also  important,  as  otherwise  an  unsightly 
and  lumpy  effect  is  produced  when  the  flap  has  healed  on.  While 
this  cleaning  is  being  done,  the  flap  should  lie  on  a  warm  sterilised 
porcelain  plate.  The  flap  should  not  be  applied  to  the  raw  surface 
until  all  oozing  of  blood  from  the  latter  has  ceased. 

The  transplantation  of  a  flap  with  pedicle  from  the  forehead, 
temple,  or  cheek  is  also  used  to  repair  an  eyelid  ;  but,  owing  to  the 
thickness  of  the  integument,  the  result  is  cosmetically  less  satisfac- 
tory than  that  given  by  a  graft  fi'om  the  arm,  w^hile  the  tendency 
to  shrink  is  quite  as  great. 

Some  prefer  Thiersch  grafts  to  dermic  grafts,  and  state  they  are 
more  easily  applied  to  the  raw  surface,  and  do  not  differ  in  colour 
from  the  surrounding  skin  when  healing  is  completed.  It  is  desirable 
to  obtain  one  continuous  graft  of  the  whole  size  of  the  w^ounded 
surface. 

Paralytic  Ectropion  is  due  to  lo«s  of  power  in  the  orbicular 
muscle  in  cases  of  paralysis  of  the  seventh  nerve.  It  occurs  in 
the  lower  lid  only,  which  falls  outw^ards  by  its  own  weight  when 
not  kept  in  contact  with  the  eyeball  by  the  tone  of  the  muscle. 
The  condition  is  remedied  by  a  tarsoraphy  (p.  561)  when  all  hope 
of  recovery  of  the  paralysed  nerve  has  to  be  abandoned. 

*  Ankyloblepharon  {dyKvkq,  a  string ;  (^\i(fiapov,  an  eyelid)  is 
a  uniting  of  the  upper  and  lower  eyelids  along  their  margins.  It 
may  be  partial  or  complete,  and  often  goes  with  symblepharon. 
Like  the  latter,  it  is  usually  caused  by  burns  and  ulcers. 

The  condition  can  only  be  relieved  by  operation,  of  w^hich  the 
result  is  often  unsatisfactory,  owing  to  the  difficulty  of  preventing 
re-union  taking  place  at  the  canthi.  To  avert  this,  it  is  always 
necessary  to  cover  the  wounded  surface  with  conjunctiva  or  skin. 

Injuries  of  the  Eyelids. — All  kinds  of  injuries  of  the  eyelids  (con- 
tusions, incisions,  burns,  etc.)  are  common. 

In  consequence  of  the  looseness  of  the  integument,  oedema  and 
37 


578  DISEASES   OF    I'BE   EYE.  [chap,  xviit. 

ecchymosis,  one  or  both,  are  often  seen  in  a  marked  degree  as  the 
result  even  of  slight  injuries. 

Owing  to  the  direction  of  the  fibres  of  the  orbicularis,  an  incised 
wound  of  the  eyelid,  if  in  the  vertical  direction,  will  gape,  while  a 
similar  w^ound  in  the  horizontal  direction  will  not  do  so.  Hence  the 
scar  left  after  the  former  wound  is  apt  to  be  very  visible,  but  that 
after  the  latter  may  be  almost  imperceptible.  If  the  eyelid  be 
divided  vertically  in  its  entire  thickness,  unless  union  by  first  inten- 
tion can  be  obtained,  a  deep  furrow  is  left  in  the  eyelid,  and,  perhaps, 
at  its  margin  an  unsightly  coloboma. 

The  result  of  burns  of  the  eyelids  has  been  treated  of  at  p.  574. 
Emphysema  of  the  eyelids  is  sometimes  seen  after  a  blow  on  the 
eye,  and  is  a  sign  of  fracture  of  the  orbit  complicated  with  a 
communication  between  the  subcutaneous  connective  tissue  of  the 
eyelids  and  the  nose,  the  ethmoid  sinus,  the  frontal  sinus,  or  the 
antrum  of  Highmore.  An  emphysematous  lid  is  swollen,  soft,  and 
crepitating  to  the  touch. 

Ecchymosis  of  the  lower  lid,  usually  with  ecchymosis  of  the  lower 
portion  of  the  conjunctiva,  after  falls  or  blows  on  the  head,  is  a 
sign  of  fracture  of  the  base  of  the  skull,  the  blood  making  its  way 
along  the  floor  of  the  orbit. 

Simple  ecchymosis  of  the  eyelids  from  blows,  commonly  known 
as  '  black  eye,'  never  gives  rise  to  further  complication.  It  requires 
some  fourteen  days  or  more,  according  to  the  quantity  of  blood 
extravasated,  before  the  eye  recovers  its  normal  appearance. 

Treatment. — Injuries  of  the  eyelids,  of  whatever  kind,  are  of 
course  treated  upon  general  surgical  principles.  Incised  wounds 
should  be  carefully  and  neatly  drawn  together  with  sutures  as  soon 
after  the  injur}^  as  possible,  and  with  antiseptic  precautions. 
Emphysema  may  be  assisted  in  its  absorption  by  the  application 
of  a  rather  tight  bandage,  and  directions  should  be  given  to  the 
patient  to  blow  his  nose  as  gently  as  possible,  so  as  to  avoid  recur- 
rence of  the  condition. 

*  Epicanthus  is  a  congenital  deformity,  generally  binocular,  associ- 
ated in  the  most  pronounced  cases,  with  paralysis  of  the  levator 
palpebrae  (ptosis),  and  usually  also  of  the  rectus  superior,  with  a 
narrow  palpebral  fissure.  It  consists  of  a  fold  of  integument  at 
the  inner  canthus  which  conceals  the  caruncle  from  view  (Fig.  201), 
and    gives    the    appearance     of     great     breadth     to     the     bridge 


CHAP,  xviii.]  THE   EYELIDS.  579 


of  the  nose.  In  young  children  epicanthus  may  exist  without 
ptosis,  and  in  many  of  these  cases  the  condition  disappears  with 
the  growth  of  the  bridge  of  the  nose.  If  necessary  the  deformity 
can  be  somewhat  diminished  by  the  removal  of  an  oval  piece  of 
skin  from  the  l)ridge  of  the  nose,  its  long  axis  being  vertical  and  its 
width  varying  according  to  the  effect  retjuired.  When  the  margins 
of  the  wound  are  brought  togethei',  the  abnormal  epicanthal 
folds  become  flattened  out. 

*  Congenital  Coloboma  of  the  upper  lid— sometimes  associated 
with  a  dermoid  cyst  of  the  limbus  of  the  cornea  corresponding  with 
the  cleft  in  the  lid — and  even  congenital  absence  of  the  eyelids,  have 
been  occasionallv  observed. 


CHAPTER    XIX. 

DISEASE   OF   THE  LACRIMAL  ^    APPARATUS. 

Overflowing  of  tears  from  the  eye  may  be  due  either  to  hyper- 
secretion or  defective  excretion.  In  the  former  case  the  lacrimation 
is  more  or  less  of  a  temporary  phenomenon,  is  independent  of  disease 
of  the  lacrimal  apparatus,  and  is  occasioned  by  reflex  irritation 
arising  in  the  eye  from  such  causes  as  diseases  of  the  cornea  or  uveal 
tract,  foreign  bodies,  misplaced  cilia,  etc.,  or  the  hypersecretion  may 
be  of  central  origin,  emotional  or  hysterical.  On  the  other  hand, 
a  persistent  oyerflow  of  tears,  in  the  absence  of  any  source  of  irri- 
tation, is  with  rare  exceptions  caused  by  obstruction  or  inefficient 
action  of  the  channels  whereby  the  tears  are  excreted,  and  is  usually 
termed  epiphora  (eVtc^opa  I'SaKpuoj,  a  flow  of  tears). 

The  commonest  diseases  of  the  lacrimal  apparatus  are  those 
which  cause  epiphora,  and  these  will  first  be  described. 

Malposition  of  the  Punctum  Lacrimale.- — The  punctum  in  the 
lower  lid  is  more  efficient  for  carrying  off  tears,  than  that  in  the 
upper  lid,  and  a  derangement  of  the  lowec  punctum  alone  is  sufficient 
to  give  rise  to  epiphora.  Normally  the  punctum  lies  against  the 
eyeball  and  cannot  be  seen,  unless  the  observer  draws  the  inner  end 
of  the  lid  away  from  the  eye.  Inversion  of  the  punctum  accom- 
panies entropion  of  the  lower  eyelid,  while  eversion  of  it  is  present 
with  ectropion  of  the  lid.  A  slight  eversion,  quite  sufficient  to 
cause  epiphora,  may  exist  without  any  marked  ectropion  of  the  lid, 
and  it  is  these  cases  which  more  properly  belong  to  this  chapter. 
They  are  the  result  generally  of  some  chronic,  although  it  may  be 
slight,  skin  affection  of  the  lower  lid,  which  draws  the  inner  end  of 
the  latter  slightly  away  from  the  eyeball. 

1  Lacrima,  a  tear. 

2  In  this  chapter,  and  elsewhere  in  the  book,  the  terms  punctum  lacri- 
male  and  canaHculus  refer  to  the  inferior  passage,  unless  it  be  otherwise 
expressly  stated. 

580 


CHAP.  XIX.]  THE    LACRIMAL    APPARATUS.  5H1 


! 


Inversion  of  the  punctum  can  only  be  relieved  l)y  an 
entropion  operation  on  the  eyelid. 

Stenosis,  and  Complete  Occlusion  of  the  Punctum 
Lacrimale. — Either  of  these  conditions  may  result  from  |!| 

conjunctivitis,  oi-  from  marginal  blepharitis,  although 
they  may  uot  appear  for  a  length  of  time  after  those 
affections  have  passed  away,  and  the  original  affection 
may  have  been  so  slight  as  to  have  escaped  the  observa- 
tion of  the  patient.  In  stenosis  the  size  of  the  punctum 
may  become  so  extremely  minute,  that  even  the  normal 
flow  of  tears  is  too  copious  to  pass  through  it.  Complete  oc- 
clusion is  probably  only  a  more  advanced  stage  of  stenosis. 

The  Treatment,  in  cases  of  eversion  of  the  punctum 
without  marked  ectropion  of  the  lid,  of  stenosis,  and  of 
complete  occlusion,  is  similar,  namely,  the  opening  up 
of  the  punctum,  and  its  conversion  into  a  slit.  This 
is  done  with  a  Weber's  knife  (Fig.  2-19),  the  probe- 
point  of  which  is  passed  into  the  punctum  in  cases  of 
eversion,  forced  into  the  small  opening  in  cases  of 
stenosis,  or  forced  through  the  usually  thin  covering  of 
the  punctum  in  cases  of  occlusion.  In  doing  this  the 
lower  lid  should  be  stretched  rather  tightly  by  a  finger 
of  the  surgeon's  left  hand  placed  near  the  external 
canthus.  The  probe-point  having  entered  the  punctum, 
the  edge  of  the  knife  is  turned  slightly  towards  the 
eyeball,  and  the  instrument  is  pushed  on  into  the 
canaliculus,  until  2  mm.  of  the  latter  has  been  opened 
up,  and  is  then  withdrawn.  If  the  edge  of  the  knife 
be  directed  outwards  in  this  proceeding,  the  incision 
comes  to  lie  on  the  outer  edge  of  the  intermarginal 
portion  of  the  lid,  and  not  in  contact  with  the  eyeball ; 
consequently  the  result  is  unsatisfactory,  for  the  tears 
are  not  carried  away,  and  the  disfigurement  produced  Fig.  2-4U. 
may  be  considerable.  A  slitting  up  of  the  whole,  or 
the  greater  part,  of  the  canaliculus  in  these  cases  is  unnecessary, 
and  interferes  with  the  physiological  action  of  the  tear  passage. 
For  two  or  three  days  after  the  little  operation,  it  is  necessary 
to  pass  a  probe  along  the  portion  of  the  canaliculus  which  has 
been  slit  uj),  to  prevent  union  taking  place. 


582  DISEASES   OF    THE   EYE.  [chap.  xix. 

When,  as  sometimes  happens  in  old  people,  and  occasionally 
even  in  the  middle-aged,  from  relaxation  of  the  orbicularis,  the 
inner  end  only  of  the  under  lid  is  everted,  the  excision  of  a  small 
flap  of  conjunctiva  somewhat  after  the  manner  of  Fergus  (p.  573) 
will  restore  the  punctum  to  its  normal  position. 

Obstruction  of  the  Canaliculus. — The  canaliculus  may  be  di- 
minished in  its  calibre,  or  entirely  closed,  by  contraction,  which  is 
the  result  of  inflammation  that  has  extended  to  it  from  the  con- 
junctival sac.  It  is  not  possible  to  diagnose  the  presence  of  either 
of  these  conditions,  which  may  be  associated  with  stenosis  or  oc- 
clusion of  the  punctum  lacrimale,  except  by  the  introduction  of  a 
very  hue  probe  into  the  canaliculus.  The  passage  may  also  be 
obstructed  by  an  eyelash,  a  chalky  deposit,  or  a  mass  of  streptothrix. 

The  diagnosis  of  streptothrix  in  the  inferior  canaliculus — it 
rarely  affects  the  upper  canaliculus — is  made  by  the  following  signs 
and  symptoms  : — Lacrimation  ;  the  presence  of  a  creamy-yellow 
discharge  at  the  inner  canthus,  without  dacryocystitis  ;  congestion 
of  the  caruncle  and  neighbouring  parts  of  the  conjunctiva.  On 
everting  the  inner  end  of  the  lower  lid,  the  region  corresponding  with 
the  canaliculus  is  seen  to  be  rounded  and  swollen  on  its  conjunctival 
aspect.  The  lacrimal  punctum  is  enlarged,  stands  out  from  the 
eyeball  when  the  patient  looks  up,  and  is  filled  w^ith  creamy  exuda- 
tion. On  palpation,  a  hard  cylindrical  mass  can  be  felt  in  the 
canaliculus.  At  a  later  stage,  severe  purulent  inflammation  of  the 
canaliculus  comes  on,  with  marked  swelling  of  the  eyelid  in  the 
neighbourhood,  and  pain.  The  greenish-yellow  dacryolith  con- 
tained in  the  canaliculus  usually  consists  of  a  streptothrix,  which 
some  regard  as  actinomyces. 

Treatment. — Where  there  is  merely  diminution  in  the  calibre  of 
the  passage,  the  introduction  of  a  conical  stylet  (Fig,  249)  or  of 
probes,  increasing  in  size,  is  frequently  sufficient  to  effect  a  cure. 
If  dilatation  fail,  recourse  must  be  had  to  slitting  up  the  canaliculus  ; 
but,  if  it  can  possibly  be  avoided — that  is,  if  a  less  extended  opening 
will  answer — the  passage  should  not  be  slit  up  in  its  entire  length. 
At  least  3  mm.  of  its  median  end  ought  to  be  left  intact,  as  other- 
wise regurgitation  of  tears  from  the  lacrimal  sac  is  liable  to  trouble 
the  jDatient  ever  afterwards.  If  the  canaliculus  be  completely  closed 
by  adhesions,  so  that  a  fine  probe  cannot  be  pushed  through  it, 
it  becomes  necessary  to  rip  it  up  with  the  point  of  any  small  knife, 


CHAP.   XIX.]  THE    LACRIMAL    APPAHATUS.  583 

following  the  known  course  of  the  passage  from  the  outside.  If  the 
canaliculus  be  closed  as  far  as  the  opening  into  the  sac,  or  if  only 
at  that  point,  the  obstruction  must  be  pierced  with  the  point  of  a 
fine  knife.  A  difficulty  in  all  these  cases  is  to  keep  the  passage 
patent  when  once  formed.  A  plan  which  affords  tolerable  certainty 
of  this  is  the  frequent  passage  of  probes  into  the  sac  until  the  ten- 
dency to  closure  seems  to  have  ceased  ;  but  even  under  favourable 
conditions  recurrences  of  the  closure  are  apt  to  occur. 

Streptothrix  in  the  lower  canaliculus  is  readily  cured  by  slitting 
up  the  passage  and  evacuating  its  contents,  or  by  expressing  the 
contents  when  possible  without  dividing  the  canaliculus,  and 
syringing  out  with  oxycanate  of  mercury. 

Stricture  of  the  Nasal  Duct  is  usually  the  result  of  simple  acute 
swelling  of  its  mucous  membrane  in  a  catarrhal  attack,  which  has 
originated  in  the  nasal  mucous  membrane.  Or,  it  is  caused  by 
membranous  or  cicatricial  contraction  of  the  mucous  membrane 
resulting  from  long-continued  chronic  catarrh.  It  also  occurs  in 
consequence  of  disease  of  the  bones  of  the  nose — e.g.  in  syphilis, 
acquired  or  congenital,  and  from  blows  Avhich  fracture  the  bridge 
of  the  nose. 

Treatment. — It  is  desirable  to  commence  the  treatment  by 
syringing  the  nasal  duct,  the  fine  point  of  an  Anel's  syringe  being 
introduced  into  the  punctum  lacrimale  and  canaliculus.  It  may  be 
necessary  to  dilate  the  punctum  with  the  stylet  (Fig.  249)  before  the 
syringe  can  be  introduced.  In  some  cases,  where  the  obstruction 
is  merely  a  plug  of  mucus,  the  syringe  may  at  once  effect  a  cure. 
Stricture  due  to  acute  inflammatory  swelling  of  the  mucous  mem- 
brane should  be  treated  by  the  injection  of  weak  alum  or  other 
astringent  solutions  into  the  lacrimal  sac,  or  through  the  nasal  duct, 
by  means  of  an  Anel's  syringe ;  and  attention  should  be  paid  to 
the  condition  of  the  nasal  mucous  membrane.  Probing  here  should 
not  be  attempted,  lest  it  injure  the  delicate  swollen  mucous 
membrane  of  the  duct. 

Membranous  or  cicatricial  strictures  are  best  treated  by  means 
of  probes  in  the  manner  proposed  by  Sir  William  Bowman.  As 
the  process  is  a  painful  one,  cocaine  should  first  be  injected  into  the 
passages  with  the  syringe.  Smearing  the  probe  with  some  aseptic 
oil  or  simple  ointment  also  facilitates  matters.  Probes  as  large 
as  numbers  3  or  4  can  Ije  introduced  into  the  canaliculus  if  the 


584 


DISEASES    OF    THE   EYE. 


[chap.    XIX. 


punctum  be  first  dilated.  Should  there  be  any  difficulty,  or  if 
larger  sizes  are  needed,  the  inferior  canaliculus  is  slit  up  to  a  slight 
extent  so  as  to  admit  the  point  of  one  of  Bowman's  smallest  probes, 
which  has  been  given  a  curve  to  suit  that  of  the  nasal  duct.  With 
a  finger  of  the  left  hand  (Fig.  250),  if  it  be  the  patient's  left  eye, 
the  surgeon  stretches  the  lower  lid,  and,  entering  the  probe  with 
the  right  hand  into  the  canaliculus,  he  pushes  it  gently  along 
its  floor  until  the  point  reaches  the  lacrimal  bone  (Fig.  250,  position 
No.  1).  The  point  being  kept  pressed  against  this  bone,  the  direction 
of  the  probe  is  now  altered,  by  carrying  its  free  end  upwards  to- 


FiG.  250. 


wards  the  bridge  of  the  nose,  until  the  point  w^hich  is  in  the  lacrimal 
sac  is  directed  towards,  or  aimed  at,  the  sulcus  between  the  ala 
of  the  nose  and  the  cheek.  The  probe  in  this  position  (Fig.  250, 
position  No.  2)  corresponds  with  the  prolonged  axis  of  the  nasal  duct, 
down  which  it  is  pushed  slowly  and  with  gentle  pressure.  If  it  be 
the  right  eye,  the  surgeon  reverses  his  hands,  or  operates  from 
behind  the  patient.  Any  obstacles  met  with  are  overcome,  if 
possible,  by  an  increase  of  the  pressure  ;  but  if,  at  any  part  of  the 
passage,  much  difficulty  be  encountered,  rather  than  that  any 
violence   be   used,   further   manipulation   should   be   postponed   to 


CHAP.  XIX. 1  THE   LACRIMAL   APPARATUS.  585 


another  day  ;  and  it  will  often  be  found  that  at  the  second  or  third 
visit  the  probe  is  passed  with  comparative  ease.  Thicker  Bowman's 
probes  are  gradually  introduced  at  successive  sittings,  until  the 
largest  size  has  been  reached. 

The  most  common  seats  for  membranous  oi-  cicatricial  stricture 
of  the  nasal  duct  are  at  the  upper  end,  where  it  enters  the  sac,  and 
where  it  is  at  its  narrowest ;  and  at  the  lower  end,  where  it  is  mainly 
exposed  to  catarrhal  processes  spreading  from  the  nostril. 

Weber's  probes  are  conical,  and  of  very  large  calibre  at  their 
thickest  part.  The  objection  to  such  large  conical  probes  is  that 
when  passed  into  the  nasal  duct,  their  thickest  part,  w^hich  is  3  to  4 
mm.  in  diameter,  corresponds  with  the  upper  end  of  the  duct,  which 
is  its  narrowest  part,  being  only  3  mm.  in  diameter.  Consequently, 
the  probe  becomes  more  or  less  impacted  at  this  place  at  each  opera- 
tion, and  this  impaction,  from  injury  of  the  mucous  membrane 
and  periosteum,  is  liable  ultimately  to  give  rise  there  to  hypertrophy 
of  the  periosteum,  and  finally  to  stricture  ;  so  that,  while  the  im- 
mediate effect  of  their  use  is  perhaps  brilliant,  the  ultimate  result 
is  often  the  reverse.  When  used  by  the  inferior  canaliculus,  their 
size  makes  it  necessary  to  slit  that  passage  in  its  entire  length,  and 
the  entrance  of  the  passage  into  the  sac  must  be  enormously  dilated 
by  so  large  an  instrument,  both  of  w^hich  circumstances  are  most 
undesirable.  The  same  objection  applies  to  the  large  probes 
introduced  by  other  surgeons.  Syringing  the  nasal  duct  should  not 
be  performed  immediately  after  passing  a  probe,  lest  cellulitis  be 
set  up. 

To  prevent  closure  of  the  duct  when  once  made  free,  silver  or 
leaden  styles  can  be  left  in  situ,  the  upper  end  being  curved  so  as 
to  lie  out  on  the  cheek.  The  style  is  at  first  removed  daily,  and 
the  duct  syringed,  until  any  existing  inflammation  and  discharge 
have  almost  ceased.  The  intervals  are  then  increased ;  and  as 
soon  as  practicable  the  patient  is  taught  to  remove  the  style  and 
to  replace  it  himself.  When  he  is  able  to  do  this  easily,  he  is 
directed  to  leave  the  style  out  foi  some  hours  each  day,  and 
finally  to  wear  it  only  at  night. 

Very  obstinate  membranous  strictures  can  sometimes  be  freed 
by  electrolysis. 

The  cases  of  stricture  which  are  the  most  favourable  for  cure 
are  those  due  to  infiannnatory  swelling  of  the  mucous   membrane, 


586  DISEASES    OF    THE   EYE.  [chap.  xix. 

and  next  in  order  come  those  caused  by  membranous  or  cicatricial 
contraction,  while  strictures  due  to  bony  obstructions  are  incurable. 

Now  and  then  cases  of  persistent  lacrimation  will  be  met  with, 
in  which  the  nasal  duct  and  the  rest  of  the  lacrimal  apparatus  seem 
to  be  in  perfect  order.  These  cases  are  often  due  to  a  catarrhal 
affection  of  the  nasal  mucous  membrane,  slightly  involving  the  very 
lowest  extremity  of  the  nasal  duct.  Applications  directed  towards 
relief  of  the  nasal  affection  are  here  indicated. 

Blennorrhoea  of  the  Lacrimal  Sac,  or  Chronic  Dacryocystitis,  is 
commonly  caused,  in  the  first  instance,  by  stricture  of  the  nasal 
duct.  In  consequence  of  this  stricture  the  tears  and  the  normal 
mucous  secretion  of  the  lining  membrane  of  the  sac  are  retained, 
and  offer  favourable  conditions  for  the  growth  of  micro-organisms, 
such  as  the  pneumococcus,  which  is  the  one  usually  present,  or 
more  rarely  an  influenza-like  bacillus  or  the  pneumo-bacillus. 

But  cases  of  lacrimal  blennorrhoea  are  seen  in  which  no  stricture 
of  the  nasal  duct  is  found.  In  many  of  these  cases  there  has  been 
a  temporary  stricture,  due  to  catarrhal  swelling  of  the  lining  mem- 
brane of  the  duct,  which  has  subsided  without  treatment,  and  the 
duct  has  again  become  free,  while  the  lacrimal  blennorrhoea,  to  which 
the  stricture  gave  rise,  continues.  It  is  probable,  however,  that 
lacrimal  blennorrhoea  may  occasionally  come  on  where  there  has 
never  been  a  stricture  of  the  nasal  duct,  and  merely  as  an  extension 
of  catarrh  from  the  nostrils,  especially  in  cases  of  ozsena,  or  as  an 
extension  of  catarrh  from  the  conjunctiva. 

Tubercle  is  occasionally  the  cause  of  dacryocystitis,  but  it  is 
not  possible  to  make  a  clinical  diagnosis  between  these  and  the 
more  common  cases,  if  the  mucous  membrane  of  the  lacrimal  sac 
alone  be  diseased.  But  these  cases  are  very  prone  to  be  attended 
with  the  formation  of  a  fistula,  lined  by  granulations  which  often 
extend  into,  and  undermine,  the  surrounding  skin.  In  many,  but 
not  in  all  cases,  the  tubercular  infection  of  the  sac  extends  from  the 
nostril,  or  from  the  conjunctiva,  one  or  other  of  which  is  the  primary 
seat  of  the  disease.  The  sac  itself  may  be  the  primary  seat  of  the 
tuberculosis,  with  quite  healthy  nasal  and  ocular  mucous  membrane. 

Sijmpoms. — The  patients  as  a  rule  complain  merely  of  lacrima- 
tion. Some,  more  observant  of  themselves,  may  have  noticed  a 
swelling,  known  as  a  lacrimal  tumour  or  mucocele,  in  the  region 
of  the  lacrimal  sac;    and  also  that  the  conjunctival  sac,  especially 


CHAP.   XIX.]  THE   LACRIMAL    Al'PARATUS.  587 

when  the  swelling  is  pressed  upon,  becomes  now  and  then  more  or 
less  filled  with  a  somewhat  viscid  and  opaque  discharge,  which 
obscures  the  sight  until  wiped  away.  Occasionally  there  is  no 
lacrimal  tumour,  for  the  contents  of  the  sac  may  not  be  copious 
enough  to  distend  it  markedly. 

In  order  to  ascertain  in  each  case  of  epiphora  whether  lacrimal 
blennorrhoea  be  present,  the  surgeon  presses  with  his  finger  over 
the  lacrimal  sac,  when,  if  there  be  blennorrhoea,  the  discharge  will 
be  evacuated  through  the  puncta  into  the  conjunctival  sac.  But 
occasionally,  where  there  is  a  deeply  situated  sac,  owing  to  a  pro- 
minent anterior  lacrimal  crest,  although  dacryocystitis  is  present, 
it  may  not  be  possible  to  express  any  discharge  from  the  sac.  Or, 
in  those  cases  in  which  there  is  no  longer  a  stricture  of  the  nasal 
duct,  the  discharge  may  pass  downwards  into  the  nose,  and  the 
patient  will  feel  it  in  his  nostril,  out  of  which  he  can  blow  it. 

Conjunctivitis  must  sometimes  be  regarded,  not  as  the  cause, 
but  rather  as  the  effect  of  a  lacrimal  blennorrhoea,  by  reason  of 
infection  from  the  lacrimal  sac.  Blepharitis,  too,  is  seen  as  a 
further  result  of  infection  from  the  discharge  in  old-standing  cases. 
The  most  serious  complication,  or  consequence,  of  chronic 
dacryocystitis  is  the  serpiginous  ulcer  of  the  cornea,  caused  through 
infection  by  the  pneumococcus  (p.  124). 

Treatment. — It  is  important,  in  the  first  place,  to  ascertain 
whether  there  be  a  stricture  of  the  nasal  duct,  and  lor  this  purpose 
water  should  be  injected  by  means  of  an  Anel's  syringe  through  the 
canaliculus  into  the  duct.  If  the  fluid  make  its  way  freely  into 
the  nose  or  pharynx,  it  may  be  taken  for  granted  that  the  nasal  duct 
is  not  obstructed  ;  but  if,  instead  of  passing  through — or  only  under 
high  pressure — it  distend  the  lacrimal  tumour  to  a  greater  size,  a 
stricture  may  be  assumed.  If  stricture  of  the  nasal  duct  be  present, 
it  should  be  relieved,  if  this  can  be  done,  by  a  few  probings  ;  excessive 
probing  only  aggravates  the  condition  of  the  sac.  Should  there  be 
no  stricture,  and  also  before  and  after  any  existing  stricture  has 
been  relieved,  the  treatment  consists  in  the  very  frequent  pressing 
out  of  the  contents  of  the  sac  by  the  patient,  so  that  no  distension 
of  it  may  occur  ;  and  in  doing  this  he  should  endeavour  to  cause  the 
discharge  to  pass  down  the  nose  rather  than  into  the  eye.  Frequent 
deep  massage  of  the  sac,  which  the  patient  can  be  taught  to  perform, 
is  useful.     Injections  into  the  sac  to  relieve  the  catarrh  should  be 


588  DISEASES    OF    THE   EYE.  [chap.  xix. 

made  daily  by  the  surgeon.  Peroxide  of  hydrogen  and  protargol, 
in  a  15  or  20  per  cent,  solution,  are  good  applications  for  introduction 
into  the  lacrimal  sac.  The  latter  should  first  be  washed  out  with  a 
physiological  salt  solution.  Other  fluids  which  have  been  recom- 
mended are  Sol.  Argyrol  25  per  cent.,  Sol.  Hydrarg.  oxycyanat.  2 
per  cent.,  Sol.  Potas.  perman.  1  in  2500,  and  tincture  of  iodine. 
When  using  the  last,  or  indeed  when  strong  solutions  of  any  kind 
are  employed,  the  eye  should  be  protected  by  a  small  pledget  of 
absorbent  cotton. 

Any  conjunctivitis  or  abnormal  condition  of  the  nasal  mucous 
membrane  should  be  treated.  But  there  are  many  cases  in  which 
nothing  short  of  extirpation  of  the  lacrimal  sac  will  bring  about  a 
radical  cure  of  this  troublesome,  and  even  serious,  complaint. 
Indeed,  for  chronic  cases  this  operation  is  now  commonly  recom- 
mended at  the  first  consultation,  in  view  of  the  disappointing  results 
obtained  from  other  methods. 

Extirpation  of  the  lacrimal  sac. — Prior  to  the  operation,  the 
contents  of  the  sac  should  be  expressed,  and  its  cavity  washed 
out  with  a  sterilised  salt  solution. 

The  patient  should  be  deeply  anoesthetised,  or  an  effectual  local 
anaesthesia  may  be  obtained  as  follows  :^About  fifteen  minutes 
before  the  operation  a  few  drops  of  the  following  solution  are  in- 
jected subcutaneously  in  three  or  four  places  :  1  c.cm.  of  a  1  per 
cent,  solution  of  cocaine,  to  which  is  added  3  minims  of  a  1  in  1000 
solution  of  adrenalin.  By  this  means,  too,  the  haemorrhage,  which 
is  usually  troublesome,  is  reduced  to  a  minimum.  As  a  result  of 
the  injection  slight  oedema  of  the  region  may  be  seen  a  few  days 
after  the  operation. 

The  two  important  guides  which  define  the  position  of  the 
lacrimal  sac  are  the  crest  of  the  lacrimal  bone  and  the  tendo  oculi. 

The  skin  having  been  painted  with  tincture  of  iodine,  an  incision 
down  to  the  bone  and  about  2*5  cm.  in  length  is  made  over  the 
anterior  lacrimal  crest.  It  begins  about  4  mm.  above  the  internal 
palpebral  ligament,  and  ends  about  5  mm.  below  the  commence- 
ment of  the  bony  lacrimal  duct.  As  a  rule  the  palpebral  ligament 
is  not  divided  by  this  incision,  and  has  now  to  be  separated  with 
the  scissors  close  to  its  insertion.  Some  surgeons  consider  it  un- 
necessary and  undesirable  to  divide  the  palpebral  ligament,  because 
it  is  likely  to  lead  to  some  disfigurement,  no  matter  how  carefullv 


ruw.   XIX.] 


THE    LACRIMAL    APPARATUS. 


589 


the  sutures  may  be  upplietl,  but  this  is  not  our  experience.  Miiller's 
specuhini  is  then  inserted  to  draw  aside  the  Hps  of  the  wound, 
and  Axenfeld's  specuhnn  is  inserted  from  the  nasal  side  into  the 
upper  and  lower  angles  of  the  wound  as  deep  as  the  periosteum, 
to  check  the  ti'oubk^sonie  hicmorrlia^e  which  proceeds  mainly  from 
those  angles  (Fig.  251).  If  there  be  bleeding  from  the  small  arteries, 
they  are,  if  possible,  seized  and  twisted,  while  general  oozing  of 
blood  is  moderated  l)y  means  of  compresses  soaked  in  solution  of 
adrenalin  with  cocaine  or  hydrogen  peroxide.  The  fibrous  capsule 
of  the   sac  is  carefully  incised  along  the  crest,  care   being  taken 


Fig.  251. 

that  the  sac  itself  is  not  opened.  The  anterior  wall  of  the  sac, 
greyish  blue  and  shining,  then  becomes  exposed  in  the  cavity.  To 
remove  the  sac  the  surgeon  separates  its  inner  wall  from  the  perios- 
teum with  the  closed  blunt  ends  of  the  scissors,  or  with  a  small 
elevator ;  then  the  fundus  of  the  sac,  along  with  the  strong  fibrous 
capsule  which  is  here  adherent  to  it,  is  drawn  forwards,  and  with 
a  few  strokes  of  the  scissors  is  separated  from  its  bed,  and  the  scissors 
are  passed  behind  the  sac  from  above  and  the  posterior  wall  similarly 
separated.  The  fundus  of  the  sac  is  then  drawn  inwards  and  for- 
wards, and  the  outer  and  what  remains  attached  of  the  anterior 
surface  are  made  free.  Finally,  the  sac  is  cut  off  close  to  the  bony 
canal,  and,  if  there  be  no  impervious  stricture  present,  the  mucous 


590  DISEASES   OF    THE    EYE.  [chap,  xix. 

iiieiiibraiie  of  the  duct  is  curetted  with  a  suitable  sharp  spoon,  or 
a  fine  olive-sliaped  electro-cautery  is  applied  to  it.  The  wound  is 
closed  by  two  or  three  deeply  placed  sutures,  special  care  being 
taken  to  secure  the  palpebral  ligament  to  its  insertion.  An  aseptic 
dressing,  with  graduated  pressure,  should  be  applied  to  keep  the 
walls  of  the  cavity  in  contact. 

Should  the  sac  be  o^^ened  during  the  operation,  its  total  extir- 
pation will  be  rendered  much  more  difficult ; 
Ej '  and  if  any  portion  of  the  sac  be  left  behind, 
the  object  of  the  operation  is  likely  to  be  frus- 
trated by  a  return  of  suppuration.  If  the  sac 
be  not  excised  in  its  entirety,  the  suspicious 
places  must  be  destroyed  by  curetting.  Where 
there  is  a  fistula  of  the  sac,  or  where  there  has 
been  phlegmonous  dacryocystitis,  or  where 
there  has  been  excessive  probing  of  the  nasal 
duct,    the    operation    is   rendered    difficult   by  jlji 

reason  of  adhesions.  [k 

The  wound  heals  rapidly  by  first  intention,  |!s| 

leaving  a  fine  cicatrix  which  causes  practically  l|< 

no  disfigurement.  P 

Fig.  252.         Another  method,  and  one  which  we  prefer,  j  { 

is  to  dissect  the  sac  from  below  upwards.     The  ^3 

incision  having  been  made,  the  skin  is  freed  for  a  short  | 

distance  at  either  side  and  held  apart  with  Rollet's  two 
small  retractors,  which  have  the  advantage  of  being  less 
in  the  way  than  the  self-retaining  ones,  their  position 
can  be  more  easily  controlled  and  altered  if  necessary, 
they  are  less  injurious  to  the  tissues,  and  they  avoid  the 
forward  displacement  of  the  edges  of  the  incision,  which  ^  „ 

the  self -retaining  retractors  cause,  and  which  increases 
the  depth  of  the  cavity  in  which  the  sac  lies.  The  crest  of 
the  lacrimal  bone  is  next  defined  with  the  finger,  the  incision 
is  carried  down  to  the  bone  immediately  in  front  of  it,  and  with 
Rollet's  rugine  (Fig.  252)  or  special  elevator  (Fig.  253)  the  inner 
wall  of  the  sac  with  the  periosteum  is  separated  from  its  bed  in  the 
lacrimal  groove.  The  sac  is  then  cut  with  scissors  as  low  down  as 
possible,  where  it  is  seized  with  an  artery  or  fixation  forceps,  drawn 
forwards,  and  its  attachments  dissected  upwards  with  the  scissors. 


CHAP.  XIX.]  THE   LACRIMAL    APPARATUS.  r,01 


After  the  removal  ol  the  sac,  the  lacrinial  gruove  and  siiiTouiKliiig 
parts  should  l)e  inspected  in  order  to  see  if  any  portion  may  have 
been  left.  Care  must  be  taken  during  the  dissection  of  the  sac 
not  to  go  too  deeply  or  too  much  towards  the  inner  canthus,  other- 
wise in  the  former  case  the  orbital  fascia  will  be  cut  through  as  shown 
by  the  appearance  of  orbital  fat,  and  in  the  latter  event  the  con- 
junctiva may  be  buttonholed  at  the  inner  canthus. 

After  extirpation  of  the  suppurating  lacrimal  sac,  a  source  of 
danger  to  the  eye  has  been  removed,  and  the  patient  has  been 
relieved  of  a  troublesome  and  disfiguring  complaint.  The  lacrima- 
tion  is  less  after  the  operation  than  before  it,  not,  as  has  been  stated, 
because  the  lacrimal  gland  undergoes  atrophy,  for  no  such  atrophy 
takes  place,  but  rather  owing  to  elimination  of  the  fifth  nerve  reflex 
from  the  walls  of  the  diseased  sac  and  from  the  inflamed  conjunctiva. 
Indeed,  unless  the  surface  of  the  eye  be  exposed  to  some  consider- 
able irritation,  e.g.  cold  wind,  foreign  body,  etc.,  or  there  be  some 
psychical  emotion,  the  lacrimation  is  in  no  way  disturbing,  notwith- 
standing the  complete  closure  of  the  lacrimal  passage  consequent 
on  the  operation.  Should  the  lacrimation  in  some  instances  be 
troublesome,  removal  of  the  palpebral  portion  of  the  lacrimal  gland 
is  indicated  (p.  594).  Eemoval  of  the  orbital  portion  of  the  gland 
is  seldom  needed,  as  its  functions  seem  to  cease  after  removal  of  the 
palpebral  gland,  probably  owing  to  closure  of  its  ducts  consequent 
on  removal  of  the  latter  gland.  Yet  a  retention  tumour  of  the 
orbital  gland  does  not  ensue. 

It  is  desirable  to  instruct  the  patient  that  he  should  inform  any 
surgeon  he  may  subsequently  consult  for  epiphora  that  his  lacrimal 
sac  has  been  removed,  lest  futile  and  perhaps  harmful  probing  of  the 
nasal  duct  should  be  attempted. 

Dacryocystorhinostomy ,  or  the  formation  of  an  opening  leading 
from  the  sac  into  the  nose  through  the  lacrimal  bone,  is  being  per- 
formed by  some  surgeons  as  a  substitute  for  removal  of  the  sac. 
In  Toti's  method  the  operation  is  performed  from  the  outside, 
whereas  West's  is  altogether  intranasal. 

Acute  Dacryocystitis  {^aKpvw,  to  weep  ;  Kvo-Ti?,  a  bladder). — 
Acute  inflammation  of  the  lacrimal  sac  most  usually  comes  on  when 
chronic  lacrimal  blennorrhoea  is  already  present.  Caries  of  the 
nasal  bones  may  cause  it,  and  it  occurs  idiopathically,  probably  as 
the  result  of  exposure  to  cold. 


.'502  DISEASES   OF    THE   EYE.  [chap.  xtx. 


The  region  of  the  lacrimal  sac  and  the  surrounding  integument 
become  swollen,  tense,  and  red,  and  these  conditions  often  spread 
to  the  lids,  giving  an  appearance  which  is  sometimes  mistaken  for 
erysipelas  ;  but  the  history  of  the  case,  showing  the  previous  exist- 
ence of  lacrimal  obstruction,  etc.,  will  assist  the  diagnosis.  Great 
pain  accompanies  the  inflammatory  process.  Gradually  the  region 
corresponding  with  the  lacrimal  sac  becomes  the  most  prominent 
part  of  the  swelling,  and  the  abscess,  pointing  there,  opens.  When 
the  pus  has  been  discharged  the  inflammation  subsides,  and  the 
opening  through  the  skin  may  either  close,  the  parts  resuming  their 
normal  functions,  or  the  opening  may  remain  as  a  permanent  fistula. 

The  difference  between  chronic  blennorrhoea  of  the  lacrimal  sac 
and  acute  dacryocystitis,  besides  the  fact  that  one  is  a  chronic  and 
the  other  an  acute  inflammatory  process,  is  that  the  former  process 
is  confined  to  the  mucous  membrane  of  the  sac,  while  in  the  latter 
the  submucous  tissue  is  involved,  with  phlegmonous  inflammation 
as  the  result. 

Treatment. — In  the  early  stages  poultices  and  purgatives  should 
be  employed.  As  soon  as  palpation  of  the  sac  indicates  the  presence 
of  pus,  it  must  be  evacuated.  This  can  be  effected  either  through 
the  canaliculus,  by  opening  it  up  to  its  entrance  into  the  sac,  or  by 
an  incision  through  the  integument  over  the  sac.  The  latter  is  the 
better  method,  as  it  admits  of  free  access  to  the  interior  of  the  sac. 
On  the  next  day  the  walls  of  the  sac  are  to  be  freely  touched  with 
solid  mitigated  nitrate  of  silver  ;  or  a  plug  of  cotton-wool  soaked 
in  a  strong  solution  of  nitrate  of  silver  may  be  inserted  into  its  cavity, 
and  left  there  for  some  hours  ;  or  various  astringent  solutions  may 
be  injected  into  the  sac.  The  aim  of  the  treatment,  whatever  it 
be,  is  to  secure  a  rapid  return  of  the  mucous  membrane  to  its 
normal  condition.  If  stricture  of  the  nasal  duct  be  present,  it  must 
be  treated  pari  passu.  By  these  means  the  discharge  from  the  sac 
is  arrested,  and  the  external  opening  gradually  closes. 

If  a  fistula  should  form,  it  may  be  made  to  close,  in  many  cases, 
by  simply  freeing  an  existing  stricture  of  the  nasal  duct ;  or,  it  may 
be  necessary  to  pare  its  edges,  and  bring  them  together  by  sutures ; 
or,  especially  if  there  be  a  long  fistulous  passage,  the  galvano-cautery, 
in  the  form  of  a  platinum  wire,  can  be  applied  with  advantage. 

Dacryoadenitis  {dak-pvw,  to  iceep ;  ddrjv,  a  gland),  or  Inflammation 
of  the  Lacrimal  Gland. — This  is  a  very  rare  affection.       It  occurs  in  an 


r-HAr.  XIX.]  THE    LACRIMAL    APPARATUS.  593 


acute  and  in  a  snb-acutc  form,  and  is  usually  symmetrical  in  each  eye. 
The  acute  form  is  characterised  by  swelling  of  the  upper  lid,  especially 
in  its  outer  tliird,  by  chemosis,  by  diminished  mobility  of  the  eyeball 
upwards  and  outwards,  with  displacement  downwards  and  inwards,  by 
local  pain  often  radiating  into  the  frontal  region,  and  by  pain  on  pressure 
over  the  gland.  On  pressure,  the  tuberous  and  swollen  gland  may  be 
felt,  unless  a?dema  of  the  lid  should  interfere.  In  the  sub-acute  form  there 
is  neither  ojdema  nor  chemosis,  and  little  or  no  pain,  and  the  diagnosis 
depends  on  the  presence  of  a  hard  and  lo])ulated  mass  under  the  outer 
tliird  of  the  iipper  lid,  which  may  displace  the  globe  and  interfere  with 
its  motion  upwards  and  outwards. 

Dacryoadenitis  occurs  in  gonorrhoea,  even  long  after  the  acute  stage 
of  the  latter  is  passed,  in  epidemics  of  mumps  with  or  without  parotitis, 
in  influenza,  diphtheria,  measles,  and  scarlatina.  In  all  these  instances 
it  must  be  regarded  as  the  result  of  toxic  absorption,  and  having  lasted 
from  about  three  to  fourteen  days  it  undergoes  resolution  with  complete 
recovery. 

Dacryoadenitis  may  also  be  caused,  without  any  conjunctivitis,  by 
dii'ect  infection  with  the  staphylococcus,  streptococcus,  or  pneumococcus, 
each  of  which  has  been  found  in  the  inflammatory  products,  and  these 
cases  are  liable  to  go  on  to  suppuration,  with  formation  of  abscess.  They 
are  usually  on  one  side  only. 

Finally,  cases  of  tubercular  dacryoadenitis  have  been  recorded.  The 
direct  clinical  diagnosis  of  these  cases  cannot  be  made — the  suspicion 
only  of  their  nature,  from  the  presence  of  tubercular  disease  in  other  parts 
of  the  system,  can  be  raised. 

Treatment. — Treatment  of  any  toxaemia  which  may  be  held  to  be 
present.  Locally  hot  fomentations  relieve  pain  and  promote  resolution. 
When  abscess  forms,  it  generally  points  in  the  conjunctival  fornix,  and  is 
to  be  opened  there.  Should  tubercle  be  suspected,  removal  of  the  entire 
gland  is  indicated. 

Tumours  of  the  Lacrimal  Gland. — Tumours  of  the  lacrimal  gland 
are  rare.  Sarcoma  is  the  most  common  of  the  new  growths  here,  with 
its  mixed  forms  fibro-,  myxo-,  adeno-,  and  lympho-sarcoma.  Adenoma 
is  also  common,  and  lyinphoma,  angioma,  and  some  other  varieties  have 
been  observed.  In  the  beginning,  the  outer  third  of  the  upper  lid  seems 
swollen,  but  palpation  shows  this  to  be  caused  by  a  tumour  behind  the 
lid,  but  not  in  it,  and  also  that  the  tumour  originates  in  the  orbit.  Gradually, 
by  pressure  of  this  growing  tumoiu%  the  eyeball  becomes  displaced  for- 
wards and  inwards,  and  its  motions  are  curtailed  in  the  upward  and  outward 
direction.  In  many  instances  the  growth  extends  backwards  into  the 
orbit  Ijehind  the  globe,  and  then  the  direction  of  the  displacement  is 
more  markedly  forwards.  The  tumour  may  become  fixed  to  the  orbital 
margin,  or  the  roof  of  the  orbit  may  be  involved  and  even  perforated,  and 
vision  may  be  affected,  if  the  optic  nerve  be  pressed  on. 

Treatment. — Extirpation  of  the  growth  is  indicated.   If  the  case  come 

under  care  at  an  early  stage,  the  tumour  can  be  reached  and  effectually 

removed,  either  through  an  incision  made  through  the  lid  parallel  to  the 

outer  half  of  the  orbital    margin  ;    or,   the  external  commissure  having 

38 


594 


DISEASES   OF    THE   EYE. 


[chap.    XIX. 


been  divided,  and  the  upper  lid  turned  up — through  an  incision  made  in 
the  conjunctival  fornix.  In  later  stages,  especially  when  the  tumour  has 
extended  deeply  into  the  orbit,  Kronlein's  operation  (p.  618)  is  indicated. 

Tubercular  Tumour  of  the  Lacrimal  Gland. — A  few  cases  of  tubercular 
tumour  of  the  lacrimal  gland  have  been  recorded.  The  tumour  presented 
itself  as  a  very  hard  mass,  about  the  size  of  an  almond,  freely  movable 
under  the  skin,  and  unattended  by  pain.  In  some  instances  the  history 
had  extended  over  several  years,  and  in  others  has  lasted  for  some  months 
only.  In  the  majority  of  the  cases  there  was  tubercular  disease  elsewhere 
in  the  system,  bvit  in  one  instance  there  was  none,  nor  was  there  any 
hereditary  disposition  to  tubercle. 

Treatment. — Extirpation  of  the  gland. 

Cysts  of  the  Lacrimal  Gland. — These  are  rare.  The  most  common 
of  them  is  Dacryops,  a  term  applied  to  a  retention  cyst,  which  occurs 
almost  exclusively  in  the  palpebral  portion  of  the  gland,  and  may  attain 
the  size  of  a  hazel  nut,  and  which  appears  as  a  more  or  less  transparent 
bluish  swelling  in  the  outer  part  of  the  upper  fornix. 

Treatment. — Excision  of  a  portion  of  the  outer  wall  of  the  cyst. 

Symmetrical  Chronic  Swelling  of  the  Lacrimal  and  Salivary  Glands. 
(Mikulicz's  disease). — In  this  remarkable  affection  there  is  enormous 
swelling  of  each  lacrimal,  parotid,  and  submaxillary  gland,  while  the  sub- 
lingual glands  and  small  salivary  glands  in  -the  cheek  are  also  swollen, 
the  whole  producing  a  striking  alteration  in  the  physiognomy  of  the 
patient.  The  disease  has  an  acute  and  a  chronic  form.  The  former 
may  run  its  course,  attended  by  some  fever,  in  a  week  or  ten  days,  and 
can  be  treated  with  hot  fomentations  locally,  and  salicylate  of  soda  inter- 
nally. The  chronic  form  is  reckoned  by  many  to  be  a  manifestation 
of  leiTcaemia  or  of  pseudo-leucaemia,  or  it  may  be  tubercular,  and  its  treat- 
ment is  in  this  way  indicated. 

Extirpation  of  the  Lacrimal 
Gland. — This  operation  is  performed 
by  making  an  incision  through  the 
integument  under  the  outer  third  of 
the  orbital  margin  ;  the  subjacent 
fascia  is  dissected  up,  the  gland  drawn 
forward  with  a  hook,  and  dissected  out 
with  a  scalpel.  Or,  if  it  be  considered 
sufficient  to  remove  the  palpebral 
portion,  this  can  be  done  from  the 
conjunctival  surface,  by  separating 
the  lids  widely  at  the  outer  canthus 
with  blunt  hooks,  while  the  patient 
looks  well  downwards  and  to  the  nasal 
side,  when  the  palpebral  gland  will  become  prominent  in  the  upper 
fornix   (Fig.  254)  ;  the  conjunctiva  over  it  is  then  incised,  and  the 


Fig.  254. 


CHAP.   XIX.]  THE  LACRIMAL   APPARATUS.  5 Of 


gland  can  be  seized  and  ont  out  with  scissoi's.  This  partial  removal 
may  be  performed  for  persistent  lacrimation  when  other  means  fail. 
As  ah-eady  stated,  when  a  large  tumour  of  the  gland  is  present, 
Kronlein's  operation  is  often  needed.  The  absence  of  tears,  which 
follows  upon  extirpation  of  the  lacrimal  gland,  is  not  serious  for 
the  eye  :  foi-  iioiinally  the  gland  secretes  very  little,  unless  undei- 
the  stimulus  of  a  fifth  nerve  or  psychical  reflex.  Under  other 
conditions,  the  surface  of  the  eye  is  kept  moist  mainly  by  the  con- 
junctival secretion,  which  consists  not  merely  of  mucus,  l)ut  of  a 
watery  fluid  sufflcient  even  if  there  be  no  secretion  of  tears — as 
in  extirpation  of  the  lacrimal  gland  where  there  is  paralysis  of  the 
fifth  nerve — to  keep  the  surface  of  the  eye  moist. 

Occasionally  removal   of  the   lacrimal   gland  is  followed  by   a 
rather  obstinate  miico-purulent  discharge  from  the  conjunctiva. 


OHAPTER    XX. 

DISEASES   OF   THE   ORBIT. 

The  position  of  the  eyeball  in  the  orbit  is  subject  to  individual 
variations.  As  a  rule  the  cornea  projects  very  slightly  beyond  an 
imaginary  line  drawn  from  the  upper  to  the  lower  margin  of  the 
orbit,  so  that  a  ruler  placed  in  this  position  would  touch  the  closed 
upper  lid  and  exercise  only  slight  pressure  on  it. 

Exophthalmos  or  Proptosis.^ — One  of  the  most  common  signs 
in  many  diseases  of  the  orbit  is  displacement  of  the  eyeball  forwards, 
w^hich  is  usually  accompanied  by  more  or  less  lateral  or  vertical 
displacement.  In  slight  degrees  of  proptosis  the  relative  positions 
of  the  eyes  can  be  best  compared  by  observing  the  level  of  the  cornea 
from  behind  and  above  the  patient's  head.  Instraments  (exoph- 
thalmometers)  have  been  devised  for  the  measurement  of  the 
amount  of  protrusion,  and  of  these  Hertel's  is  one  of  the  best. 

The  causes  of  true  exophthalmos  are  :  increase  in  volume  of  the 
orbital  contents,  or  diminution  in  the  capacity  of  the  orbit.  The 
prominence  of  an  enlarged  eyeball  due  to  high  myopia,  or  to  anterior 
staphyloma,  as  also  the  slight  degree  of  exophthalmos  w^hich  results 
from  relaxation  or  loss  of  tone  in  the  orbital  muscles  when  several 
of  them  are  simultaneously  paralysed,  are  not  reckoned  as  true 
exophthalmos.  Again,  the  physiological  forward  position  of  the 
eyes  sometimes  present  in  very  stout  persons  must  not  be  misin- 
terpreted. Eetraction  of  the  lids  which  follows  the  use  of  cocaine, 
and  w^hich  also  occurs  in  the  early  stage  of  exophthalmic  goitre,  and 
in  other  conditions  (p.  622)  may  produce  the  appearance  of  proptosis, 
without  any  real  displacement  of  the  eyeball. 

True  exophthalmos  from  increase  in  the  orbital  contents  may 
be  brought  about  by  inflammatory  exudation,  as  in  orbital  cellulitis, 
by   new    growths,   by   vascular    diseases    such    as    arterio-venous 

^   TT/so,  forwards  ;    Trrwcrts,  faUing. 
596 


CHAP.  XX.]  THE    ORBIT.  597 


aneurism  and  cavernous  sinus  thionibosis,  and  hv  haemorrhage 
or  emphysema,  the  result  of  injury.  Diminution  in  the  capacity 
of  the  orbit  as  a  cause  of  exophthahnos  is  most  commonly  due  to 
encroachment  on  it  from  disease  of  the  nasal  sinuses  and  in  rare 
cases  to  the  condition  known  as  Tower  Skull  (oxycephaly)  and  the 
still  more  rare  affection  Leontiasis  Ossium.  Exophthalmos  is  most 
frequently  met  with  as  a  unilateral  affection,  but  it  may  be  bilateral, 
as  in  exophthalmic  goitre,  in  the  later  stages  of  thrombosis  of  the 
cavernous  sinus,  in  pansinusitis,  and  also  in  symmetrical  tumours 
of  the  orbit  (lymphoma). 

Orbital  Cellulitis. — The  Sym-ptoms  of  this  affection  are  :  ery- 
sipelatous swelling  of  the  lids,  especially  of  the  upper  lid  ;  serous 
chemosis  ;  pain  in  the  obit,  increased  on  pressure  of  the  eyeball 
backwards ;  violent  facial  neuralgia  ;  exophthalmos,  with  impair- 
ment of  the  motions  of  the  eye  in  every  direction  ;  and  high  fever, 
sometimes  with  headache  and  vomiting. 

Vision  is  not  generally  affected,  except  when  accompanied  by 
optic  neuritis,  and  then,  too,  mydriasis  is  seen.  The  cornea  is 
often  completely  or  partially  anaesthetic. 

The  surgeon,  by  pressing  the  tip  of  his  fourth  finger  between  the 
eyeball  and  the  margin  of  the  orbit,  may  feel  a  more  or  less  resistant 
tumour.  This  gradually  increases  in  some  one  direction,  the  integu- 
ment in  that  position  becomes  redder,  fluctuation  becomes  pro- 
nounced, and  the  abscess  finally  opens  through  the  skin,  or  into  the 
conjunctival  sac,  the  pointing  being  usually  at  the  upper  and  inner 
angle  of  the  orbit.  Restoration  to  the  normal  state,  as  a  rule,  comes 
about ;  but  in  some  cases  complete  atrophy  of  the  optic  nerve 
supervenes.  Other  cases,  however,  recover  without  the  formation 
of  pus  ;  while  again,  thrombosis  of  the  cavernous  sinus,  or  even 
meningitis  or  cerebral  abscess  may  ensue. 

In  panophthalmitis  (p.  192),  as  in  orbital  cellulitis,  exophthalmos, 
loss  of  movement,  swelling  of  the  lids  and  chemosis  also  occur,  but 
in  panophthalmitis  these  symptoms  are  preceded  and  accompanied 
by  purulent  irido-cyclitis,  or  by  suppuration  of  the   cornea. 

Causes. — (1)  Idiopathic  [e.g.  cold)  ;  (2)  traumatic  (perforating 
injuries,  foreign  bodies)  ;  (3)  extension  of  inflammation  from  sur- 
rounding parts  (erysipelas,  diseased  tooth,  ethmoidal  cells)  ;  (4) 
metastasis  (pytemia,  metria)  ;  (5)  sequela^  of  fevers  (scarlatina, 
typhoid,  purulent  meningitis,  influenza).     The  majority  of  cases  of 


598  DISEASES   OF    THE   EYE.  [chap.  xx. 


orbital  cellulitis  are  due  to  infection  from  the  neighbouring  sinuses. 
The  frontal  sinus  is  the  one  most  frequently  affected,  the  anterior 
ethmoidal  and  maxillary  antrum  coming  next  in  order  of  frequency. 
Treatment. — Locally,  poultices  or  warm  fomentations ;  and, 
when  pus  has  formed,  its  earliest  possible  evacuation  by  a  deep 
incision  usually  close  to,  and  parallel  to,  the  inner  wall  of  the  orbit, 
followed  by  drainage  and  cleansing  of  the  cavity  with  hydrogen 
peroxide  or  antiseptic  solutions.  Even  in  the  earlier  stages,  if  there 
be  much  swelling  and  exophthalmos,  these  deep  incisions  should 
be  made  to  relieve  the  tension,  and  allow  the  pus,  if  it  does  form,  to 
find  its  way  more  readily  to  the  surface.  The  nasal  sinuses  should 
be  treated  if  necessary  by  endo-nasal  or  radical  methods.  We  have 
seen  cases  in  an  early  stage  yield  to  non-operative  endo-nasal 
treatment.  The  general  constitutional  treatment  suitable  to  each 
case  need  not  be  discussed  here. 

Tenonotis,  or  Inflammation  of  the  Capsule  of  Tenon,  is  an  uncommon 
affection,  the  symptoms  of  which  are  those  of  a  moderate  celhihtis  of  the 
anterior  part  of  the  orbit.  As  in  orbital  celluHtis,  the  hds  are  red  and 
swollen,  there  is  slight  exophthalmos,  with  restricted  mobility  of  the  eye, 
and  chemosis,  but  no  conjunctival  discharge.  The  diagnosis  (as  distin- 
guished from  cellulitis)  rests  on  the  slight  degree  of  exophthalmos,  as 
compared  with  the  great  loss  of  mobility,  and  relatively  well-marked 
chemosis.  In  the  early  stage,  before  the  inflammatory  symptoms  have 
declared  themselves,  the  patient  complains  of  periorbital  neuralgia,  fol- 
lowed by  a  sense  of  pressure  in  the  eye,  and  great  pain  on  attempting  to 
move  it,  so  much  so  that  the  eyes  are  kept  closed  and  immovable.  One 
or  both  eyes  may  be  affected,  and  relapses  are  common.  Vision  is  not 
affected  and  febrile  symptoms  are  much  milder  than  in  cellulitis.  The 
prognosis  is  good,  recovery  taking  place  in  about  a  week.  Sometimes 
suppuration  occurs,  and  a  small  sub-conjunctival  abscess  forms,  which 
generally  opens  upwards  and  inwards.  In  addition  to  the  serous  and  puru- 
lent varieties,  a  chronic  plastic  form  of  the  disease  has  also  been  met  with. 

Causes. — Chronic  rheumatism  (sometimes  with  effusion  into  a  joint), 
influenza,  and  in  rare  cases  tuberculosis.  The  suppurative  form  may  be 
traumatic,  or  may  follow  measles  or  scarlatina. 

Treatment. — A^^arm  fomentations,  and  a  light  bandage,  with  salicylate 
of  soda,  antipyrin,  or  quinine  internally. 

Thrombosis  of  the  Cavernous  Sinus  gives  rise  to  symptoms 
which  may  be  mistaken  for  those  of  an  orbital  process.  It  fre- 
quently spreads  to  the  opposite  side,  and  is  accompanied  by  cerebral 
symptoms.     The  affection  is  described  at  p.  502. 

Periostitis  of  the  Orbit. — Acute  periostitis  of  the  orbit  has  many 


CHAP.  XX.]  THE   ORBIT.  599 

symptoms  in  common  with  phlegmonous  inflammation  of  the  orbital 
connective  tissue,  which  generally  accompanies  it,  but  it  may 
usually  be  distinguished  from  the  latter  inflammation  occurring  in- 
dependently, by  the  fact  that,  in  it,  pressure  on  the  orbital  margin 
is  painful.  The  absence  of  this  tenderness,  however,  is  not  always 
conclusive  of  the  absence  of  periostitis,  especially  when  the  latter 
is  restricted  to  the  deep  parts  of  the  orbit.  In  periostitis  the  eye- 
lids are  not  usually  so  swollen  as  in  inflammation  of  the  orbital 
tissues.  Suppuration  may  take  place,  necrosis  in  consequence  of 
detachment  of  the  periosteum  may  come  on,  and  communications 
with  the  neighbouring  cavities  may  be  formed. 

In  secondary  syphilis,  or  in  later  stages  of  the  disease,  a  syphilitic 
gumma  of  the  orbital  wall  may  form.  This  is  accompanied  by 
violent  frontal  neuralgia  or  headache,  increasing  at  night.  Proptosis 
occurs,  with  marked  loss  of  motion  in  the  eyeball  in  one  or  more 
directions.  This  early  loss  of  motion  is  a  very  characteristic  symp- 
tom, and  serves  to  assist  in  the  diagnosis  between  gumma  and 
other  orbital  tumours.  It  is  probably  due  to  an  extension  of  the 
inflammation  to  the  connective  tissue  of  the  orbit,  and  to  the  muscles 
themselves. 

The  symptoms  suggestive  of  gummatous  periostitis  of  the  orbit 
are  : — A  rapidly  increasing  proptosis,  wdth  displacement  of  the  globe 
downwards  and  forwards,  and  much  loss  of  motion  of  the  eye,  while 
on  palpation  the  sensation  is  given  to  the  finger  of  a  tumour  in  the 
roof  of  the  orbit,  ^vhere  gummata  most  commonly  are  situated. 
Also,  thickening  of  the  upper  margin  of  the  orbit,  with  pain  on  pres- 
sure on  the  roof  of  the  orbit,  and  radiating  periorbital  pain  at  night. 
Periostitis  of  a  chronic  form,  and  without  tendency  to  suppura- 
tion, occurs  most  commonly  in  persons  with  a  constitutional  rheu- 
matic tendency.     It  is  accompanied  by  pain  in  and  about  the  orbit, 
with  increased  tenderness  on  pressure  backwards  of  the  eyeball. 
Exophthalmos,  and  all  other  outward  signs,  are  usually  wanting. 
The  Profjnosis  depends  much  on  the  seat  of  the  inflammation. 
If  this  be  in  the  deep  parts  of  the  orbit,  thickening  of  the  periosteum 
may  cause  permanent  protrusion  of  the  eyeball ;    extension  of  the 
inflammation  to  the  optic  nerve  may  result  in  optic  atrophy  ;    the 
orbital  muscles,  or  the  nerves  which  supply  them,  may  be  implicated, 
with   consequent  paralysis ;    or,   finally,   the  inflammation   of  the 
periosteum  may  strike  into  the  meninges  of  the  brain.     When  the 


600  DISEASES    OF    THE   EYE.  [chap.  xx. 


inflammation  is  near  the  margin  of  the  orbit,  early  evacuation  of  pus, 
if  it  have  formed,  reduces  the  process  within  safe  bounds  ;  and  this 
position  is  one  of  less  danger  in  respect  of  its  surroundings,  than  if 
the  process  be  deep  in  the  orbit. 

Causes. — Periostitis  of  the  orbit  may  be  caused  by  blows  or  other 
traumata,  by  extension  from  neighbouring  cavities,  by  syphilis,  or 
by  rheumatism. 

Treatment. — Warm  fomentations.  Exit  given  to  pus,  if  possible. 
Constitutional  treatment.  Incision  along  the  orbital  margin,  and 
separation  of  the  periosteum,  with  drainage,  may  shorten  the  pro- 
cess, if  the  foregoing  measures  do  not  give  relief. 

Caries  of  the  Orbit  is  very  frequently  the  result  of  periostitis, 
but  often  commences  in  the  bone,  and  in  either  case  is  usually  due 
to  tubercular  disease.  It  is  also  seen  in  very  late  syphilis.  A 
trauma  is  sometimes  the  immediate  cause  of  its  onset. 

Caries  may  attack  any  part  of  the  orbital  walls,  its  favourite 
seats  being  the  margin  above  and  to  the  outside,  or  below  and  to 
the  outside.  The  latter  situation  is  a  common  one  for  tubercular 
disease.  When  it  is  seated  deeply  in  the  orbit,  it  often  causes  ex- 
ophthalmos and  pain.  At  the  margin  of  the  orbit  it  produces  oedema 
and  swelling  of  the  eyelids,  with  conjunctivitis  ;  suppuration  comes 
on,  and  the  abscess  finally  opens  through  the  integument  or  con- 
junctiva. A  fistula  is  apt  to  remain  for  a  length  of  time,  and,  the 
skin  being  drawm  into  this,  ectropion  of  the  lid  is  produced.  If  a 
portion  of  dead  bone  come  away,  the  resulting  cicatrix  is  liable  to 
maintain  the  ectropion  (p.  574). 

Treatment. — The  evacuation  of  purulent  collections  at  the  earliest 
possible  moment — if  they  be  deep  in  the  orbit,  by  the  careful  in- 
troduction of  a  long  bistouri  parallel  to  the  orbital  wall — the  in- 
sertion of  a  drainage-tube,  and  the  regular  washing  out  of  the 
cavity  with  antiseptic  solutions,  until  no  more  rough  or  bare  bone 
can  be  felt  with  the  probe.  If  the  case  be  very  tedious,  Kronlein's 
operation  may  permit  of  the  removal  of  sequestra  with  greater 
ease  and  security. 

Injuries  of  the  Orbit.— Wounds  of  the  soft  parts  in  the  supra- 
orbital region,  involving  the  supra-orbital  nerve,  were  formerly 
held  to  be  capable  of  producing  a  reflex  amaurosis  (p.  391),  and 
many  such  cases  have  been  recorded  under  the  name  of  supra-orbital 
amaurosis.     But  the   blindness  in  the  cases  recorded  was  brought 


CHAr.  XX.]  THE    OIUilT.  m\ 


about  in  some  other  way — c.q.  injury  to  the  optic  nerve  in  the  optic 
foramen  by  the  concussion,  or  by  a  fracture  of  the  margin  of  the 
foramen,  orbital  periostitis,  concomitant  injury  to  the  eyeball  itself, 
facial  erysipelas,  intracranial  lesions,  and  so  on. 

It  may  be,  however,  that  a  functional  amblyopia,  or  amaurosis, 
similar  to  that  occasionally  seen  after  long-continued  blepharospasm 
(p.  105),  has  sometimes  been  present. 

Perforating  injuries,  more  especially  of  the  roof  of  the  orbit 
through  the  eyelids,  by  prods  of  walking-canes,  etc.,  and  the  lodgment 
of  foreign  bodies  in  the  orbit  are  serious  accidents.  They  are  liable 
to  be  followed  by  phlegmonous  inflammation  ;  or,  if  a  pointed 
weapon  (stick,  sword-cane,  etc.)  has  been  pushed  into  the  orbit  with 
some  force,  it  may  divide  the  optic  or  motor  nerves,  or  injure  the 
muscles,  or  it  may  even  pass  through  the  bony  wall  and  perforate 
the  brain,  with  fatal  result. 

It  is  remarkable  what  large  foreign  bodies  may  be  concealed  in 
the  orbit.  We  have  removed  large  pieces  of  wood,  which  had  lain 
in  the  orbit,  in  one  case  for  weeks,  in  another  for  several  months 
without  inflammatory  symptoms.  In  the  first  there  was  even  no 
exophthalmos. 

Haemorrhage  into  the  Orbit  may  occur  from  injury,  and  may 
cause  exophthalmos,  or  atrophy  of  the  optic  nerve  from  pressure. 
Such  orbital  haemorrhages  are  sometimes  met  with  at  birth,  as  the 
result  of  complicated  labour,  especially  when  the  forceps  has  been 
applied.  Spontaneous  haemorrhages  have  been  observed  in  old 
people  with  diseased  arteries,  in  whooping  cough,  in  haemophilia, 
and  in  haemorrhagic  small-pox  ;  and  sub-periosteal  haemorrhages 
occur  in  Barlow's  disease. 

Haemorrhage  in  the  Eyelids,  with  ecchymosis  of  the  conjunc- 
tiva, commonly  known  as  a  black  eye,  is  usually  the  result  of  blows 
with  large  blunt  objects,  such  as  the  closed  hand.  The  object  which 
causes  the  injury  is  arrested  by  the  margin  of  the  orbit,  against 
which  the  tissues  are  bruised,  while  the  eye  usually  escapes.  On 
the  other  hand,  when  the  object  is  small  or  sharp,  it  enters  the  orbit, 
and  injures  the  eyeball,  and  there  is  less  tendency  to  external 
bruising. 

Deep  Fractures  of  the  Orbit,  in  the  neighbourhood  of  the  optic 
foramen,  may  cause  atrophy  of  the  optic  nerve  without  any  other 
symptom.     The  atrophy  may  not  appear  for  some  weeks,  hence 


602  DISEASES    OF    THE   EYE.  [chap.  xx. 


the  necessity  for  a  cautious  prognosis  in  cases  of  head  injuries. 
Where  the  optic  atrophy  is  the  result  of  haemorrhage  into  the 
sheath  of  the  optic  nerve,  a  dark  greyish  red  ring  may  be  visible 
round  the  margin  of  the  optic  papilla. 

Emphysema  of  the  orbit,  or  of  the  lids,  or  of  both,  sometimes 
occurs  from  injury  of  the  ethmoid,  or  from  rupture  of  the  mucous 
membrane  of  the  lacrimal  duct.  The  emphysema  develops  after  the 
injury  when  a  strong  expiratory  effort,  such  as  blowing  the  nose, 
is  made.  Emphysema  also  occurs  in  perforation  of  the  ethmoid 
from  disease,  and  even,  although  rarely,  without  previous  disease. 

Treatment. — Foreign  bodies  should  be  removed  by  dilatation 
of  their  wounds  of  entrance,  or  by  the  formation  of  a  new  passage 
through  the  conjunctival  fornix — and  great  care  should  be  taken 
to  prevent  the  onset  of  inflammation,  or  to  keep  it  within  safe 
bounds.  A  pressure  bandage,  and  the  exercise  of  caution  when 
blowing  the  nose  for  a  little  while,  is  all  that  is  required  in  emphy- 
sema. 

Enophthalmos,  or  sinking  of  the  eye  back  into  the  orbit,  ^A'ith 
apparent  narrowing  of  the  palpebral  fissure,  occurs  to  a  certain  extent 
in  extreme  emaciation,  in  Asiatic  cholera,  in  paralysis  of  the  S3^mpathetic, 
and  in  facial  hemiatrophy.  But  it  has  been  observed  to  an  extreme 
degree  as  a  result  of  blows  on  the  eye,  or  on  the  lower  orbital  margin 
(Traumatic  Enophthalmos)  ;  and  in  these  cases  atrophy,  or  cicatricial 
contraction  of  the  retrobulbar  cellular  tissue,  or  paralysis  of  Miiller's 
muscle,  from  injury  of  the  sympathetic  nerve,  have  been  held  accountable 
for  the  condition.  In  some  cases,  it  is  due  to  fracture  or  depression  of  a 
portion  of  the  orbital  wall. 

Enophthalmos  is  sometimes  congenital ;  it  is  also  present,  occasionally 
in  intermittent  exophthalmos  (p.  609),  when  the  patient  is  in  the  erect 
position,  and  after  removal  of  retrobulbar  tumours. 

*  Tumours  of  the  Orbit.— In  the  Diagnosis  of  an  Orbital  Tumour 
three  questions  present  themselves  :— First,  Is  a  tumour  of  the  orbit 
present  ?  Secondly,  Is  the  new  growth  confined  to  the  orbit,  or 
does  it  extend  to  neighbouring  cavities  ?  and  Thirdly,  Of  what  kind 
is  the  new  growth  '!  The  diagnosis  as  regards  any  of  these  points 
does  not  often  occasion  much  difficulty  in  advanced  stages  of  the 
disease,  especially  where  the  growth  occupies  the  anterior  part  of 
the  orbit,  or  protrudes  from  it.  It  is  rather  in  the  early  and  middle 
stages  that  difficulties  in  diagnosis  present  themselves,  and  attention 
will  here  be  mainly  directed  to  those  stages. 


CHAP.  XX.]  THE    ORBIT.  003 


Exophthalmos  is,  of  the  signs  by  wliich  the  presence  of  an  oilntal 
tumour  is  diagnosed  in  its  early  stages,  by  far  the  most  important, 
because  it  is  the  most  constant.  In  the  earliest  stages  of  a  growth 
which  commences  in  the  deepest  part  of  the  orbit  there  may  be,  it 
is  true,  no  exophthalmos,  while  other  symptoms — defects  of  sight, 
pain,  loss  of  motion — may  already  be  present ;  but  when  the  growth 
attains  to  certain  dimensions,  or  if  in  the  anterior  part  of  the  orbit 
there  be  even  a  small  tumour,  the  eyeball  must  be  pushed  out  of 
its  place. 

An  important  diagnostic  point  in  connection  with  the  exophthal- 
mos caused  by  a  tumour  is  that,  unless  it  be  within  the  muscular 
cone,  its  direction  is  almost  always  oblique  and  not  straight  for- 
wards ;  for  orbital  tumours  commonly  tend  to  develop  more  along 
some  one  w^all  of  the  orbit  than  along  the  others,  and  hence  the 
eyeball  becomes  pushed  towards  the  opposite  side  as  well  as  for- 
wards. In  cellulitis,  a?dema  of  the  orbital  tissues,  Graves'  disease, 
and  paralytic  proptosis,  the  exophthalmos  has  a  direction  straight 
forwards.  Tumours  growing  from  the  apex  of  the  orbit  may,  in 
their  early  stages,  cause  no  obliquity  of  direction  in  the  displace- 
ment of  the  globe,  and  some  tumours  do  not  do  so  even  in  an  ad- 
vanced stage  of  their  growth  ;  but  these  cases  are  exceptional. 
Tumours,  too,  situated  altogether  within  the  muscular  cone,  of 
wliich  the  most  common  are  tumours  of  the  optic  nerve,  need  not 
cause  any  lateral  displacement  of  the  globe. 

Again,  the  exophthalmos  caused  by  an  orbital  tumour  usually 
increases  in  degree  slowly  and  gradually,  differing  in  this  respect 
from  exophthalmos  due  to  most  of  the  other  causes,  in  which  either 
a  sudden  or  a  rapid  development  of  the  proptosis  is  the  rule. 

While  tumours  are  sometimes  present  in  both  orbits,  especially 
lymphoma  or  lympho-sarcoma,  yet  it  is  infinitely  more  common  for 
one  orbit  alone  to  be  diseased  ;  and  hence  monolateral  exophthalmos 
is  suggestive  of  orbital  tumour. 

Palpation  in  the  Orbit  often  provides  a  valuable  sign,  should  the 
new  growth  have  come  within  reach  in  the  anterior  part  of  the 
cavity.  In  many  cases,  indeed,  there  is  no  difnculty  whatever  in 
recognising  the  presence  of  an  orbital  tumour,  by  this  means,  the 
sensation  obtainable  by  the  tip  of  the  surgeon's  finger  pressed  into 
the  orbit  being  very  definite  ;  in  some  the  tumour  can  only  be  felt 
when  the  patient  is  ana3stlietised ;    but  in  other  cases  the  evidence 


604  DISEASES    OF    THE   EYE.  [chap.  xx. 

is  not  so  clear,  and  a  reasonable  doubt  may  exist  as  to  whether  any 
abnormal  resistance  is  met  with.  By  palpation  we  may  gain  some 
knowledge  of  the  position,  extent,  shape,,  and  consistence  of  the 
tumour,  and  whether  it  be  adherent,  either  to  the  walls  of  the  orbit 
or  to  the  eyeball.  It  is  important,  when  practicable,  to  compare 
the  result  of  examination  of  the  diseased  orbit  with  the  condition 
of  the  sound  orbit ;  and  this  can  be  done  to  greater  advantage  if 
palpation  of  the  orbits  be  performed  simultaneously  with  a  finger 
of  each  hand. 

Radiography  has  been  successfully  employed  in  some  cases  for 
the  diagnosis  of  retrobulbar  growths. 

Derangements  of  Vision  are  often,  but  by  no  means  always, 
present  in  the  early  and  middle  stages  of  the  growth  of  an  orbital 
tumour.  Their  occurrence  depends  frequently  on  the  rapidity  of 
the  growth  of  the  tumour,  rather  than  ujDon  its  size.  In  an  early 
stage  of  a  rapidly  increasing  tumour,  the  sudden  stretching  of,  and 
pressure  on,  the  optic  nerve  may  produce  absolute  blindness ; 
while  in  another  case,  with  an  equal  degree  of  proptosis,  but  which 
has  been  brought  on  by  a  slowly  growing  tumour,  vision  may  be 
unaffected,  by  reason  of  the  optic  nerve  becoming  gradually  ac- 
customed to  the  change.  Yet  slowly  growing  tumours,  which 
spring  from  the  optic  nerve  or  its  neighbourhood,  or  from  the  deepest 
part  of  the  orbit,  are  competent,  by  direct  pressure  on,  or  by  implica- 
tion of  the  optic  nerve,  to  cause  serious  loss  of  sight,  even  in  an 
early  stage,  and  with  but  little  exophthalmos.  Optic  neuritis,  and, 
later  on,  optic  atrophy,  are  occasionally  discovered  with  the  ophthal- 
moscope. Diplopia  is  often  present  when  the  globe  is  at  first 
displaced,  but  disappears  when  the  exophthalmos  becomes  extreme 
or  the  vision  defective. 

Pain  is  a  symptom  sometimes,  but  by  no  means  always,  present 
in  cases  of  orbital  tumours.  It  is  especially  liable  to  be  complained 
of  when  the  growth  is  increasing  rapidly  in  size,  even  though  it  may 
not  have  attained  to  great  dimensions.  The  pain  is  then  often  of 
a  neuralgic  kind,  and  very  severe,  from  the  unaccustomed  pressure 
on  branches  of  the  fifth  nerve  in  the  orbit. 

Loss  of  Power  of  Motion  of  the  Eyeball  is  a  very  cammon  symp- 
tom in  cases  of  orbital  tumours.  It  is  caused  in  some  cases  by  the 
mechanical  ol)struction  offered  by  the  tumour,  as  a  result  of  which 
motion  of  the  eyeball  becomes  defective  towards  the  side  of  the  orbit 


PHAr.  XX.]  THE   ORBIT.  00". 


on  \yhicli  thi'  lu-w  growth  is  situated.  In  other  cases  the  loss  of 
motion  is  caused  by  stretchini^  of  the  muscles  from  the  exophthalmos, 
or  ])y  implication  of  IIkmii  in  the  new  growth,  or  by  atrophy  of 
their  tissue,  or  by  paralysis  of  the  orbital  nerves  from  pressure. 

When  there  is  little  or  no  loss  of  motion,  while  the  proptosis  is 
marked,  the  conclusion  wvav  be  drawn  that  the  tunioui-  lies  within 
the  nuiscular  cone. 

In  the  later  stages  the  exophthalmos  may  become  so  great  that 
the  eyelids  no  longer  cover  the  eyeball  sufficiently,  and  a  purulent 
keratitis  may  set  in  which  may  end  in  loss  of  the  eye.  The  bulbar 
conjunctiva  below  the  cornea  becomes  cedematous,  bulges  forwards, 
and  becomes  covered  with  crusts,  and  the  lower  lid  becomes 
everted. 

In  every  case  the  history,  the  rapidity  of  growth,  and  the  age 
and  general  condition  of  the  patient  are  important  items  for  con- 
sideration. 

Diagnosis  of  the  Nature  of  an  Orbital  Tumour. — As  regards  the 
nature  of  the  growth  which  may  be  present,  it  must  be  admitted 
that  in  many  instances,  in  the  early  stages  of  a  deeply  seated  tumour, 
we  have  to  rest  content  with  an  indefinite  or  provisional  diagnosis, 
unless  an  exploratory  operation,  such  as  aspiration,  or  harpooning 
of  the  mass,  is  practicable. 

Primary  tumours  of  the  orbit  may  be  conveniently  described 
under  the  following  heads  : — Cysts,  solid  tumours,  pulsating  ex- 
ophthalmos, symmetrical  tumours,  tumours  of  the  optic  nerve,  and 
tumours  of  the  lacrimal  gland. 

Orbital  Cysts  are  usually  congenital  (Dermoids,  Encephalocele, 
Serous),  but  may  be  acquired  (Hydatid,  Cysticercus). 

Dermoid  Cysts  are  those  most  frequently  found.  Although 
congenital,  they  do  not  often  grow  to  any  size  until  the  age  of 
puberty  or  later,  and  may  then  for  the  first  time  give  rise  to  trouble- 
some symptoms.  They  are  smooth  rounded  tumours  which  grow 
slowly,  and  finally  reach  very  considerable  size,  and  then  bulge  out 
between  the  eyeball  and  margin  of  the  orbit.  Pressure  upon  this 
protruding  part  causes  it  to  diminish,  while  the  exophthalmos  is  at 
the  same  time  increased,  and  distinct  fluctuation  in  the  protruding 
part  can  be  felt.  The  growth  of  the  cyst  is  unaccompanied  by  pain 
or  other  inconvenience.  It  may  adhere  to  the  periosteum  and  cause 
bony  irregularities,  or  even  perforate  the  loof  of  the  orbit.     The  con- 


000 


DISEASES    OF    THE   EYE. 


[chap.   XX. 


tents  are  generally  either  serous  or  honey-like,  and  occasionally  hairs 
and  other  epidermic  formations  have  been  found  in  them. 

Hernia  Cerebri,  cither  in  the  form  of  meningocele  or  of  encephalocele, 
may  invade  the  orbit.  Its  most  common  situation  is  the  upper  and  inner 
angle  of  the  orbit,  to  which  it  gains  access  through  the  suture  between 
the  frontal  and  ethmoid  bones.  It  appears  as  a  fluctuating,  often  trans- 
parent, pulsating  congenital  tumour.  Sometimes  the  opening  in  the  bones 
can  be  felt  around  its  base.  Pressure  upon  it  causes  it  to  disappear,  but 
gives  rise,  at  the  same  time,  to  symptoms  of  cerebral  irritation,  or  pressure. 

A  congenital  tumour  in  the 
upper  inner  angle  of  the  orbit 
must  be  regarded  with  sus- 
picion, lest  it  be  a  cerebral 
hernia,  even  though  it  do  not 
pulsate,  or  on  pressure  cause 
cerebral  symptoms.  In  the 
large  cerebral  hernise,  death  in 
the  first  few  days  of  life  is  the 
rule. 

Cysts  with  Anophthabnos. — 
These  appear  as  serous  cysts, 
which  project  into   the  lower 
lid,  giving  it  a  slightly  bluish 
tinge.       They    are    associated 
with    so-called    anophthalmos 
(Fig.  255),    in  which,  in  spite 
of  the  name,  a  small  or  rudi- 
mentary   eyeball     is     always 
found.       The    cavity    of    the 
cyst  frequently  communicates 
with  the  interior  of  the  eye, 
and  contains  retina  more  or  less  altered   and  thrown  into  folds.     These 
cases  are  regarded  as  encysted  colobomata  (p.   223).      Other  cases  are 
believed  to  arise  from  foetal  inclusion  of  a  portion  of  the  lacrimal  sac. 

Parasitic  Cysts  are  usually  caused  by  the  echinococcus,  while  the  cysti- 
cercus  is  much  rarer  in  the  orbit.  Several  cases  of  the  former  have  been 
observed  in  England.  The  cysts  are  generally  deeply  situated,  and  the 
first  symptom  is  severe  pain  in  the  head,  like  hemicrania.  Their  growth 
is  very  slow,  and  the  presence  of  a  hydatid  thrill  is  very  rare.  The  fluid 
obtained  by  aspiration  may  contain  booklets  or  scolices. 

Treatment. — The  cyst  should  be  removed  in  toto,  if  possible. 
For  this  purpose,  Kronlein's  operation  (p.  618)  may  be  resorted  to. 
Or,  a  horizontal  incision  may  be  made  along  the  orbital  margin 
through  the  eyelid,  in  order  that  the  cavity  of  the  orbit  may  be 
reached  ;  or  two  perpendicular  incisions  at  either  canthus  through 
the  upper  lid  may  be  made,  and  the  latter  turned  upwards.     With 


Fig.  255. — A  case  of  so-called  anoph- 
thalmos, with  a  cyst  in  the  left 
lower  lid. 


CTTAr.   xx.l  THE    ORBIT.  007 


liooks  oi  luiTcps,  and  sc;i1i)l'1  or  scissors,  the  cyst  wall  must  then  l)e 
caiefullv  separated  from  all  adhesions.  If  it  cannot  be  removed 
entire,  as  large  a  portion  of  the  wall  as  possible  should  be  taken 
away,  and  the  contents  evacuated  by  gentle  pressure  backwards  of 
the  eyeball,  and  the  sac  washed  out  two  or  three  times  daily  with 
an  antiseptic  solution,  until  all  discharge  has  ceased.  The  above 
treatment  does  not,  of  coui'se,  a])])ly  to  encephalocele.  which  should 
not  be  interfered  with. 

Solid  Tumours  of  the  orl)it  are  in  most  instances  malignant 
(sarcoma,  endothelioma),  but  may  be  benign  (exostosis,  angioma, 
fibroma).  They  vary  in  consistency  from  the  softness  of  the  angio- 
mata,  to  the  dense  hardness  of  the  ivory  exostoses. 

Exostoses  occur  as  the  result  of  faulty  development  of  the  bones, 
and  also  without  any  apparent  cause,  and  are  usually  of  the  kind 
known  as  ivory  exostoses.  Three-fourths  of  them  begin  before  the 
twenty-fifth  year  of  age.  They  spring  most  commonly  from  the 
ethmoid  or  from  the  frontal  bones,  especially  tjie  frontal  sinus,  and 
have  a  broad  base,  but  are  sometimes  pedunculated. 

All  the  bony  tumours  give,  of  course,  the  sensation  of  dense 
hardness  to  the  touch  ;  but  there  are  some  malignant  growths  of 
such  hardness  that  it  may  not  be  easy  to  tell  them  from  the  osteo- 
mata  by  palpation.  And  here  a  Kontgen  ray  examination  will  be 
necessary.  The  growth  of  an  orbital  osteoma  is  excessively  slow, 
in  many  instances  commencing  in  infancy,  and  lasting  into  advanced 
life.  In  addition  to  the  dense  hardness  of  these  tumours,  the  de- 
ciding points  in  the  diagnosis  are  their  smooth,  usually  globular, 
and  somewhat  nodulated  surface,  along  with  their  immobility,  and 
direct  connection  with  the  walls  of  the  orbit,  all  ascertainable  by 
the  touch. 

Operative  interference,  in  cases  of  exostosis  of  the  orbit,  is  only 
justifiable  when  the  tumour  does  not  grow  from  the  roof  of  the  orbit 
(as  it  then  often  involves  the  cranial  cavity),  and  when  there  is 
reason  to  think  that  it  is  attached  to  the  orbital  wall  by  a  narrow 
base  or  pedicle.  Several  instances  are  on  record  in  which  the  growth 
has  become  spontaneously  separated  by  necrosis  of  its  pedicle.  Be- 
yond destruction  of  the  eyeball  there  is  no  danger  associated  with 
these  tumours,  even  if  their  growth  take  an  intracranial  direction  ; 
but  they  cause  serious  disfigurement,  and  often  much  pain. 

Angiomata  may  be  simple  or  cavernous.     They  are  usually  soft, 


008  DISEASES    OF    THE   EYE.  [chap.   xx. 


comjn'essible,  and  painless,  are  very  slow  in  their  growth,  and  do 
not  give  rise  to  pulsation  or  bruits.  The  teleangiectases,  or  simple 
tumours,  are  usually  congenital,  and  are  often  merely  extensions  into 
the  orbit  of  angiomata  of  the  eyelid.  The  cavernous  form  is  often 
encapsuled.  A  few  cases  of  lymphangioma  have  also  been  met  with 
in  the  orbit. 

Sarcoma. — Malignant  tumours  of  the  orbit  are  nearly  always 
sarcomata,  many  different  varieties  of  which  are  met  with.  Sarcoma 
may  develop  in  the  connective  tissue  in  any  part  of  the  orbit,  most 
frequently,  perhaps,  in  the  periosteum  and  in  the  connective  tissue 
about  the  lacrimal  gland.  Or  it  may  arise  from  the  endothelium  of 
the  vessels  (endotheliomata),  and  if  very  vascular,  it  may  pulsate, 
but  without  a  murmur.  These  malignant  tumours,  after  destruc- 
tion of  the  eyeball  by  pressure,  or  by  phthisis  following  ulceration  of 
the  cornea,  attack  the  bony  walls  of  the  orbit  and  its  surroundings. 

The  early  extirpation  of  the  tumour  with  complete  evisceration 
of  the  orbital  contents  affords  the  only  prospect,  and  that  a  slight 
one,  of  saving  the  patient's  life. 

Some  forms  of  sarcoma,  however,  are  non-malignant,  especially 
those  which  lie  free  in  the  orbit  and  arise  from  the  connective  tissue. 
Indeed,  Panas  held  that  many  cases  of  sarcoma,  as  also  of  lymphade- 
noma  of  the  orbit,  are  due  to  infectious  principles,  toxins,  or  microbes, 
and  are  amenable  to  medical  treatment  by  mercury,  iodine,  arsenic, 
or  toxitherapy.  So  much  certainly  must  be  admitted — namely,  that 
cases  now  and  then  present  themselves,  with  all  the  signs  and  symp- 
toms of  orbital  tumour,  which  ultimately  undergo  a  purely  spon- 
taneous cure,  or  one  unexpectedly  brought  about  by  iodide  of 
potassium. 

In  some  of  these  cases  of  pseudo-tumour  no  tumour  is  found 
in  spite  of  the  existence  of  exophthalmos,  etc.,  while  in  others  a 
chronic  inflammatory  condition  of  the  connective  tissue  alone  exists, 
which  may  be  syphilitic  or  tubercular.  We  have  ourselves  seen  a 
large  sarcoma-like  orbital  tumour,  which,  on  removal,  proved  to  be 
merely  a  mass  of  inflammatory  tissue. 

Carcinoma  of  the  orbit,  unless  originating  in  the  lacrimal  gland,  is 
always  secondary  to  carcinoma  elsewliere  in  the  body.  Paralysis  of  the 
external  rectus  may  be  an  early  result  of  such  a  growth.  We  have  seen 
it  occur  after  removal  of  a  carcinoma  of  the  breast. 

Symmetrical  Tumours  of  the  Orbits. — With  the  exception  of  tumours 
of  the  lacrimal  glands,  and  possibly  of  rare  instances  of  metastatic  tumours, 


Chap,  xx.j  THE   ORBIT.  (ioO 


symmetrical  tumours  of  the  orbits  are  almost  invariably  lymphoraataor 
lymph-adenomata,  occurring  in  leucieniia  or  in   psoudo-leucasmia. 

Pulsating  Exophthalmos. — Tliis  is  most  frequently  due  to  arterio- 
venous aneurism  in  the  cavernous  sinus,  which  may  })e  either  trau- 
matic or  spontaneous.  The  symptoms  are  :  proptosis  ;  the  presence 
of  peculiar  bruits,  usually  continuous  but  with  systolic  reinforce- 
ment, which  can  be  heard  with  the  stethoscope  over  the  orbit, 
and  usually,  also,  over  a  more  or  less  extensive  portion  of  the 
skull ;  engorgement  of  the  veins  of  the  eyelids  ;  pulsation,  apparent 
in  the  eyeball,  or  at  some  point  of  the  orbital  aperture,  and  often  a 
thrill  which  can  be  felt  with  the  fingers  placed  on  the  upper  lid. 
The  pulsation  and  thrill  may  be  diminished  or  abolished  by  pressure 
on  the  common  carotid.  The  two  latter  symptoms  are  occasionally 
absent  during  the  whole,  or  part,  of  the  progress  of  the  case.  Para- 
lysis of  the  ocular  muscles,  most  commonly  of  the  external  rectus, 
often  occur.  There  may  be  retinal  venous  engorgement  or  even 
papillitis  with  defective  vision.  The  same  symptoms  may  be 
exceptionally  caused  by  aneurism  of  the  carotid  in  the  cavernous 
sinus,  aneurism  of  the  ophthalmic  artery  at  its  origin  or  in  the  orbit, 
and  by  cirsoid  aneurisms,  or  by  very  vascular  malignant  tumours. 
It  is  also  possible  that  obstruction  of  the  cavernous  sinus  from  other 
intracranial  causes  may  produce  these  symptoms. 

Haemorrhage  is  liable  to  prove  fatal  in  these  cases. 

Treatment. — Ligature  of  the  common  carotid  affords  the  best 
prospect  of  cure.  Digital  compression  of  the  same  vessel  has  pro- 
duced cure  in  some  cases.  Spontaneous  cure  has  been  observed 
occasionally  in  cases  of  arterio-venous  aneurism. 

Intennittent  Exophthalmos. — This  is  due  to  a  varicose  condition  of  tlie 
veins  of  the  orbit.  The  exophthalmos  only  occurs  on  stooping,  or  on 
exertion,  and  can  be  produced  by  compression  of  the  jugular  vein  in  the 
neck.  In  the  erect  position  there  is  often  enophthalmos.  Sometimes 
dilated  veins  are  visible  in  the  eyelids.  In  a  case  which  we  have  recently 
seen  the  tendency  to  exophthalmos  was  kept  in  check  by  the  wearing  of 
a  bandage  at  night. 

Tumours  and  cysts  of  the  lacrimal  gland  also  occur  in  tlie  orbit  (see 
p.   533). 

Tumours  of  the  Optic  Nerve. — These  are  rare  affections.  They  occur 
at  ail  times  of  life,  but  the  majority  of  the  patients  are  under  twenty  years 
of  age.  The  tumour  usually  commences  about  the  middle  of  the  course 
of  the  nerve,  and  does  not  reach  the  bulbar  end.  The  symptoms  are  : — 
Slowly  increasing  protrusion  of  the  eyeball,  in  a  direction  most  usually 

39 


GlO 


DISEASES    OF    THE   ^YE. 


[CHAJP,    XX. 


Fig,  256. — Tumour  of  the 
Optic  Nerve. 


directly  forwards,  or  forwards  and  outwards   (Fig.   256).     The  motions 

of  the  eyeball  are  not  greatly  restricted,  and  the  centre  of  its  rotation  is 

not  displaced,  owing  to  the  tumour  being  within  the  cone  of  the  orbital 

muscles.      The   proptosis    is   unaccompanied 

fby  pain.  The  sight  becomes  very  defective, 
or  is  quite  lost  at  a  very  early  stage,  from 
interference  with  the  functions  of  the  nerve 
by  the  tumour  or  by  the  optic  neuritis,  or 
optic  atrophy,  to  which  it  gives  rise.  The 
tumour  is  sometimes  very  soft,  so  that  the 
eyeball  can,  as  it  were,  be  pushed  back  into 

it,  and  the  pressure  does  not  cause  pain. 
The  pupil  reacts  consensually.  The  tumour 
may  often  be  felt  by  palpation  in  the  orbit. 
The  patient's  health  does  not  suffer. 

The  diagnosis  between  a  new  growth  of 
the  optic  nerve  and  one  of  its  sheath  can 
hardly  be  made  with  certainty ;  but  the 
existence  of  fairly  good  vision,  while  other 
symptoms  are  as  above  described,  long  after 
the  proptosis  has  appeared,  would  point  to 
the  sheath  as  the  seat.  Such  a  diagnosis  is  important,  for  it  may  be 
possible  to  remove,  by  Kronlein's  operation,  a  tumour  of  the  sheath  of 
the  optic  nerve,  while  jDreserving  not  merely  the  eyeball,  but  good  vision 
as  well. 

These  tumours  are  either  fibro-sarcomata  (fibromatosis),  or,  less  fre- 
quently, endotheliomata,  and  are  usually  intra-dural,  i.e.  encapsuled  by 
the  sheath  of  the  nerve.  Extra-dural  tumours  are  more  rare.  Both 
varieties  are  benign,  in  the  sense  that  they  do  not  lead  to  glandular  en- 
largements or  to  metastases,  and  they  never 
spread  to  the  eyeball  although  the  extra 
dural  tumours  often  surround  the  posterior 
half  of  the  globe  ;  but  in  some  cases  death 
occurs  from  extension  of  the  disease  to  the 
cranial  cavity,  or  from  the  sudden  develop- 
ment of  intracranial  growths,  which  co- 
existed with  the  optic  nerve  tumour.  An 
intracranial  complication  may  occur  many 
years  after  removal  of  the  tumour  of  the 
nerve.  Local  recurrence  is  less  common,  but 
in  one  case  a  recurrence  took  place  in  the 
orbit  twenty-six  years  after  operation. 

Treatment. — To  remove  these  tumours 
three  methods  are  available,  namely: — (1) 
Removal  of  the  eyeball  with  the  tumour  ; 
(2)  Kronlein's  operation,  by  means  of  which 
the  optic  nerve  tumour,  probably  in  the 
majority  of  cases,  may  be  removed  without  the  eyeball ;  and  (3)  Knapp's 
operation — also  for  removal  of  the  tumour  without  the  eyeball.     It  is 


Fig.  257. — The  same 
patient  as  in  Fig.  256  after 
Kronlein's  operation. 


GHAP.  XX.]  THE  ORBIT.  611 


unnecessary  to  describe  the  first  of  these  procedures,  which  follows 
very  much  the  lines  of  an  ordinary  excision  of  the  eyeball,  except  that  the 
optic  nerve  is  divided  as  far  back  in  the  orbit  as  possible.  Kronlein's 
operation  is  described  on  p.  618. 

Knapp's  operation  is  as  follows  : — The  tendon  of  the  internal  rectus  is 
divided  so  as  to  leave  a  portion  adherent  to  the  sclerotic  of  about  5  mm., 
the  cut  end  being  secured  by  a  suture  passed  through  it,  to  prevent  it  from 
retracting  into  tlie  orbit.  The  eyeball  is  then  forcibly  everted  outwards, 
strong  scissors  are  passed  into  the  orbit,  and  the  optic  nerve  is  divided 
as  close  to  the  optic  foramen  as  possible.  The  globe  is  now  further  everted 
outwards,  to  expose  its  posterior  surface  with  the  tumour  attached,  and 
the  latter  is  removed  by  dividing  the  optic  nerve  close  to  the  eyeball. 
Finally,  the  eyeball  is  reposed,  the  cut  ends  of  the  tendon  of  the  muscle 
united,  and  the  opening  in  the  conjunctiva  closed.  A  drawback  to  this 
operation  is,  that  it  is  not  always  possible  to  be  certain  that  the  deep 
portion  of  the  tumour  is  reached  with  the  scissors. 

Lagrange  passes  a  ligature  or  loop  over  the  tumour,  divides  the  nerve 
as  far  back  as  possible,  draws  the  tumour  out,  and  thus  exposes  the  back 
of  the  eyeball,  from  which  the  tumour  is  then  removed.  Fig.  256  repre- 
sents a  case  of  tumour  of  the  optic  nerve  and  Fig.  257  the  same  case  after 
operation  by  Kronlein's  method. 

Implicatiox  of  Neighbourixg  Cavities. — As  regards  the 
question  whether  the  tumour  be  confined  to  the  orbit,  or  involve  one 
or  more  of  the  neighbouring  cavities,  it  may  be  assumed  that  it  is 
confined  to  the  orbit,  unless  there  are  symptoms  or  signs  which  point 
in  the  opposite  direction  ;  and  in  each  case  these  symptoms  and  signs 
ought  to  be  sought  for.  Tumours  may  either  originate  in  one  of 
the  spaces  and  grow  into  the  orbit,  which  is  the  more  common  event ; 
or,  originating  in  the  orbit,  they  may  spread  to  a  neighbouring 
space  ;  and  it  is  often  the  history  or  progress  of  the  case  alone  that 
can  inform  us  which  of  these  events  has  taken  place. 

When  disease  (mucocele,  empyema,  tumour)  of  the  accessory 
sinuses  of  the  nose  involves  the  orbit,  the  symptoms  which  ensue 
may  be  due  to  the  effect  of  the  pressure  exerted  by  the  over-dis- 
tended sinus,  or  to  septic  infection,  or  to  a  combination  of  these. 
The  pressure  effects  are  produced  by  the  formation  of  a  tumour-like 
projection  of  some  portion  of  the  orbital  wall  corresponding  with 
the  position  of  the  affected  sinus.  This  leads  to  displacement  of  the 
eyeball  with  exophthalmos  and  limitation  of  movement,  and  the 
sight  may  be  impaired  or  lost  from  optic  neuritis,  or  from  atrophy 
of  the  optic  nerve.  If  the  sphenoidal,  or  posterior  ethmoidal  sinus 
be  diseased,  impairment  of  vision  in  one  or  both  eyes  may  be  the 
only  symptom  in  the  early  stage.     This  is  due  to  the  fact,  that  the 


G12  DISEASES   OF   THE   EYE.  [cha?.  ^^. 

inner  boundary  of  the  optic  canal  sometimes  forms  a    portion  of 

the  wall  of  these  sinuses,  and  may  be  extremely  thin  on  one  or  both 
sides,  thus  rendering  the  optic  nerve  particularly  vulnerable.  The 
nerve  generally  shows  signs  of  inflammation  or  atrophy,  but  on  the 
other  hand  it  may  be  normal,  as  in  retrobulbar  neuritis  from  other 
causes  (p.  347),  and  the  defect  of  vision  may  only  reveal  itself  as  a 
central  scotoma,  or  as  an  enlargement  of  the  blind  spot. 

If  septic  infection  take  place,  orbital  cellulitis  and  its  conse- 
quences (p.  597)  result.  Infection  is  usually  preceded  by  perforation 
of  the  orbital  wall,  but  it  may  be  carried  into  the  orbit  by  emissary 
veins,  or  through  small  foramina,  or  congenital  dehiscences  in  the 
bony  walls. 

Mucocele  or  empyema  is  sometimes  indicated  by  a  history  of 
influenza,  or  post-nasal  catarrh,  followed  by  purulent  discharge 
from  the  nose.  In  all  cases,  a  careful  examination  of  the  nose 
ought  to  be  made,  aided,  if  necessary,  by  transillumination  and 
radiography.  It  should  be  remembered,  however,  that  empyema 
of  a  sinus,  with  implication  of  the  orbit,  may  sometimes  exist  without 
any  appearance  of  nasal  disease,  if  the  channel  of  exit  from  the  sinus 
be  completely  occluded. 

In  general,  it  may  be  stated  that  inflammation  of  the  frontal  and 
anterior  ethmoidal  sinuses  gives  rise  to  cedema  and  swelling  of  the 
lids,  periostitis  of  the  orbit,  or  peri-dacryocystitis ;  while  disease 
of  the  posterior  ethmoidal  and  sphenoidal  sinuses  is  more  apt  to 
cause  retrobulbar  neuritis,  optic  neuritis  or  atrophy,  or  paralyses 
of  orbital  muscles. 

The  Frontal  Sinus. — This  sinus  begins  to  form  at  about  the 
seventh  year  of  age,  and  continues  to  increase  in  size  from  that 
time  onwards.  Disease  of  this  sinus,  therefore,  is  only  met  with 
in  adults.  It  frequently  extends  to  the  ethmoid,  and  sometimes 
leads  to  maxillary  empyema.  There  may  be  some  redness  and 
swelling  at  the  inner  extremity  of  the  eyebrow,  with  tenderness 
on  percussion,  and  the  patient  sometimes  suffers  from  paroxysmal 
attacks  of  frontal  neuralgia,  often  worse  in  the  morning ;  but  again 
in  this,  as  in  the  case  of  other  sinuses,  the  pain  may  be  diffuse, 
and  not  in  any  way  characteristic.  (Edema  of  the  upper  lid  may 
be  the  only  symptom  of  a  frontal  sinusitis.  We  have  been  con- 
sulted by  patients,  in  one  case  for  an  oedema  of  the  upper  lid,  and 
m  another  for  morning  ptosis,  and  in   both  cases  the  symptoms 


CHAP.    XX.] 


THE   ORBIT. 


613 


were  the  result  of  frontal  sinus  disease.  A  tumour  then  forms  at 
the  upper  and  inner  anpjle  of  the  orbit,  and  displaces  the  eye  down- 
wards and  outwards.  In  some  cases  a  fistula  appears  above  the 
position  of  a  lacrimal  sac,  and  fluid  may  appear  in  the  nostril 
on  syringing  it.  Rarely,  a  frontal  mucocele  may  form  a  sub- 
periosteal collection  in  the  roof  of  the  orbit,  and  point  at  the  outer 
side  of  the  latter.  Osteoma  of  the  frontal  sinus  shows  itself  as  a 
slowly  growing  and  densely  hard  tumour,  almost  free  from  pain, 
situated  along  the  superior  margin  of  the  orbit,  extending  into  the 
latter  and  pushing  the  eyeball  downwards  and  forwards.  It  may 
subsequently  extend  to  the  orbital  plate  of  the  ethmoid,  and  may 
be  mistaken  for  an  exostosis  of  the  orbit.  Bony  growths  originating 
in  the  orbit  may  invade  the  frontal  sinus,  and,  whether  originating 
there  or  in  the  sinus,  are  liable  to  produce  absorption  of  the  tables  of 
the  skull  without  any  cerebral  symptoms  to  indicate  the  occurrence. 
The  Ethmoid  Cells. — Tumours  of  these  cells,  which  encroach 
upon  the  orbit,  are  likewise  most  commonly  either  mucocele  (em- 
pyema) or  osteoma.  Mucocele  of  the  ethmoid  cells  presents  itself 
in  the  orbit,  as  a  smooth  hard  tumour, 
on  the  inner  wall  of  the  orbit,  giviiiu 
rise  to  displacement  of  the  lacrimal 
bone  (with,  perhaps,  a  sense  of  fluctua- 
tion and  crepitation  on  palpation), 
and  pushing  the  eyeball  outwards  and 
forwards.  Epiphora  may  be  an  early 
symptom.  There  is  sometimes  a  feel- 
ing of  pressure  on  the  bridge  of  the 
nose.  Nervous  symptoms,  such  as 
mental  dullness,  hypochondriasis,  etc.. 
may  be  present.  Mucocele  of  the 
ethmoid  cells  encroaching  on  the  orbit 
must  also  be  distinguished  from  a  der- 
moid cyst   (p.  605).     Osteoma  of  the 

ethmoid  appears  in  the  orbit  as  a  hard  round  swelling  at  the 
inner  canthus,  followed  by  a  swelling  of  the  cheek  and  displace- 
ment of  the  eye  outwards  and  forwards.  It  is  apt  also  to  extend 
into  the  nasal  meatus,  displacing  the  septum,  and  pushing  the  hard 
palate  downwards,  so  that  examinations  of  the  nose  and  of  the 
mouth  should  be  made  in  aidjof  the  diagnosis.     Enchondromata 


Fio.  25S. — Anterior  Ethmoi- 
dal Mucocele. 


614  DISEASES   OF   THE  EYE.  [chap.  xx. 

and  fibromata,  too,  sometimes  spring  from  the  ethmoid,  and  extend 
into  the  orbit,  and  malignant  growths  may  be  met  with  here. 

The  Sphenoid  Bone  and  Antrum  of  the  Sphenoid. — Tumours 
originating  here  and  encroaching  upon  the  orbit  are  rare,  and 
the  diagnosis  of  their  origin  in  an  early  stage  may  be  impossible, 
except  by  radiography.  They  may  cause  pain  in  the  occipital 
region,  and,  as  stated  above,  optic  atrophy  may  be  an  early  symptom. 
It  is  said  (Stedman  Bull)  that  an  orbital  tumour  which  soon  causes 
blindness,  commencing  in  the  temporal  side  of  the  field,  and  leaving 
the  fixation  point  unaffected  to  the  last,  while  at  the  same  time  a 
growth  appears  in  the  naso-pharynx,  is  likely  to  be  one  having  its 
origin  in  the  sphenoid  antrum.  Bony  tumours — osteoma,  hypero- 
stosis, and  exostosis — polypi,  and  sarcomata  are  the  growths  most 
frequently  found  to  originate  in  the  sphenoid  antrum. 

The  Maxillary  Antrum. — Tumours  of  the  antrum  sometimes 
push  the  floor  of  the  orbit  upwards,  or  erode  it,  and  grow  into  that 
cavity,  driving  the  eyeball  upwards  and  inwards,  or  upwards  and 
outwards.  The  breadth  of  the  cheek  is  increased,  the  nose  becomes 
pushed  towards  the  opposite  side,  and  the  roof  of  the  mouth  is 
pushed  downwards.  Tumours  of  the  antrum  of  Highmore  some- 
times cause  pain  in  the  teeth,  or  in  the  region  of  distribution  of 
the  infra-orbital  nerve,  and  there  may  be  a  dull  pain  in  the  region 
of  the  antrum.  In  some  cases  there  is  a  discharge  of  pus  or  of 
blood  from  the  nostril.  Empyema  of  the  antrum  may  give  rise  to 
orbital  cellulitis  commencing  at  the  lower  part  of  the  orbit,  with 
swelling  of  the  lower  lid,  and  chemosis  of  the  conjunctiva  below 
the  cornea. 

We  have  seen  two  cases  of  malignant  disease,  one  of  the  maxillary 
antrum,  and  the  other  in  the  nasal  fossa,  in  which  epiphora  was  the 
first  symptom  complained  of  by  the  patient. 

Intracranial  Tumours  do  not  often  invade  the  orbit.  When 
they  do  so  they  originate  in  the  middle  fossa,  and  gain  access 
through  the  sphenoid  fissure  and  optic  foramen.  The  diagnosis  of 
the  origin  of  the  disease  can  only  be  made,  if  cerebral  signs  or 
symptoms,  including  defects  in  the  field  of  vision,  have  existed  prior 
to  any  sign  of  a  new  growth  in  the  orbit.  Tumours  of  the  pituitary 
body  may  encroach  upon  the  orbit  by  way  of  the  sphenoid  fissure,  and 
are  apt  to  be  associated  with  polyuria  and  bitemporal  hemianopsia, 
which  assist  the  diagnosis. 


CHAP.    XX.] 


THE   ORBIT. 


615 


A  more  common  event,  although  not  in  an  early  stage  of  the 
growth,  is  the  extension  of  a  primary  orbital  tumour  to  the  hrain, 
either  along  the  optic  nerve,  through  the  sphenoid  fissure,  or  through 
the  roof  of  the  orbit  by  erosion  of  the  bone.  This  occurrence  is 
usually  indicated  by  the  presence  of  cerebral  symptoms  ;  but  cases 
have  been  met  with  where  no  such  symptoms  existed,  although 
the  orbital  growth  had  encroached  upon  the  anterior  or  middle 
fossa  of  the  skull. 


Shrinking    of    the    Conjunctiva    (Xerophthalmos)    and   of  the   Sub-con- 
junctival  Tissue  of    the  Orbit,  subsequent  to  Enucleation  of  the  Eyeball. — 

111  some  cases  where  the  (>yel)all  lias  l)eeu  excis(nl,  and  in  chie  course 
a  prothesis  fitted,  the  conjunctiva  and  sub-conjunctival  tissues  shrink 
to  such  a  degree,  after  some  months  or  years,  as  to  reduce  the  size  of  the 
orbital  cavity  so  that  the  wearing  of  a  glass  eye  becomes  impossible. 
This  is  especially  liable  to  occur  amongst  those  hospital  patients  who  are 
careless  in  removing  the  prothesis  at  night,  and  in  keeping  the  socket 
thoroughly  clean  at  all  times.  The  attempt  is  then  often  made  to  restore 
the  orbital  cavity,  so  as  to  render  it  possible  to  wear  at  least  a  small 
glass  eye,  by  means  of  skin  grafts,  or  of  mucous  membrane  grafts,  after 
the  method  either  of  Thiersch  or  of  Wolfe.  The  success  attendant  on 
these  procedures  is  usually  a  very  moderate  one,  and  often  not  permanent, 
owing  to  subsequent  renewed  shrinking  of  the  sub-conjunctival  tissue. 

In  these  cases  the  lower  sulcus 
is  the  most  important  part  of  the 
cavity,  and  if  it  can  be  made 
sufficiently  deep,  a  small  artificial 
eye  will  be  retained.  This  can  be 
done  in  certain  cases  by  Maxwell's 
method  (Fig.  259). 

An  incision  is  made  in  the 
floor  of  the  socket,  and  carried 
downwards  behind  the  lower  lid. 
A  semi-lunar  flap,  about  8  mm.  in 
width  at  its  widest  part,  is  marked 
out  on  the  skin  of  the  lid,  its 
upper  concave  border  being  about 
5  mm.  below  the  palpebral  margin. 
The     incision     along     the     upper 

border  of  the  flap  is  made  to  communicate  with  the  bottom  of  the  wound 
in  the  socket.  The  flap  is  now  dissected  up  from  the  subcutaneous  tissue, 
except  an  area  represented  by  the  dotted  line  in  Fig.  259.  The  two  ends 
of  the  flap  {a'  and  h')  are  passed  through  the  opening  into  the  socket,  and 
sutured  to  each  end  of  the  socket  incision  (a  and  h) ;  and  the  borders  A' 
and  B' ,  being  also  passed  through,  are  sutured  to  ^  and  B  respectively. 
The  space  on  the  cheek  is  closed,  and  the  operation  completed  by  inserting 
into  the  socket  a  temporary  glass  eye  or  shell.     This  should  be  as  nearly 


Fig.  259. 


616  DISEASES    OF   THE   EYE.  [chap.  xx. 

as  possible  of  the  size  and  shape  of  the  eye  to  be  ultimately  worn  ;  it 
prevents  the  new  sulcus  from  being  obliterated  by  contraction,  and  gives 
it  a  suitable  shape.  It  cannot  safely  be  taken  out  for  at  least  a  week,  as 
the  skin  incision  might  perhaps  be  opened  in  so  doing.  If  there  be  secretion, 
the  space  behind  may  be  flushed  out  by  a  lacrimal  syringe  armed  with  a 
fine  curved  nozzle,  which  can  be  introduced  under  the  edge  of  the  eye  at 
the  inner  or  outer  canthus.  A  glass  shell  with  a  hole  in  front  is  preferable 
to  a  glass  eye,  for  it  allows  a  syringe  to  be  more  easily  used,  and,  being 
transparent,  a  view  of  the  parts  behind  can  be  obtained. 

To  obtain  a  good  result  the  following  points  should  be  attended  to  : 
(1)  Make  the  incision  in  the  socket  as  long  as  the  space  will  permit,  and 
see  that  this  length  is  maintained  throughout  its  entire  depth.  (2)  Make 
the  skin  flap  considerably  longer  than  the  incision  in  the  socket.  (3) 
When  dissecting  up  the  skin  flap  leave  undisturbed  a  portion  (dotted 
line  in  figure)  equal  in  length  to  the  socket  incision.  This  subsequently 
forms  the  fornix,  or  sulcus.  If  a  shorter  portion  be  left,  the  sulcus  is 
apt  to  become  V-shaped,  which  would  require  a  specially  made  glass  eye. 
(4)  When  closing  the  space  on  the  cheek,  as  the  lower  border  is  longer 
than  the  upper,  great  care  should  be  taken  to  equably  distribute  the  excess, 
so  as  to  avoid  puckering.  When  this  has  been  neatly  done,  the  line  upon 
the  face  becomes  quite  invisible  after  a  few  months. 

In  none  of  the  cases,  so  far,  has  it  been  necessary  to  make  a  sulcus 
above.  The  same  operation  could,  however,  be  performed  on  the  upper 
lid,  provided  that,  after  dissecting  up  both  the  borders  of  the  skin  flap, 
the  tendon  of  the  levator  were  secured  with  one  or  two  sutures  before 
dividing  it.  After  the  skin  flap  is  in  its  new  position,  the  cut  end  of  the 
levator  could  be  attached  to  the  tarsus.  In  closing  the  skin  wound,  the 
ends  of  these  deep  sutures  should  be  allowed  to  project  outwards,  so 
that  they  may  be  pulled  out  when  they  ultimately  become  loose.  If  it 
were  possible  to  obtain  thoroughly  aseptic  catgut,  the  ends  of  the  sutures 
might  be  cut  short  and  buried. 

In  addition  to  providing  a  sulcus,  the  operation  adds  half  the  width 
of  the  flap — viz.  4  mm.  to  the  vertical  diameter  of  the  socket. 

Transplantation  of  skin  flaps  without  pedicle. — If  there  be  much 
cicatricial  contraction,  the  above  operation  is  not  sufficient,  and  it  is 
better  to  transplant  skin  flaps  (dermal  or  epidermal)  from  the  arm  to 
the  spaces  made  by  freeing  the  lids.  The  dissection  of  the  lids  should 
be  deep,  and  all  fibrous  bands  should  be  thoroughly  divided.  Either  of 
two  plans  may  be  adopted.  In  the  first,  the  conjunctiva  is  dissected 
from  the  lid  margin,  and  the  island  of  mucous  membrane  thus  formed 
furnishes  the  covering  for  the  central,  or  apical  portion  of  the  new 
socket,  while  the  lids  and  artificially  made  fornices  are  clothed  with 
the  flaps  from  the  arm.  Or,  secondly,  the  conjunctiva  may  be  divided 
horizontally  in  the  centre,  and  dissected  up,  except  where  it  covers  the 
tarsus,  and  the  skin  flaps  may  be  used  to  cover  the  back  of  the  orbit, 
and  posterior  surfaces  of  the  newly  made  fornices. 

The  great  difficulty  in  all  these  operations  consists  in  keeping  the  flaps 
in  close  apposition  with  the  soft  and  yielding  tissues  of  the  orbit,  otherwise 
the  flaps  shrink,  and  therefore  it  is  necessary  to  support  and  retain  them 


CHAP.    XX.] 


THE    ORBIT. 


617 


in  position,  with  some  solid  material,  such  as  gntta-percha  or  lead,  which 
can  be  cut  and  mouldod  to  fit  the  orbital  cavity  and  fornices.  The  flaps 
may,  if  necessary,  be  wrapped  round  the  artificial  support,  raw  surface 
outwards,  and  fastened  to  it  with  sutures.  After  the  insertion  of  the  flap 
and  shell,  the  edges  of  the  lids  are  temporarily  sewn  together,  and  opened 
again  in  about  a  week. 

Griinert  adopts  the  first  method,  and  then  divides  the  outer  canthus 
and  frees  both  lids,  so  that  they  can  be  fully  everted.  The  lids  are  then 
well  everted,  and  sutured  respectively  to  the  brow  and  cheek.  The  skin 
flaps  are  thus  easily  applied,  and  good  contact  can  be  ensured  by  pressure 
of  a  bandage.  After  a  couple  of  weeks  the  lids  can  be  replaced,  and  the 
outer  commissure  re-united. 

Weeks'  operation  is  a  good  one.  The  object  of  it  is  to  obtain  a  fixed 
attachment  for  the  flap  by  suturing  it  to  the  periosteal  tissue  of  the 
margin  of  the  orbit  and  so  prevent  shrinking.  The  external  canthus  is 
divided,  an  incision  is  next  made 
parallel  to  the  edge  of  the  lid,  on 
the  conjunctival  surface  3  mm.  from 
the  lid  margin,  the  eyelid  is  then  dis- 
sected from  the  orbital  tissues  so  that 
the  anterior  layer  contains  only  skin, 
orbicularis,  and  tarsus.  A  groove  is 
cut  reaching  down  to  the  orbital  mar- 
gin and  extending  from  the  inner 
canthus  to  the  outer  commissure.  An 
oval  skin-flap  is  taken  from  the  inner 
surface  of  the  arm,  one-third  larger 
than  the  raw  surfaces  to  be  covered, 
and  is  freed  from  fat  and  subcutaneous 
tissue.  The  flap  having  been  folded 
with  the  epithelial  surfaces  in  appo- 
sition, three  double  sutures  are  passed 
through  the  bottom  of  the  fold.  The 
flap  is  wrapped  in  a  piece  of  sterile 
moistened  gauze  and  laid  on  the 
patient's  forehead.  The  cul-de-sac  is 
examined    and  cleared  of    any   loose 

tags.  The  double  sutures  in  the  flap  are  now  passed  through  the  perios- 
teal tissue  at  the  bottom  of  the  groove  or  cul-de-sac,  and  are  tied  on  the 
cheek  over  small  rolls  of  gauze  (Fig.  260).  A  suitably-fashioned  rubber  plate 
is  inserted  into  the  cul-de-sac.  The  anterior  and  posterior  margins  of  the 
flap  are  sutured  to  the  lid  margin  and  to  the  orbital  tissues  respectively. 

A  sterilised  dressing  and  bandage  are  applied  and  not  removed  for 
four  days  unless  unfavourable  symptoms  arise.  Tlie  plate  should  remain 
in  for  ten  days  or  a  fortnight,  and  then  should  be  replaced  by  an 
artificial  eye.  The  periosteal  sutures  should  not  be  disturbed  until  they 
become  somewhat  loosened — usually  in  about  six  to  ten  days.  The 
artificial  eye  must  be  kept  in  situ  until  the  shrinkage  has  ceased,  and 
must  only  be  removed  for  cleaning  every  four  to  seven  days. 


Fig,  260. — Weeks'  operation, 
showing  flap  in  position.  1, 
orbital  tissue  ;  2.  flap  ;  3.  lid  ; 
4,  periosteal  tissue  ;  5.  sutures  ; 
6.  bone  of  orbit. 


618  /    DISEASES   OF    THE   EYE.  [chap.   xx. 

Weeks  uses,  for  the  plate,  dentist's  base-plate  gutta-percha,  which 
can  be  softened  by  dipping  in  hot  water,  and  can  then  be  cut  to  any  size 
with  scissors,  while  the  edges  can  be  made  perfectly  smooth  with  a  hot 
strabismus  hook  smeared  with  vaseline,  to  prevent  sticking.  Before 
insertion  the  plate  should  be  sterilised  by  washing  and  treating  with 
alcohol  and  bichloride  solution,  and  lubricated  with  bichloride  vaseline 
1-5,000.     It  should  fit  snugly  without  undue  pressure. 

Temporary  Resection  of  the  Outer  Wall  of  the  Orbit  (Krbn- 
lein's  Operation) . — This  operation  was  devised  by  the  late  Professor 
Kronlein,  of  Ziirich.  It  is  well  suited  for  the  removal  of  tumours  of 
the  optic  nerve,  and  other  new  growths  and  cysts  in  the  posterior 
part  of  the  orbit,  as  well  as  foreign  bodies,  without  sacrificing  the 
eye-ball,  or  perhaps  even  the  sight.  It  may  also  be  employed  to 
reach  purulent  foci  in  the  orbit,  and  has  been  used  to  remove  some 
of  the  retrobulbar  fat  in  cases  of  exophthalmic  goitre. 

The  eyebrow  and  the  scalp  in  the  temporal  region  are  shaved, 
and  the  skin  of  the  whole  region  of  the  operation  is  rendered  aseptic. 

The  First  Stage  of  the  operation  consists  in  making  a  curved 
incision  on  the  temple  through  the  skin  and  soft  parts.  This  incision 
commences  on  the  temporal  ridge,  at  a  point  w^here  the  latter  would 
be  intersected  by  a  horizontal  line  running  1  cm.  above  the  supra- 
orbital margin.  The  middle  point,  or  apex,  of  the  incision  lies  in 
the  centre  of  a  horizontal  line,  which  unites  the  external  canthus  with 
the  outer  orbital  margin.  The  end  of  the  incision  lies  on  the  zygoma, 
in  the  centre  of  a  horizontal  line  uniting  the  external  canthus  with 
the  tragus.  The  length  of  the  incision  in  adults  is  6  to  7  cm.,  and 
the  direct  distance  between  its  two  ends  is  about  5  cm.  Smaller 
incisions  are  inconvenient.  In  that  portion  of  the  incision  which 
runs  along  the  margin  of  the  orbit  it  goes  to  the  bone,  through  the 
periosteum. 

The  Second  Stage  consists  in  raising  the  periosteum  from  the 
inner  surface  of  the  outer  wall  of  the  orbit  with  a  slightly  curved  and 
somewhat  pointed  elevator,  which  is  introduced  at  the  exposed 
outer  orbital  margin.  The  periosteum  is  separated  upwards  as  far 
as  1  cm.  above  the  fronto-malar  suture,  downwards  as  far  as  the 
spheno-maxillary  fissure,  and  posteriorly  until  well  behind  the 
spheno-zygomatic  suture.  This  proceeding  is  not  difficult,  as  the 
periosteum  is  closely  adherent  along  the  orbital  margin  only,  and 
at  the  sutures.     The  point  of  the  elevator  is  now  passed  directly 


CHAP.  XX.]  THE    ORBIT.  619 


downwards,  and  carefully  introduced  into  the  spheno-maxillary 
fissure  a  few  millimetres  behind  the  spheno-zygomatic  suture.  The 
handle  of  the  instrument  is  then  turned  over  "gently  towards  the 
nose,  thus  pressing  the  periosteum  and  all  the  contents  of  the  orbit 
somewhat  inwards,  and  exposing  the  bared  inner  surface  of  the  outer 
orbital  wall.  The  object  of  passing  the  point  of  the  elevator  into 
the  spheno-maxillary  fissure — where  it  remains  during  the  next  stage 
of  the  operation — is  to  fix  the  point  towards  which  the  osseous  in- 
cisions are  to  be  made  to  converge.  Some  surgeons  prefer  to  omit 
this  act,  and  the  proximity  of  the  infra-orbital  nerve,  and  of  the 
infra-orbital  vessels,  must  be  borne  in  mind. 

The  Third  Stage  includes  the  resection  of  the  bony  wall  by  three 
incisions,  two  horizontal  and  one  oblique.  The  upper  horizontal 
bony  incision  is  made  with  a  thin,  sharp  chisel,  which  should  divide 
the  external  angular  process  of  the  frontal  bone  close  to  its  base. 
The  soft  parts  having  been  previously  drawn  aside,  the  periosteum 
over  the  seat  of  the  proposed  bony  incision  is  divided,  and  the 
orbital  periosteum  and  the  lacrimal  gland  are  drawn  aside. 

The  oblique  bony  incision  passes  from  the  deepest  part  of  the 
previous  incision  downwards  and  backwards  behind  the  spheno- 
maxillary suture,  through  the  greater  wing  of  the  sphenoid  bone,  to 
a  point  about  1  cm.  behind  the  anterior  end  of  the  spheno-maxillary 
fissure,  where  the  point  of  the  elevator  has  been  kept  all  through. 

The  lower  horizontal  bony  incision  divides  the  frontal  process 
of  the  malar  bone  close  to  its  base,  the  soft  parts  having  been 
drawn  aside,  and  the  periosteum  divided.  The  incision  ends  at 
the  anterior  extremity  of  the  spheno-maxillary  fissure. 

In  making  the  bony  incisions  there  is  the  danger  of  splintering  to 
be  contended  with,  and  in  the  oblique  incision  there  is  some  danger 
of  luxating  the  spheno-maxillary  suture.  The  chisel  must  be  very 
sharp  and  thin,  and  it  is  well  to  apply  its  corner  rather  than  its  full 
edge  to  the  bone,  while  only  light  taps  with  the  mallet  are  used.  It 
is  important  to  make  the  bony  incisions  in  the  above  order ;  or,  at 
any  rate,  the  oblique  incision  should  not  be  the  last  to  be  made,  for, 
if  it  be,  the  thin  outer  wall  of  the  orbit  is  liable  to  become  severely 
splintered  during  the  chiselling  of  the  second  bony  process. 

The  lower  bony  incision  can  also  be  made  (Magitot  and  Landrieu) 
with  a  Gigli  saw  passed  with  a  cannula  from  the  temporal  fossa 
through  the  spheno-maxillary  fissure,  and  the  upper  one  may  be 


620  DISEASES   OF   THE  EYE.  [chap.  xx. 


facilitated  by  first  grooving  the  bone  witb  a  small  saw,  before  using 
the  chisel. 

The  Fourth  Stage  is  the  turning  backwards  of  the  flap  of  bone  and 
soft  parts,  and  the  exposure  of  the  interior  of  the  orbit.  After  the 
flap  has  been  turned  well  back,  the  separated  periosteum  is  divided 
with  blunt-pointed  scissors,  from  before  backwards.  It  is  some- 
times necessary,  in  order  to  reach  the  focus  of  disease,  to  divide  the 
tendon  of  the  external  rectus  near  its  sclerotic  insertion,  and  possibly 
other  orbital  muscles  must  be  severed  ;  but  this  should  be  avoided, 
if  possible. 

"When  all  manipulations  required  in  the  orbit  have  been  com- 
pleted, any  muscles  which  may  have  been  divided  are  sutured  to 
their  insertions,  the  periosteum  is  replaced  in  its  normal  position, 
the  flap  of  bone  and  soft  parts  turned  forwards  into  its  place,  and 
secured  there  by  a  few  catgut  sutures  through  the  periosteum.  A 
drain  is  then  placed  in  the  lower  part  of  the  wound,  and  the  rest  of 
the  wound  is  accurately  closed  with  fine  silk  sutures,  and  an  aseptic 
dressing  and  bandage  applied.  The  catgut  sutures  through  the 
periosteum,  and  the  drain,  are  regarded  by  several  operators  as  un- 
necessary. 

We  have  performed  the  operation  for  tumours  of  the  optic  nerve 
(Fig.  257),  and  other  tumours  of  the  orbit,  for  a  mucocele  of  the 
frontal  sinus  which  extended  out  under  the  roof  of  the  orbit,  and  for 
diagnostic  purposes  in  a  case  of  pulsating  exophthalmos,  and  have 
found  it  very  satisfactory.  The  resulting  scar  is  not  disfiguring 
(Fig.  257). 

Exophthalmic  Goitre  (Graves'  Disease,  Basedow's  Disease). 

Symptoms. — The  three  cardinal  symptoms  of  this  disease  are  :  in- 
creased rapidity  of  the  heart's  action,  which  may  reach  two  hundred 
beats  per  minute  ;  tumefaction  of  the  thyroid  gland ;  and  exoph- 
thalmos, which  is  nearly  always  bilateral.  Of  these  the  cardiac 
symptom  is  the  most  constant,  and  usually  the  first  to  appear ; 
either,  or  both  of  the  others,  may  be  wanting.  There  is  often  also 
great  emaciation  (Fig.  261),  with  outbursts  of  sweating  and  diarrhoea. 
A  venous  murmur  may  be  heard  in  the  neck,  and  a  thrill  can  often 
be  felt  over  the  enlarged  thyroid.  In  females  there  is  very  commonly 
irregularity  or  suppression  of  menstruation. 

The  disease,  which  is  much  commoner  in  women  than  in  men, 
has  been  observed  at  all  ages,  but  is  most  common  in  early  adult  life. 


CHAt».    XX.] 


THE)    ORBIT. 


G2l 


Von  Grsefe's  Sign  is  a  very  early,  tolerably  constant,  and  almost 
pathognomonic  one  :  it  consists  in  an  impairment  of  the  consensual 
movement  of  the  upper  lid  in  association  with  the  eyeball.  When, 
in  the  normal  condition,  the  globe  is  rolled  downwards,  the  upper 
eyelid  falls,  and  thus  its  margin  is  kept  throughout  in  a  constant 
relation  to  the  upper  margin  of  the  cornea.  In  Graves'  Disease  the 
descent  of  the  upper  lid  does  not  take 
place,  or  does  so  imperfectly  ;  and, 
consequently,  when  the  patient  looks 
down,  a  zone  of  sclerotic  becomes 
visible  between  the  margin  of  the  lid 
and  the  cornea.  This  symptom  is 
often  present  prior  to  any  exophthal- 
mos, and  hence  its  great  diagnostic 
value.  It  may  also  continue  after 
the  latter  disappears — although  it  is 
perhaps  more  common  for  it  to  dis- 
appear before  the  proptosis — and  it  is 
not  seen,  or  but  very  rarely  so,  in 
protrusion  of  the  globe  from  other 
causes.       But    the    sign    is    not    so 

absolutely  pathognomonic  as  it  was  held  to  be  by  von  Graefe  ;  for 
it  may  be  absent  in  Graves'  Disease,  although  very  rarely  so,  in 
the  early  stages,  and  it  is  sometimes  present  in  other  diseased  states, 
and  even  in  health. 

Stellwag's  Sign,  namely,  incompleteness  and  diminished  frequency 
of  the  act  of  involuntary  nictitation,  is  also  very  constant.  This  act 
occurs  sometimes  only  once  in  a  minute  :  or  several  rapid  nictita- 
tions take  place,  and  then  a  lengthened  pause.  The  nictitation  each 
time  is  incomplete,  the  margins  of  the  lid  not  being  brought  together. 
The  result  may  be  that  the  lower  third  of  the  cornea  becomes  covered 
with  pannus  vessels,  owing  to  the  constant  exposure  ;  for  even 
during  sleep  the  eyelids  remain  partially  open. 

Dalrymple's  Sign  consists  in  an  abnormal  widening  of  the  palpe- 
bral aperture,  due  to  retraction  of  the  upper  eyelid.  It  is  this  gaping 
of  the  eyelids,  with  the  resulting  exposure  of  the  sclerotic  above  the 
cornea,  which  gives  the  characteristic  staring  aspect  to  the  patient. 

1  We  are  indebted  to  Dr.  Martin  Dempsey  for  the  photograph  of  this 
patient. 


Fig.  261. — Exophthalmic 
goitre,  accompanied  with  great 
emaciation,  in  a  young  lad.^ 


622  Diseases  of  the  eye.  [chap.  ^k. 


The  sign  is  often  erroneously  attributed  to  Stellwag,  or  is  included 
in  his  sign.i 

Insufficiency  of  convergence  has  been  observed  by  Moebius  and 
is  called  Moebius'  Sign,  but  it  is  not  always  present  and  is,  we  think, 
merely  indicative  of  general  nervous  debility,  and  not  of  import- 
ance as  a  sign  of  Graves'  Disease. 

Probably  the  first  three  '  signs '  are  due  to  the  one  cause — 
namely,  loss  of  power  in  the  orbicularis,  rather  than  over-action  of 
the  levator. 

Spontaneous  pulsation  in  the  retinal  arteries  is  said  to  occur,  but 
it  is  exceptional.  The  vision — unless  when  corneal  complications 
supervene — and  the  condition  of  the  pupil  are  unaffected  by  the 
disease.  The  pupils  and  field  of  vision  are  also  normal.  In  some 
cases  there  is  an  increased  flow  of  tears,  but  most  of  the  patients 
complain  of  a  dryness  of  the  eyeballs.  The  sensibility  of  the  cornea 
is  diminished.  Ulcers  of  the  cornea  are  not  common,  but  are  said 
(von  Graefe)  to  be  more  frequent  in  men  than  in  women.  The  ex- 
posure of  the  eye  and  dryness  of  the  cornea  are  the  chief  causes  of 
ulceration,  when  it  occurs  ;  we  have  seen  a  case  in  which  both  eyes 
were  lost  from  suppuration  of  the  cornea  from  exposure. 

The  patients  are  often  hysterical ;  and  even  marked  psychical 
disturbances  have  been  noted,  such  as  a  peculiar  and  unnatural 
gaiety,  rapidity  of  speech,  and  great  irritability ;  or,  on  the  other 
hand,  extreme  depression,  and  even  attempts  at  suicide  have  been 
observed.  Also  loss  of  memory  and  inability  to  make  a  mental 
effort.  The  motions  of  the  eyeball  have  in  some  cases  been  defective 
— a  fact  for  which  the  exophthalmos  does  not  account.  Well- 
marked  muscular  tremors,  affecting  also  the  orbicularis  oculi,  are 
frequently  present,  and  Trousseau's  Cerebral  Macula  is  often  seen. 

The  Progress  of  the  Disease  is,  as  a  rule,  very  chronic,  extending 
over  months  or  years,  but  liable  to  fluctuations  in  the  intensity  of 
its  symptoms.  A  few  cases  have  been  recorded  in  which  it  became 
fully  developed  in  the  course  of  some  hours  or  days.     After  a  length- 

1  Other  conditions  which  produce  widening  of  the  palpebral  aperture 
or  '  Staring  Eye,'  are: — (1)  Orbital  Tumour  (mechanically).  (2)  Stimu- 
lation of  the  Cervical  Sympathetic.  (3)  Cocaine  (in  slight  degree,  prob- 
ably by  reason  of  2).  (4)  Women  after  child-birth  (hysteria).  (5)  In 
tetanus  (spasm  of  occipito-frontalis).  (6)  In  complete  amaurosis,  and 
(7)  it  is  seen  rarely  in  some  healthy  individuals  on  fixation  and  convergence 
for  a  near  object. 


ChAi^.  XX.]  THE   ORBlf.  (l2:i 

ened  period,  and  iiuiiiy  lluctuutioiis,  the  symptoms  usually  slowly 
disappear.  Occasionally  a  slight  permanent  s\vellin«i  of  the  thyroid 
may  remain,  and  very  often  more  or  less  exophthalmos.  About 
12  per  cent,  of  the  cases  go  from  bad  to  worse,  and  end  fatally  from 
general  exhaustion,  organic  disease  of  the  heart  which  may  have 
come  on,  cerebral  apoplexy,  hfiemorrhage  from  the  bowels,  or  gan- 
grene of  the  extremities. 

Causes. — Anaemia  and  clilorosis  are  general  conditions  very 
often  present,  as  are,  also,  irregularities  of  menstruation  ;  but  it  is 
probable  that  the  latter  should  be  regarded  rather  as  a  concomitant 
symptom  than  as  a  cause.  Severe  illnesses  are  recorded  as  having 
gone  before  the  onset  in  many  cases,  and  also  excessive  bodily  or 
mental  efforts.  Great  sexual  excitement  has  been  known  to  be 
followed  by  Graves'  Disease,  and  depressing  psychical  causes  are 
not  unfrequent  forerunners  of  it.  In  many  instances,  how^ever,  the 
patients  have  been  perfectly  healthy,  and  no  cause  could  be  assigned. 
The  Enlargement  of  the  Thyroid  is  due  in  the  first  instance  to 
dilatation  of  its  vessels  ;  but  in  a  late  stage  hypertrophy  of  the 
gland  tissue  may  be  produced,  and  increase  of  its  connective  tissue, 
and  even  cystic  degeneration.  The  Exophthalmos  is  due  to  hyper- 
emia of  the  retro-bulbar  orbital  tissues,  as  is  demonstrated  by  a 
vascular  bruit  often  present,  and  the  fact  that  steady  pressure  on 
the  globe  diminishes  the  protrusion.  Hypertrophy  of  the  orbital 
fat  may  be  found  ])ost  mortem,  but  it  is,  doubtless,  secondary  to  the 
hyper^emia. 

With  regard  to  the  nature  of  the  disease,  very  many  theories 
have,  from  time  to  time,  been  put  forward.  It  is  most  probable 
that  the  disease  is  due  to  the  excessive  or  altered  secretion  of  the 
thyroid  gland. 

Treatment. — A  principal  part  of  this  consists  in  the  careful 
regulation  of  the  patient's  general  health  and  functions.  Freedom 
from  mental  anxiety  and  excitement,  regular  hours,  much  resting 
with  moderate  exercise  on  the  flat,  and  change  of  air  are  the  most 
important  items. 

The  fluctuations,  which  occur  in  the  intensity  of  the  symptoms, 
render  it  difficult  to  arrive  at  definite  conclusions  w^ith  regard  to  the 
efficacy  of  remedies,  a  vast  number  of  which  have  been  tried  and 
lauded  from  time  to  time.  In  mild  forms  of  the  affection,  and 
especially  if  the  anaemia  be  well  marked,  iron  internally  is  beneficial, 


624  DISEASES   OF   THE  EYE.  [chA?.  55:x. 

but  in  severe  cases  it  has  the  opposite  effect.  Quinine  in  moderate 
closes  has  been  employed  with  benefit  in  some  cases.  Trousseau 
recommended  digitalis  in  large  doses,  but  its  effect  must  be  watched. 
The  beneficial  action  of  iodide  of  potassium  in  ordinary  goitre  has 
suggested  its  use  in  this  disease  ;  but  under  its  influence  the  symp- 
toms are  sometimes  aggravated,  and  it  is  doubtful  whether  they 
are  ever  relieved  by  it.  Aconite  has  been  praised  highly,  and  so  has 
belladonna.  Ergotin  internally  has  been  tried,  and  with  advantage 
in  some  instances.  Sattler  warmly  recommends  a  well-regulated 
hydropathic  treatment,  when  the  patient  is  not  too  excitable. 
Paroxysms  of  cardiac  palpitations,  etc.,  are  best  combated  by  ice 
applied  to  the  head,  heart,  and  goitre.  The  sympathetic  theory 
has  induced  the  trial  of  a  galvanic  treatment  of  the  cervical  sym- 
pathetic. Thyroid  extract  has  proved  beneficial  in  some  cases,  also 
antithyroidin  and  the  milk  of  thyroidectomised  goats. 

Gauthier  recommends  antipyrin  before  everything  else.  Ex- 
tract of  the  thymus  gland  has  been  occasionally  employed,  and 
with  encouraging  results. 

Partial  extirpation  of  the  thyroid  has  been  performed  in  recent 
years  with  success  in  some  cases. 

The  great  number  of  remedies  which  have  been  proposed  for  the 
disease  demonstrates  its  intractable  nature.  Yet  a  considerable 
proportion  of  the  cases  do  undergo  cure,  in  so  far  as  quieting  of  the 
heart's  action,  and  reduction,  or,  possibly  sometimes,  complete 
disappearance,  of  the  goitre  and  exophthalmos,  are  concerned.  It 
is  common,  however,  even  in  the  best  recoveries,  to  see  some  ex- 
ophthalmos remain  permanently. 

In  cases  where  the  exophthalmos  is  so  great  that  the  cornea  is 
exposed  even  during  sleep,  it  is  desirable  to  perform  tarsoraphy  (p. 
561)  ;  and  the  same  operation  is  indicated  when,  the  disease  having 
subsided,  the  exophthalmos  still  remains  to  a  degree  which  gives 
the  patient  a  disagreeable  expression. 


APPENDIX. 

REGULATIONS  AS  TO  DEFECTS  OF  VISION  WHICH  DISQUALIFY 
CANDIDATES  FOR  ADMISSION  INTO  THE  CIVIL,  NAVAL, 
AND  xMILITARY  GOVERNMENT  SERVICES,  THE  ROYAL 
IRISH  CONSTABULARY,  AND  THE  MERCANTILE  MARINE. 

Candidates  for  Commissions  in  the  Army  (including  the  Royal  Army 
Medical  Corps)  and  Special  Reserve. — Squint,  or  any  morbid  condition 
of  the  eyes  or  of  the  lids  of  either  eye  liable  to  the  risk  of  aggravation  or 
recurrence,  will  cause  the  rejection  of  the  candidate. 

The  examination  for  determining  the  acuteness  of  vision  includes  two 
tests :  one  for  distant,  the  other  for  near  vision.  The  Army  Test  Types 
will  be  used  for  the  test  for  distant  vision,  without  glasses  except  where 
otherwise  stated  below,  at  a  distance  of  20  feet :  and  Snellen's  Optotypi 
for  the  test  for  near  vision,  without  glasses,  at  any  distance  selected  by  the 
candidate.  Each  eye  will  be  examined  separately,  and  the  lids  must  be 
kept  wide  open  during  the  test.  The  candidate  must  be  able  to  read  the 
tests  without  hesitation  in  ordinary  daylight. 

A  candidate  possessing  acuteness  of  vision,  according  to  one  of  the 
standards  herein  laid  down,  will  not  be  rejected  on  account  of  an  error 
of  refraction,  provided  that  the  error  of  refraction,  in  the  following  cases, 
does  not  exceed  the  limits  mentioned,  viz.  :  (a)  in  the  case  of  myopia,  that 
the  error  of  refraction  does  not  exceed  2*5  D  ;  (6)  that  any  correction  for 
astigmatism  does  not  exceed  2'5  D  ;  and,  in  the  case  of  myopic  astigmatism, 
that  the  total  error  of  refraction  does  not  exceed  2*5  D. 

Subject  to  the  foregoing  conditions,  the  standards  of  the  minimum 
acuteness  of  vision  with  which  a  candidate  will  be  accepted  are  as  follows  : — 

Standard  I. 

Right  eye.  Left  eye. 

Distant  vision.— V  =  6/6.  V  =  6/6. 

Near  vision. — Reads  0,  6.  Reads  0,  6. 

40  625 


626 


APPENDIX. 


Standard  II. 


Better  eye. 
Distant  vision. — V  =  6/6. 

Near  vision. — Reads  0,  6. 


Worse  eye. 

V,  without  glasses,  =  not  below 
6/60  ;  and,  after  correction  with 
glasses,  =  not  below  6/24. 

Reads  1. 


Standard  III. 


Better  eye. 

Distant  vision. — V,  without  glasses 
=  not  below  6/24  ;  and,  after 
correction  with  glasses,  =  not 
below  6/6. 

Near  vision. — Reads  0,  8. 


Worse  eye. 

V,  without  glasses,  =  not  below 
6/24  ;  and,  after  correction  with 
glasses,   =  not  below  6/12. 

Reads  1. 


In  Standard  III.,  the  standard  for  the  test  for  distant  vision,  without 
glasses,  for  officers  of  the  Special  Reserve,  will  be  not  below  6/36. 

Inability  to  distinguish  the  principal  colours  will  not  be  regarded  as  a 
cause  for  rejection,  but  the  fact  will  be  noted  in  the  report  and  the  candi- 
date will  be  informed. 

The  degree  of  acuteness  of  vision  of  all  candidates  for  commissions 
(including  preliminary  examinations)  will  be  entered  in  their  reports  in 
the  following  manner  : — 


Q  i^  .     4.      /Right  eye  V  =    Reads 

Sufficient       T  7^  T/  r»     j 

(Left  eye  V  =    Reads 

^  ,      .  fRight  eye  V  =    Reads 

Defective     ( Left  eye  V=    Reads 


No  relaxation  of  the  standard  of  vision  will  ever  be  allowed. 
Recruits  for  all  Arms  of  theMilitary  Service.— In  examininga  recruit's 
vision  he  will  be  placed  with  his  back  to  the  light,  and  his  visual  acuteness 
will  be  tested  by  means  of  test  types  placed,  in  ordinary  daylight,  at  a 
distance  of  six  metres  (20  English  feet)  from  the  recruit. 
Each  eye  will  be  tested  separately  : — 

(a)  If  a  recruit  can  read  D  =  24  at  20  feet,  or  better,  with  each  eye 
without  glasses,  he  will  be  considered  "  FIT." 

(6)  If  he  can  read  D  =  6  at  the  same  distance  with  one  eye,  without 
glasses,  and  not  less  than  D  =  36  with  the  other  eye,  without  glasses^ 
he  will  be  considered  "FIT." 


APPENDIX.  627 

The  foregoing  is  the  standard  test  of  vision  for  all  arms  of  the  service, 
with  the  exception  of  tlie  Cori)s  of  Army  Schoolmasters,  for  which  a  candi- 
date will  be  accepted  if  tlie  examining  medical  officer  is  satisfied  that  his 
vision,  with  or  without  glasses,  is  good. 

The  visual  acuity  of  each  eye  in  the  case  of  approved  recruits  will  be 
entered  on  the  medical  history  sheet. 

The  Royal  Navy.— Candidates  for  Naval  Cadetships  must  possess  full 
normal  vision  (Emmetropia,  and  V  =  6/6)  as  determined  by  Snellen's 
tests,  each  eye  being  separately  examined. 

For  candidates  for  other  branches  of  the  Royal  Navy,  full  normal 
vision  is  not  required,  but  any  defect  of  vision  must  be  due  to  errors  of 
refraction  which  can  be  corrected  to  normal  by  glasses,  and  vision  without 
glasses  must  in  any  case  be  not  less  than  6/60  with  each  eye,  and  the 
candidate  must  also  be  able  to  read  D  =  0,  6  of  Snellen's  test  types.  A 
candidate  is  disqualified  by  any  imjoerfection  of  his  colour  sense. 

Strabismus,  any  defective  action  of  the  orbital  muscles,  any  derange- 
ment of  the  lacrimal  apparatus,  or  any  chronic  disease  of  the  eyes  or  eye- 
lids disqualifies. 

For  candidates  for  the  seaman  class  (including  boys  and  youths), 
marines  (excluding  marine  bandsmen),  armourer  ratings,  engine-room 
artificers,  electricians  and  boy  artificers,  full  normal  vision  is  required. 

For  candidates  for  other  artisan  ratings  and  for  stokers,  the  vision 
must  be  6/8. 

For  all  other  ratings,  including  writers,  ship's  stewards'  assistants, 
ship's  cooks,  sick  berth  staff,  boy  writers,  ship's  stewards'  boys,  and 
officers'  stewards  and  cooks,  the  vision  must  not  be  less  than  6/12. 

For  all  ratings  except  writers,  ship's  cook  ratings,  and  officers'  servants, 
the  colour  sense  must  be  normal. 

Defects  of  vision  must  only  be  due  to  errors  of  refraction,  and  must 
be  capable  of  correction  to  6/6  Snellen  by  means  of  glasses,  and  the  candi- 
date must  be  able  to  read  D  =  0,  6  without  the  aid  of  glasses. 

Marine  bandsmen,  sick  berth  staff,  Avriters,  ship's  steward  ratings, 
ship's  cook  ratings,  and  officers'  servants  are  allowed  to  wear  glasses. 

Home  Civil  Service. — Any  serious  defect  of  vision  disquahfies.  A 
moderate  degree  of  ordinary  short  sight  corrected  by  glasses  would  not 
as  a  rule  be  regarded  as  a  disqualification  ;  but  candidates  for  the  Cus- 
toms Outdoor  Service  are  liable  to  disqualification  for  any  defect  of  vision. 
Candidates  for  some  other  appointments  of  a  special  character  would  be 
rejected  for  colour-blindness,  but  for  ordinary  home  appointments  it  is 
not  by  itself  a  disqualification. 

No  precise  standard  of  eyesight  is  at  present  laid  down  for  candidates 
for  appointment  as  assistants  of  Customs  and  Excise.  Under  the  existing 
rules,  it  is  probable  that  a  moderate  degree  of  short  sight,  properly 
corrected  by  glasses,  would  not  of  itself  be  held  to  disqualify,  but  axiy 


628  APPENDIX. 

serious  defect  of  vision  would  be  a  disqualification.  The  Regulations, 
however,  are  liable  to  alteration,  and  the  Civil  Service  Commissioners 
cannot  say  what  rule  in  regard  to  eyesight  may  be  in  force  for  subsequent 
competitions. 

The  Commissioners  cannot  undertake  to  give  prospective  decisions 
in  the  case  of  intending  candidates,  or  to  define  more  closely  the  requisite 
standard. 

For  the  situations  of  Customs  Preventive  Man  and  Parkkeeper  in  the 
Royal  Parks,  candidates  must  have  vision  acute  enough  to  perform  their 
duties  without  the  use  of  glasses  ;  a  practical  test  is  made,  if  necessary, 
by  officers  of  the  departments  concerned. 

The  Indian  Civil  Service. — 1.  A  candidate  may  be  admitted  into  the 
Civil  Services  of  the  Government  of  India  if  ametropic  in  one  or  both  eyes, 
provided  that,  with  correcting  lenses,  the  acuteness  of  vision  be  not  less 
than  6/9  in  one  eye  and  6/6  in  the  other  ;  there  being  no  morbid  changes 
in  the  fundus  of  either  eye. 

2.  Cases  of  myopia,  however,  with  a  posterior  staphyloma,  may  be 
admitted  into  the  service,  provided  the  ametropia  in  either  eye  does  not 
exceed  2*5  D,  and  no  active  morbid  changes  of  chorioid  or  retina  be  present. 

3.  A  candidate  who  has  a  defect  of  vision  arising  from  nebula  of  the 
cornea  is  disqualified  if  the  sight  of  either  eye  be  less  than  6/12  ;  and  in 
such  a  case  the  acuteness  of  vision  in  the  better  eye  must  equal  6/6,  with 
or  without  glasses. 

4.  Squint  or  any  morbid  condition,  subject  to  the  risk  of  aggravation 
or  recurrence,  in  either  eye,  may  cause  the  rejection  of  a  candidate. 
The  existence  of  imperfection  of  colour  sense  will  be  noted  on  the 
candidate's  papers. 

India.  The  Departments  of  Forest,  Survey,  Telegraph,  Factories, 
and  for  various  Artificers.^ — 1.  If  myopia  in  one  or  both  eyes  exists,  a 
candidate  may  be  passed,  provided  the  ametropia  does  not  exceed  2*5  D, 
and  if  with  correcting  glasses,  not  exceeding  2 "5  D,  the  acuteness  of  vision 
in  one  eye  equals  6/9  and  in  the  other  6/6,  there  being  normal  range  of 
accommodation  with  the  glasses. 

2.  Myopic  astigmatism  does  not  disqualify  a  candidate  for  service  ; 
provided  the  lens  or  the  combined  spherical  and  cylindrical  lenses  re- 
quired to  correct  the  error  of  refraction  do  not  exceed  2*5  D  ;  the  acute- 
ness of  vision  in  one  eye,  when  corrected,  being  equal  to  6/6,  and  in  the 
other  eye  6/9,  together  with  the  normal  range  of  accommodation  with 
the  correcting  glasses,  there  being  no  evidence  of  progressive  disease  in 
the  chorioid  or  retina. 

3.  A  candidate  having  total  hypermetropia  not  exceeding  4  D  is  not 

1  Artificers  engaged  in  map  and  plan  drawing  may  be  considered 
separately,  and  this  standard  relaxed  if  it  appears  to  be  desirable. 


-4  PPENDIX.  629 

disqiialilicd,  provided  the  siglit  in  one  eye  (when  under  the  inlluencc  of 
atropine)  equals  0/9,  and  in  the  other  eye  equals  6/6,  with  +  4  D  or  any 
lower  power. 

4.  Hypermetropic  astigmatism  does  not  disqualify  a  candidate  for 
the  service,  provided  the  lens  or  comlMued  lenses  re<iuircd  to  correct  the 
error  of  refraction  do  not  exceed  4  J),  and  that  the  sight  of  one  eye  equals 
6/9  and  of  the  other  6/6,  with  or  without  such  lens  or  lenses. 

5.  A  candidate  having  a  defect  of  vision  arising  from  nebula  of  the 
cornea  is  disqualified  if  the  sight  of  one  eye  be  less  than  6/12.  In  such  a 
case  the  better  eye  must  be  emmetropic.  Defects  of  vision  arising  from 
pathological  or  other  changes  in  the  deeper  structures  of  either  eye,  which 
are  not  referred  to  in  the  above  rules,  may  exclude  a  candidate  for  ad- 
mission into  the  service. 

6.  Squint  or  any  morbid  condition,  subject  to  the  risk  of  aggravation 
or  recurrence,  in  either  eye,  may  cause  the  rejection  of  a  candidate.  The 
existence  of  imperfection  of  colour  sense  will  be  noted  on  the  candidate's 
pa})ers. 

India.  Public  Works  Department  and  Superior  Establishments, 
Railway  Department. — 1.  If  myopia  in  one  or  both  eyes  exists,  a  candi- 
date may  be  passed,  provided  the  ametropia  does  not  exceed  3*5  D,  and 
if,  with  correcting  glasses  not  exceeding  3'5  D,  the  acuteness  of  vision  in 
one  eye  equals  6/9  and  in  the  other  0/6,  there  being  normal  range  of 
accommodation  with  the  glasses. 

2.  Myopic  astigmatism  does  not  disqualify  a  candidate,  provided  the 
lens  or  the  combined  spherical  and  cylindrical  lenses  required  to  correct 
the  error  of  refraction  do  not  exceed  3"o  D  ;  the  acuteness  of  vision  in 
one  eye,  when  corrected,  being  equal  to  6/9,  and  in  the  other  6/6, 
together  with  normal  range  of  accommodation  with  the  correcting  glasses, 
there  being  no  evidence  of  progressive  disease  in  the  chorioid  or  retina. 

3.  A  candidate  having  total  liypermetropia  not  exceeding  4  D  is  not 
disqualified,  provided  the  sight  in  one  eye  (when  under  the  influence  of 
atropine)  equals  6/9,  and  in  the  other  eye  equals  6/6,  with  +  4  D  glasses, 
or  any  lower  power. 

4.  Hypermetropic  astigmatism  does  not  disqualify,  provided  the  lens 
or  combined  lenses  required  to  cover  the  error  of  refraction  do  ncjt  exceed 
4  D,  and  that  the  sight  of  one  eve  equals  6/9,  and  the  other  6/(>,  \\ith  or 
without  such  lens  or  lenses. 

5.  A  candidate  having  a  defect  of  vision  arising  from  nebula  of  the 
cornea  is  disqualified  if  the  sight  of  that  eje  be  less  than  6/12.  In  such  a 
case  the  better  eye  must  be  emmetropic.  Defects  of  vision  arising  from 
pathological  or  other  changes  in  the  deeper  structure  of  either  eye,  which 
are  not  referred  to  in  these  rules,  may  exclude  a  candidate. 

0.  Squint  or  any  morbid  condition,  subject  to  the  risk  of  aggravation 
o«-  recurrence,  in  either  eye,  may  cause  the  rejection  of  a  candidate.     Any 


C30  APPENDIX. 


imperfection  of  the  colour  sense  is  a  disqualification  for  appointment  to 
the  Engineering  Branch  of  the  Railway  Department,  or  as  Assistant 
Superintendent  in  the  Traffic  Department.  In  all  other  cases  a  note  as 
to  any  imperfection  of  colour  sense  will  be  made  on  the  candidate's  papers. 
The  Indian  Medical  Service,  and  the  Indian  Police  Department. — 

1.  Squint  or  any  morbid  condition  of  the  eyes  or  (i  the  lids  of  either  eye, 
liable  to  the  risk  of  aggravation  or  recurrence,  will  cause  the  rejection  of 
the  candidate. 

2.  The  examination  for  determining  the  acuteness  of  vision  includes 
two  tests  :  one  for  distant,  the  other  for  near  vision.  The  Army  test  types 
will  be  used  for  the  test  for  distant  vision,  without  glasses,  except  where 
otherwise  stated  below,  at  a  distance  of  20  feet ;  and  Snellen's  Optotypi 
for  the  test  for  near  vision,  without  glasses,  at  any  distance  selected  by 
the  candidate.  Each  eye  will  be  examined  separately  and  the  lids  must 
be  kept  wide  open  during  the  test.  The  candidate  must  be  able  to  read 
the  tests  without  hesitation  in  ordinary  daylight. 

3.  A  candidate  possessing  acuteness  of  vision,  according  to  one  of  the 
standards  herein  laid  down,  will  not  be  rejected  on  account  of  an  error  of 
refraction,  provided  that  the  error  of  refraction,  in  the  following  cases, 
does  not  exceed  the  limits  mentioned,  viz.  : — {a)  in  the  case  of  myopia,  that 
the  error  of  refraction  does  not  exceed  2*5  D  ;  (6)  that  any  correction  for 
astigmatism  does  not  exceed  2*5  D  ;  and,  in  the  case  of  myopic  astigma- 
tism, that  the  total  error  of  refraction  does  not  exceed  2*5  D. 

4.  Subject  to  the  foregoing  conditions,  the  standards  of  the  minimum 
acuteness  of  vision  with  which  a  candidate  will  be  accepted  are  as  follows  : — 

Standard  I. 

Bight  eye.  Left  eye. 

Distant  vision.— V  -  6/6.  V  =  6/6. 

Near  vision. — Reads  0,  6.  Reads  0,  6. 

Standard  II. 
Better  eye.  Worse  eye. 

Distant  vision. — V  =  6/6.  V,    without    glasses,   =  not    below 

6/60  ;  and  after  correction  with 
glasses,  =  not  below  6/24. 

Near  vision. — Reads  0,  6.  Reads  1. 

Standard  III. 
Better  eye.  Worse  eye. 

Distant  vision. — V,  without  glasses  V,    without    glasses,   =  not    below 
=  not    below    6/24  ;     and    after  6/24  ;    and,  after  correction  with 

correction  with  glasses,  =  not  be-  glasses,   =  not  below  6/12. 

low  6/6. 

]S^ear  vision. — Reads  0,  8.  Reads  1. 


APPENDIX.  631 

The  Indian  Pilot  Service,  and  Candidates  for  Appointments  as 
Guards,  Engine-drivers,  Signalmen  and  Pointsmen  on  Indian  Rail- 
ways.—  1.  A  candidate  is  disqualiiied  unless  both  eyes  are  emmetropic,  his 
acuteness  of  vision  and  range  of  accommodation  being  perfect. 

2.  A  candidate  is  disqiialihed  by  any  imjierfection  of  his  colour  sense. 

3.  Strabismus,  or  any  defective  action  of  the  exterior  muscles  of  the 
eyeball,  disqualifies  a  candidate  for  these  branches  of  service. 

The  Indian  Marine  Service,  including  Engineers  and  Firemen.—] . 
A  candidate  is  disqualified  if  he  have  an  error  of  refraction  in  one  or  both 
eyes  which  is  not  neutralised  by  a  concave  or  by  a  convex  1  D  lens,  or  some 
lower  power. 

2.  A  candidate  is  disqualified  by  any  imperfection  of  his  colour 
sense. 

3.  Strabismus,  or  any  defective  action  of  the  exterior  muscles  of  the 
eyeball,  disqualifies  a  candidate  for  this  branch  of  service. 

Royal  Irish  Constabulary. — A  candidate  for  Cadetship  in  the  Royal 
Irish  Constabulary  must  be  able  to  read  with  each  eye  separately,  and 
without  glasses,  Snellen's  Metrical  Test  Types  (Edition  1898)  numbered 
D  =  10,  at  20  English  feet,  and  those  numbered  D  =  0,  8  at  any  distance 
selected  by  the  candidate  himself.  Squint,  inability  to  distinguish  the 
principal  colours,  or  any  morbid  condition  liable  to  the  risk  of  aggravation 
or  recurrence  in  either  eye,  will  involve  the  rejection  of  the  candidate. 

The  British  Mercantile  Marine.  Form  Vision  Test. — The  test  is  the 
letter  test  on  Snellen's  principle,  for  all  candidates,  and  they  are  not 
allowed  to  wear  spectacles  or  glasses  of  any  kind. 

On  and  after  January  1,  1914,  a  higher  standard  of  Form  Vision  will 
be  required  of  candidates,  but  the  colour  vision  and  colour  ignorance 
tests  will  be  unaltered.     The  new  Form  Vision  Test  will  be  as  follows  : — 

If  a  candidate  can  read  correctly  at  a  distance  of  16  feet  nine  of 
the  twelve  letters  in  the  sixth  line  from  the  top  and  eight  of  the  fifteen 
letters  in  the  seventh  line  with  one  eye,  and  the  whole  of  the  eight  letters 
in  the  fifth  line  with  the  other  eye,  he  may  be  considered  to  have  passed 
the  test.  If  he  cannot  do  so,  his  case  is  submitted  to  the  Principal 
Examiner  of  Masters  and  Mates. 

Candidates  may  use  both  eyes  or  either  eye  when  being  tested  for  this 
standard. 

Candidates  who  before  January  1,  1914,  shall  have  obtained  any 
certificate  of  competency  as  Master  or  Mate  (foreign-going  or  home 
trade),  shall  have  the  option  of  undergoing  the  present  tests,  and  shall 
not,  in  order  to  obtain  certificates  of  higher  grades,  be  required  to  pass 
the  more  severe  test. 

Colour  Vision  Test. — The  colour  vision  of  candidates  is  tested  by 
Holmgren's  Method. 

Colour  Ignorance  Test. — The  object  of  this  test  is  to  ascertain  whether 


632  APPENDIX. 


the  candidate  knows  the  names  of    the  three  colours — red,  green,  and 
white — and  the  test  is  confined  to  naming  those  colours. 

The  Board  of  Trade  examinations  for  Form  Vision,  Colour  Vision, 
and  Colour  Ignorance  are  open  to  all  jDersons  intending  to  serve  in  the 
Mercantile  Marine,  and  all  such  persons  are  recommended  to  ascertain, 
by  means  of  these  examinations,  whether  their  vision  is  such  as  to  qualify 
them  for  service  in  that  profession  before  entering  upon  it. 


^scy 


+  5vi» 


^-o 


o06" 


INDEX. 


Aberration,  chromatic,  407  ; 
spherical,  407. 

Absolute  alcohol,  treatment  for 
ulcers,  134. 

Absorption  ulcer,  106. 

Accommodation,  5  ;  mechanism  of, 
5  ;  range  of,  6,  8  ;  and  abnormal 
refraction,  414  ;  anomalies  of, 
460  ;  amplitude  of,  6  ;  paralysis, 
of,  463  ;  spasm  of,  465  ;  syn- 
kinesis, 230. 

Acromegaly,  365. 

Acute  ascending  paralysis,  382. 

Acuteness  of  vision,  14. 

Advancement  operation  in  strabis- 
mus, 523. 

Albinismus,   224. 

Alexia,  cortical,  370. 

Amaurosis,  temporary,  104  ;  fugax, 
327  ;  quinine,  330  ;  from  filix 
mas,  331  ;  spinal,  354 ;  pre- 
tended, 393  ;  Grsefe's  test  in, 
393  ;  Harlan's  test  in,  394 ; 
crossed  diplopia  test  in,  393  ; 
Snellin's  coloured  types,  394. 

Amaurotic  family  idiocy,  375. 

Amblyopia,  glycosuric,  358  ;  cen- 
tral toxic,  358  ;  congenital,  391  ; 
ex  anopsia,  512  ;  during  preg- 
nancy, 391  ;  reflex,  391  ;  urae- 
mic,  392  ;  toxic,  349,353  ;  nervous, 
383  ;  nervous  in  neurasthenia, 
386  ;  nervous  in  hysteria,  388  ; 
nervous  in  traiunatic  neurosis, 
389. 

Ametropia,  414  ;  quantitative  de- 
termination of,  449. 

Amnesic  colour-blindness,  371. 

Anaphoria,  527. 

Anel's  syringe,  587. 

Angiomata,  007. 

Aniridia,  223  ;    traumatic.  213. 

Anisocoria,  374. 

Anisometropia,  447. 

Ankyloblepharon,  577. 

Anophthalmos,  cysts  with.  000. 

03: 


Anterior  chamber,  cysts  of,  21 G  ; 
haemorrhage  into,  284;  late  ap- 
pearance of,  in  cat.  operation.  280. 

Anterior  synechia,  04. 

Aphakia,  295. 

Aphasia,  307  ;   visual,  370. 

Arcus  ssnilus,  162. 

Argyll  Robertson  pupil.  381. 

Argyrol,  54. 

Argyrosis,  54. 

Arsenic,  poisoning  with,  350. 

Artificial  eyes,  200. 

Artificial  leech,  489. 

Aspherical  lenses,  297. 

Asthenopia,  accommodative,  434  ; 
muscular,  473,  527  ;  nervous,  383 

Astigmatism,  430  ;  regular,  430  ; 
hypermetropic,  437  ;  mixed,  437; 
myopic,  437  ;  estimation  of  the 
degree  of,  441;  lental,  445; 
irregular.  440. 

Astigmometer,  443. 

Ataxy,  hereditary,  382. 

Atrophy  of  optic  nerve,  simple, 
353  ;  consecutive.  353  ;  primary 
of,  354  ;    general  chorioidal,  424]^ 

Atropine,  action  of  on  pupil,  233  ; 
poisoning,  181  ;  eczema.  181  ; 
dangers  of,  182. 

Axial  neuritis,  349. 

Axis-finder  (Maddox's),  411. 

Bacteriology  of  conjunctivitis,  48. 

Basedow's  disease,  020. 

Bergeon's  treatment  for  rodent 
ulcer,  552. 

Binocular  vision,  473. 

Bitot's  spots,  97. 

Bjerrum's  test  for  central  scotoma. 
20. 

Blennorrhoea  neonatorum,  58. 

Blennorrhoea  of  the  lacrimal  sac, 
586. 

Blepharitis,  marginal,  543  ;  ul- 
cerosa, 543  ;  squamosa,  543  ; 
ectropion,  574. 


633 


INDEX. 


Blepharophimosis,    564  ;     (Cantho- 

plastic  operation),  564. 
Blepharoptosis,  554. 
Blepharospasm,    103,   554. 
Blind  spot  of  Marriotte,  19. 
Blue  blindness,  337. 
Bowels,  haemorrhages  from,  c57. 
British  mercantile  marine,  631. 
Buphthalmos,  260. 

Canaliculus,  obstrviction  of,  582 ; 
streptothrix  in,  582. 

Canthoplastic  operation,  566. 

Capsule  of  Tenon,  inflammation  of 
the,  598. 

Capsulotomy,  291. 

Carbolic  acid  for  corneal  ulcers,  134 

Carbon  dioxide  snow,  81,  547. 

Carcinoma  of  chorioid,  220;  of 
ciliary  body  and  iris,   217. 

Caruncle  lacrimale,  42  ;  tumours  of, 
101. 

Cataract,  anterior  polar  or  pyra- 
midal, 271  ;  black,  269 ;  cap- 
sular, 273  ;  central  capsular,  or 
pyramidal,  65  ;  central,  269  ;  com- 
plete, 261 ;  complete  congenital, 
268  ;  complete  of  young  people, 

268  ;  diabetic,  268  ;  fusiform  or 
spindle  shaped,  271;  glass-blower's, 

269  ;  Morgagnian,  262  ;  partial, 
269  ;  posterior  polar,  271.  272  ; 
punctate,  271 ;  secondary,  or  com- 
plicated, 272,  291  ;  senile,  261  ; 
total  secondary,  272  ;  trau- 
matic, 273  ;  zonular  or  lamellar, 
269. 

Cataract,  artificial  ripening  of, 
268 ;  combined  operation  for, 
278  ;  extraction  of  capsule  (in 
cat.  operation),  290  ;  extraction 
without  iridectomy,  288  ;  linear 
extraction  of,  277  ;  operations 
for,  275 ;  simple  operation  for, 
288  ;  spontaneous  cure  of,  264  ; 
pathogenesis  of  senile,  265. 

Cataract  extraction,  accidents  during 
operation.  284  ;  irregularities  in 
healing  after,  285. 

Cataracta  accreta,  272  ;  mem- 
branacea,  264  ;    nigra,  264. 

Cautery,  actual,  117. 

Cavernous  sinus,  thrombosis  of  the, 
502,  598. 

Cellulitis  of  orbit,  597. 

Central  chorioiditis,  191  ;  senile, 
guttate  chorioiditis,  191  ;  toxic 
amblyopia,  358.  ^^-      ._  _ 


Cerebral  synkinesis,  231. 

Cerebro-spinal  meningitis,  344. 

Chalazion,  546. 

Chemosis,  45,  91. 

Cherry-red  spot  in  obstruction  of 
retinal  vessels,  325. 

Chlorosis,   345. 

Choked  disc,  342. 

Chorea,  378. 

Chorio -retinitis,  314. 

Chorioid,  central  senile  areolar 
atrophy  of,  222  ;  coloboma  of, 
224;  detachment  of,  221,  288; 
extravasation  of  blood  in  the, 
215  ;  gyrate  atrophy  of  the 
retina     and,     330  ;      injuries     of, 

214  ;  malformations  of,  224  ; 
new  growths  of,  217  ;  posterior 
staphyloma  of,  221  ;    rupture  of, 

215  ;    sarcoma  of,  220. 
Chorioidal   exudation   near   macula 

lutea,  423  ;  degeneration  near 
macula  lutea,  423. 

Chorioiditis,  central,  191  ;  central 
senile  guttate,  191  ;  disseminated, 
189  ;  purulent,  192. 

Chromidrosis,  palpebral,   548. 

Chronic  nuclear  paralysis,  494. 

Chronic  polio-encephalitis  of  Wer- 
nicke, 494. 

Cilia,  excision  of,  566. 

Ciliary  body,  injuries  of,  214  ;  new 
growths  of,  217;    congestion,  45. 

Civil  service,  vision  required  for  the. 
627  ;    Indian,  628. 

Coloboma  of  chorioid,  224 ;  con- 
genital, of  up.  lid,  579  ;  of  iris, 
223  ;  of  lens,  225  ;  of  sclerotic, 
172. 

Colour  -  blindness,  358  ;  amnesic, 
371. 

Colour  fields,  inversion  of  the,  585  ; 
sense,  the,  10,  11  ;   tests,  13. 

Columbia  spirit  or  wood  alcohol, 
352. 

Commotio  retinae,  340. 

Congestion,  ciliary,  45  ;  conjunc- 
tival, 45  ;    papilla,  342. 

Conjunctiva,  diseases  of,  42  ;  ex- 
amination of,  42  ;  chemosis  of, 
91  ;  and  cornea,  examination  of 
in  infants  and  children,  44  ;  hy- 
peraemia  of,  45  ;  acute  blen- 
norrhof a  of,  or  purulent  ophthal- 
mia, 58  ;  tubercular  disease  of 
the,  84 ;  lupus  of  the,  86  ; 
syphilitic  disease  of  the,  87  ;  lim- 
bus   of    the,    42  ;     ulcers    of,    87  ; 


INDEX. 


637 


pempliigus  of  the.  89  ;  emphy- 
sema of  the.  91  ;  injuries  of  the, 
91  ;  degenerative  diseases  of,  93  ; 
hyahne.  colloid,  and  amyloid 
degeneration  of,  97  ;  cysts  of, 
98  ;  tumours  of,  99  ;  xerosis  of 
the,  130  ;  shrinking  of  the,  615  ; 
Weeks'  operation  for  shrinking 
of  the.  617;  epithelioma  and 
sarcoma  of,  100. 
Conjunctival  flap  (Kuhnt's),  121. 
Conjunctivitis,  4()  ;  varieties  of,  47  ; 
bacteriology  of ,  48  ;  catarrhal,  49  ; 
simple  acute.  49  ;  muco-puru- 
lent,  49  ;  diplobacillary,  or  an- 
gular, 55  ;  chronic  simple,  or 
chronic  catarrhal.  56  ;  mem- 
branous, 66  ;  croupous,  66,  67  ; 
diphtheric.  68  ;  granular,  70  ; 
tollicular.  82  ;  Farinaud's,  85  ; 
vernal,  87  ;  petrificans,  90  ;  phlyc- 
tenular, 102 ;  post  operative, 
286  ;  nitrate  of  silver  in,  54  ;  an- 
gular, 55. 
Convergence,  9  ;  range  and  ampli- 
tude of,  9  ;  insufficiency  of,  425, 
534. 
Corectopia,  223. 

Cornea,  diseases  of,  110  ;  clinical 
methods  of  examining,  110  ;  in- 
flammations of,  112  {sp,e  Keratitis); 
ulcerative  inflammations  of,  112 
{see  also  Ulcers) ;  deep  ulcer  of 
the,  123  ;  fistula  of  the,  123  ; 
infantile  ulceration  of  the,  130  ; 
non-ulcerative  inflammation  of 
the,  136 ;  abscess  of  the,  136  ; 
ring  abscess  of  the,  137  ;  syphi- 
litic diseases  of  the,  137  ;  gumma 
of  the,  141  ;  sclerotising  opacity 
of  the,  144 ;  transverse  calcare- 
ous films  of  the,  145  ;  cal- 
careous film  of  the,  145  ;  super- 
ficial epithelial  dystrophy  of,  146  ; 
ectasies  of  the,  146  ;  staphyloma 
of  the,  146  ;  abscission  of,  147  ; 
conical,  150  ;  atrophic  degenera- 
tion of  the  margin  of  the,  152  ; 
tumours  of  the,  153  ;  injuries  of 
the,  153  ;  foreign  bodies  in  the, 
153  ;  simple  traumatic  losses  of 
substance,  or  abrasions,  155  ; 
recurrent  abrasion,  156 ;  dis- 
junction of  the,  156  ;  recurrent 
traumatic  keratalgia,  156;h8Dmor- 
rhagic  discoloration  of  the,  157  ; 
injuries  with  caustic  substances 
of  the,   157  ;  perforating  injuries 


of  the,  158  ;  opacities  of  the,  160  ; 
globosa,  260  ;    limbus  of  the,  42. 

Corneal  microscope,   112. 

Corpuscle,  or  trachoma  cells,  71. 

Credo's  method  of  prophylaxis  in 
ophthalmic  neonatorum,  60. 

Crossed  diplopia  test,  393. 

Crossed  hemiplegia,  501. 

Crystalline  lens,  diseases  of.  261  ; 
dislocation  of,  259,  294  ;  absence 
of  (aphakia),  295  ;  congenital 
defects  of,  295  ;  coloboma  of, 
295;  opacities  of  [see  Cataract). 

Cyclitis,  187  ;  acute,  187  ;  tuber- 
cular, 189;    treatment  of,  189. 

Cyclodialysis  for  glaucoma  (Heine's 
operation),  256. 

Cyclophoria,  533. 

Cycloplegia,  463. 

Cysticercus,  subretinal,  335  ;  sub- 
conjunctival, 98  ;  in  vitreous 
humour,   311. 

Cystoid  cicatrix,  288. 

Cysts,  of  the  conjunctiva,  simple,  98; 
retention,  98  ;  implantation,  98  ; 
congenital,  98  ;  of  the  iris,  216  ; 
of  the  anterior  chamber,  216  ; 
Meibomian,  547  ;  tarsal,  547  ; 
of  the  lacrimal  gland,  594  ;  or- 
bital, 605  ;  dermoid,  605  ;  with 
anophthalmos,  606  ;  parasitic, 
606. 

Dacryoadenitis,  592. 
Dacryocystitis,  chronic,  586  ;  acute, 

591. 
Dacryocystorhinostomy,  591. 
Dacryolith,  582. 
Dacryops,  594. 
Dalrymple's  sign,  621. 
Dermo-lipoma  of  conjunctiv^a,  99. 
Descemet's  membrane,  110. 
Deviometer  (Worth's),  515. 
Diabetes,  retinal  affections  in,  318. 
Diaphanoscopy,  219. 
Diaphragm  test  (Harman's),  535, 
Diffuse  sclerosis  of  brain,  374. 
Dioptric  system,  3. 
Dioptric  unit,  409. 
Diplopia,  474  ;   false  image  in,  474  ; 

homonymous,  474  ;   crossed,  475  ; 

monocular,  474. 
Diploscope,  of  Remy,  535. 
Disc,  choked,  342  ;    waxy,  354. 
Discission,  293. 

Disseminated  sclerosis,  346,  372. 
Distichiasis,  74,  565. 
Donders'  diagram,  460. 


638 


INDEX. 


Dor's    treatment    for    detached    re- 
tina, 339. 
Dunbar's  hay  fever  serum,  70. 
Dyslexia,  370. 

Ectopia  of  lens,  295. 

Ectropion,  572  ;  of  lower  lid,  57  ; 
blepharitis,  574  ;  cicatricial,  574  ; 
muscular,  572  ;  paralytic,  577  ; 
senile,  572  ;  of  uveal  pigment, 
224  ;   Wolfe's  operation  for,  576. 

Eczema  after  use  of  atropine,  181  ; 
of  eyelids,  541  ;  sc[uamosa,  543  ; 
pustulosa,  543. 

Edridge-Green's  theory  of  colour 
sense,  11. 

Electric  light,  blinding  of  retina  by, 
333. 

Electro-magnets  (Snell's),  308  ; 
Haab's  Giant,  309. 

Electrolysis,  547,  566. 

Elementary  optics,  396. 

Elephantiasis  lymphangioides,  542 ; 
nostras,  542. 

Elliot's  operation  for  glaucoma, 
254  ;    trephine,  254. 

Embolism  and  thrombosis  of  cen- 
tral artery  of  retina,  325. 

Emmetropia,  4. 

Emphysema  of  eyelids,  578. 

Endarteritis  of  retinal  vessels,  323. 

Endophthalmitis,  210. 

Enophthalmos.  602. 

Entropion,  568  ;  spastic,  568  ;  se- 
nile, 568  ;  Snellen's  operation 
for,  569  ;  Berlin's  operation  for, 
570  ;  Hotz's  operation  for,  570  ; 
operation  by  excision  of  skin,  570. 

Ermcleation  or  excision  of  eyeball, 
206. 

Epicanthus,  505,  555,  578. 

Epilation,  566. 

Epilepsy,  378. 

Epiphora,  580. 

Episcleritis,  164  ;  hot  eye  (Hutchin- 
son), 164  ;  periodic  transient 
(Fuchs),    164. 

Epithelial  plaques,   93  ;   xerosis,  97. 

Epithelioma  of  conjunctiva,  100  ; 
of  eyelids,  553. 

Erythropsia,  394. 

Esophoria,  527. 

Ethmoid  cells,  disease  of,  618. 

Euphos  glass,  334,  413. 

Everbusch's  operation  for  ptosis, 
555,  557. 

Evisceration,  147,  207. 

Exophoria,   527. 


Exophthalmic  goitre,  620. 

Exophthalmometers,  596. 

Exophthalmos,  343,  596  ;  pulsating^ 
609  ;    intermittent,  609. 

Exostoses  of  orbit,  607. 

Expulsive  haemorrhage  in  cataract 
extraction,  286. 

External  rectus,  paralysis  of,  478. 

Extorsion  (wheel  motion),  467. 

Eyeball,  rupture  of,  169. 

Eyelids,  eczema  of,  541  ;  oedema 
of,  541  ;  angio-neurotic  oedema 
of,  542;  solid  oedema  of,  5; 2; 
elephantiasis  lymphangioides  of, 
542  ;  elephantiasis  nostras,  542  ; 
marginal  blepharitis  of,  543 ; 
hordeolum  of,  545  ;  chalazion, 
546 ;  milium,  547  ;  molluscum 
contagiosum,  547  ;  telangiectic 
tumours  or  naevi  of,  547  ;  xan- 
thelasma of,  547  ;  syphilitic 
affections  of,  550  ;  vaccine  vesi- 
cles on,  551  ;  neuro-fibroma  of,. 
553  ;  lymphoma  of,  553  ;  epi- 
thelioma, sarcoma  and  lupus  of, 
553  ;  gangrene  of,  553  ;  ptosis, 
554 ;  symblepharon,  562  ;  ble- 
pharophimosis,  564 ;  entropion 
of,  568  ;  ectropion  of,  574  ;  anky- 
loblepharon, 577  ;  injuries  of, 
677  ;  emphysema  of,  578  ;  colo- 
boma  of,  579. 

False  image  in  diplopia,  474. 

Far    point,    4,    6,    415  ;     in    hyper- 

metropia,  429  ;    in  myopia,  415. 
Fatigue  field,  385. 
Fergus's  operation  for  ptosis,   555, 

559  ;    for  ectropion,  573. 
Fibrolysin,  302. 
Fibroma  of  sclerotic,  168. 
Field    of     vision,     17  ;      concentric 

contraction  of,  389. 
Fifth  nerve,  paralysis  of,  505. 
Fixation,  line  of,  ^3  ;    field  of,  471  ; 

binocular,  473. 
Fluorescine,  111. 

Focal  or  oblique  illumination,  110. 
Follicular  conjunctivitis,  82. 
Folliculosis,  82. 
Foreign  body  in  eye,  303  ;   detection 

of,  304. 
Form  sense,  14. 
Fornix,  excision  of,  79. 
Fourth  nerve,  paralysis  of,  503. 
Fovea  centralis,  40. 
Friedrich's  disease,  382. 
Frohlich's  syndrome,  365. 


INDEX. 


(130 


Frontal  sinus,  the,  612. 
Fusion,  sense  of.  473.  510. 

Galvanism  in  paralyses,  490. 

Ganglia,  primary  ojitic.  'MVl. 

General  paralysis  of  the  insane.  .374 

Gerlier's  disease,  494. 

Gerontoxon.   102. 

Gigantism,  305. 

Glaucoma,   primary,    235  ;     ehronic 
simple,     235,     238  ;      congestive 
235  ;       chronic      non-congestive 
238  ;  acute,  243  ;  acute  congestive 
243  ;      fulminans,      245  ;       suba 
cute,     246  ;      etiology     of.     246 
pathology    of.    246  ;     malignant 
250  ;      non-operative     treatment 
of,  257  ;  secondary,  258,  291,  328 
haemorrhagic.  259  ;  ElHot's  opera- 
tion for,    253  ;     tension   in,    230 
operations  for,  250. 

Glaucomatous,  ring,  240  ;  eyes, 
treatment  of  painful  blind,  258. 

Globe,  evisceration  of,   147. 

Glycosuric  amblyopia,  358. 

Goggles,  airtight,  89. 

Goitre,  exophthalmic,  620. 

Gonorrhoeal  iritis,  keratitis  and 
scleritis,  05  ;  ophthalmia,  58  ; 
ophthalmia,   metastatic,  65. 

Grady's  forceps,  78. 

Graefe's,  Alfred,  test  for  pretended 
amaurosis,  393. 

Grafting,  Wolfe  and  Lefort's  method 
of,  577. 

Gram's  method  of  staining,  49. 

Granular  conjunctivitis,   70. 

Graves'  disease,  620. 

Gumma  of  cornea,  141  ;  sclerotic, 
167. 

Haab's  magnet,  309. 

Haemophthalmos,   170. 

Haemorrhage  into  anterior  chamber, 
in  cat.  operation,  284  ;  in  eye- 
lids, 601  ;  from  stomach,  bowels 
or  uterus,  357  ;  in  retina  at 
yellow  spot,  424. 

Haemosiderin,   150. 

Hallucinations,  visual,  371. 

Harlan's  operation  for  symble- 
pharon,  564  ;  test  for  pretended 
amaurosis,  394. 

Harman's  diaphragm  test,  535. 

Haselberg's  test  types,  394. 

Hay  fever,  70. 

Heine's  operation  for  glaucoma, 
256. 


Helmholtz's  ophthalmoscope,  29. 

Hemiachromatopsia,  3()9. 

Hemianopic  pupil,  3()9. 

Hemianopsia,  343,  360  ;  relative. 
301  ;  homonymous,  301  ;  bi- 
temporal. 301,  305;  superior  or 
inferior,  301  ;  altitudinal,  361  ; 
nasal,  301,  3«)5  ;  double,  361; 
localisation  of  lesion  in  ca,ses  of, 
304  ;  heteronymous,  305  ;  transi- 
tory, 390. 

Hemiplegia,  crossed,  501. 

Hereditary  ataxy  (Friedrich's 
disease),  382. 

Hering's  drop  experiment,  473; 
theory  of  colour  sense,  11. 

Hernia  cerebri,   000. 

Herpes  cornea?  febrilis,  131  ;  herpes 
zoster  ophthalmicus,  548. 

Hertel's  exophthalmometer,  590. 

Hess's  operation  for  ptosis,  555,  558. 

Heterochromia,   224. 

Heterophoria,  391,  526  ;  svmptoms 
of,  532. 

Heurteloup's  artificial  leech,  300, 322. 

Hirschberg's  operation  for  total 
post-synechia,  209  ;  method  of 
measuring  strabismus,  513. 

Hippus,  232. 

Holmgren's  colour  test,   13. 

Holth's  operation  for  glaucoma,  250. 

Home  civil  service,  027. 
i    Hordeolum,   545. 

Hot  eye,  104. 

Hotz's  operation  for  senile  entro- 
pion, 570. 

Hyaline  outgro\^ths  for  optic  disc. 
357. 

Hyaloid  artery,  persistent,  312. 

Hydrocephalus,  344,  377. 

Hydrophthalmos,  congenital,  260. 

Hypermetropia,  428  ;  definition  and 
optical  causes,  428  ;  senile,  429  ; 
optical  correction  of,  430  ;  de- 
termination of  degi-ee  of,  431  ; 
amplitude  of  accommodation  in, 
432  ;  angle  7  in,  432  ;  varieties 
of,  432  ;  prescribing  glasses  in, 
435  ;  far  point  in.  429. 

Hyperphoria,   527. 

Hypha^ma,   170,  211. 

Hypopyon,  114. 

Hysteria,  nervous  amblyopia  in^ 
383. 

Idiocy,  amaurotic  family,  375. 
Indian  civil  service,  etc.,  vision  re- 
quired for,  628. 


<)43 


INDEX. 


Infantile  paralysis,  378. 

Insufficiency,  muscular,  472. 

Intorsion  (wheel  movement),  467. 

Intra-muscular  injections  of  mer- 
cury, 183. 

Intra-ocular  tumours,  259. 

Iridectomy,  225. 

Iridencleisis  (Holth's  operation)  for 
glaucoma,  256. 

Irideremia,  223. 

Irido-cyclitis,  185. 

Iridodialysis,  212. 

Iridodonesis,  295. 

Iridotomy,  292. 

Iris,  inflammation  of,  173  ;  injuries 
of,  211  ;  bombe,  175  ;  abnor- 
malities in  colour  of,  224  ;  de- 
hiscence of,  213  ;  retroflexion  of, 
213  ;  new  growths  of,  216  ;  cysts 
of,  216 ;  solitary  tubercle  of, 
216;  sarcoma  of,  216;  malfor- 
mations of,  223  ;  coloboma  of, 
223  ;  operations  on,  225. 

Iritis,  173;  acute,  173;  acute  pri- 
mary, symptoms  of,  175  ;  acute 
primary,  etiology  of,  177;  acute 
primary,  treatment  of,  180  ;  syphi- 
litic, 177;  gonorrhceal,  177; 
tubercular,  178;  rheumatic,  180 ; 
chronic,  185;  serous  (or  cyclitis), 
259  ;    plastic,  287. 

Jacob's  ulcer,  551. 
Japanese  muff  warmers,  117. 
Jequiritol,  81. 
Jequirity,  79. 

Kenneth  Scott's  operation  for 
senile  entropion,  573. 

Keratalgia,  recurrent  traumatic, 
156. 

Keratitis,  102 ;  primary  phlycte- 
nular, 102  ;  neuro  -  paralytic, 
131  ;  dendriform,  133  ;  bullous, 
135;  fascicular,  103;  filamentary, 
135  ;  aspergillina,  135  ;  diffuse 
interstitial  or  parenchymatous, 
137,  143  ;  specific,  punctiform, 
interstitial,  141  ;  guttate  or 
nodular,  141  ;  grating-like  or 
reticular,  141 ;  discoid  or  annular, 
142  ;  disciform  of  Fuchs,  142  ; 
tubercular,  143  ;  punctate,  144  ; 
punctata  superficialis,  144  ;  ri- 
band-like, 145  ;    striped,  286. 

Keratoconus,    150. 

Keratomalacia,  130,   141. 

Keratoplasty,  161. 


Knapp's    operation   for    tumour    of 

optic  nerve,  611  ;    roller  forceps. 

78. 
Koch's  old  tuberculin,  180. 
Koch-Weekes  bacillus,  53. 
Komoto's  operation  for  staphyloma. 

149. 
Kronlein's  resection  of  orbit,  618. 
Kuhnt's     conjunctival     flap,     121  ; 

operation  for  senile  entropion,  573. 

Lacrimal  apparatus,  diseases  of 
the,  580. 

Lacrimal  gland,  inflammation  of 
the,  592  ;  tumours  of  the,  593  ; 
extirpation  of  the,  594  ;  tuber- 
cular tumour  of  the,  594  ;  cysts 
of  the,  594  ;  symmetrical  chronic 
swelling  of  salivarv  gland  and, 
594. 

Lacrimal  sac,  blenorrhoea  of,  586  ; 
extirpation  of,  588  ;  treatment 
with  protargol  and  peroxide  of 
hydrogen,   588. 

Lacrimation,  332. 

Lagophthalmos,  504. 

Lagrange's  operation  for  glau- 
coma, 252. 

Lambkin's  mercurial  treatment, 
183 

Landry's  disease,  383. 

Lead-poisoning,  346. 

Leber's  disease,  347. 

Leiter's  tubes,  61. 

Lens,  crystalline,  diseases  of,  261  ; 
dislocation  of,  258,  294  ;  opacity 
of  [see  Cataract). 

Lens  measurer,  411. 

Lenses,  401 ;  spherical,  401 ;  spheri- 
cal   images     formed     by,     405 ; 
meniscus,  402  ;    periscopic,    402  ; 
optical   defects  of,  407  ;  cylindri- 
cal, 407  ;   sphero-cylindrical   and 
toric,    408  ;    numbering  of,    409 
recognition     of    spherical,     410 
recognition    of    cylindrical,   410 
decentration  of,  412  ;  prescribing 
of  cylindrical,  446  ;  bifocal,  463. 

Lenticonus,  295. 

Leontiasis  ossium,  597. 

Leprosy,  179. 

Leucaemia,  179. 

Leucoma  of  cornea,  116,  160. 

Light-sense,  10  ;  Bjerrum's  test  for, 
10  ;   reflex,  229. 

Lithiasis  of  conjunctiva,  96. 

Lohlein's  operation  for  cronea 
transplantation,  162. 


INDEX. 


641 


Lupus,  of  conjunrtiva,  S('»  ;  of  ov<^- 

iids,  553. 
LynipluidcMioma  ot  eyelids,  553. 
Lymphoma    of    chorioid,    220  ;     of 

conjunctiva,  100;  of  eyelids,  553. 

-AI.u-Li.A  (conical),   IKi,  160. 

Macula  lutea,  34,  38,  340  ;  chorioi- 
dal  degeneration  near  the,  423  ; 
ehorioidal  exudation  near  the,  423. 

.Maculo-cerebral  degeneration,  376. 

.Maddox's  axis  finder,  411;  tangent 
scale,  515  ;  double  prism,  529  ; 
rod  test,  530  ;    wing  test,  53 1 . 

Magnet,  Haab's  Giant  electro-,  .309; 
Snell's,  308. 

Marginal  blepharitis.  543. 

Maxillary  antrum,  614. 

Measurement  of  convergent  stra- 
bismus, 513. 

Megalopsia,  190. 

Meibomian  glands,  45  ;    cysts,  546. 

Membranous  conjunctivitis,  6(). 

Meningitis,  376;  tubercular,  344; 
non-tubercular,  344  ;  cerebro- 
spinal, 344,  377  ;  acute  tubercular, 
377;  traumatic,  377. 

Menstruation,  suppression  of,  345. 

Metamorphopsia,  190,  315,  321. 

Metre  angle,  the,  9. 

Micropsia,  190,  464. 

Migraine,  3  9  J. 

^ligratory  ophthalmitis,  210. 

Mikulicz's  disease,  594. 

Miliary  tubercular  nodules,   144. 

Millium,  547. 

Mind  blindness,  371. 

Miosis,  214. 

Miotics,  234. 

Mirror,  concave,  452  ;  plane,  453. 

Moebius'  sign,  622. 

Mole,  or  nsevus,  99. 

Molluscum,  547. 

Molluscum  contagiosum,  547. 

Motais'  operation  for  ptosis,  555, 
556. 

Mouches  volantes,  302. 

Mucocele,  586. 

Mules'  operation,  148. 

Muscse  volitantes,  302. 

Myasthenia  gravis,  496. 

Mydriasis,  214. 

Mydriatics,  233. 

Myelitis,  347,  382. 

Myoclonic  nystagmus,   540. 

Myodesopsia,  302. 

Myopia,  or  short  sight,  414; 
optical  correction  of,  416  ;    diag- 

41 


nosis  and  determination  of  the 
degree  of,  417  ;  amplitude  of 
acconnnodation  in,  418;  range 
of  accommodation  in,  419;  the 
angle  7  in,  419  ;  etiology  of,  420; 
simi)l(>  or  non-progreysive,  421  ; 
spasmodic,  421  ;  symptoms  of, 
421  ;  pernicious,  422  ;  the  black 
spot  in,  425  ;  management  of,  425  ; 
l)rescribing  of  glassesj  in,  425  ; 
operative  cure  of,  425. 

Myopic  crescent,  422. 

Myopic  eye,  far  point  of  the,  415. 

Myosarcoma,   217. 

Myotonia  congenita,  382. 

N^vus  of  eyelids,  547  ;  of  conjunc- 
tiva, 99. 

Nasal  duct,  stricture  of,  583. 

Navy,  Royal,  vision  reqiiired  for, 
627. 

Near  point,  6. 

Nebula  of  cornea,  115,  160. 

Nervous  amblyopia,  383. 

Neuritis,  peripheral,  346 ;  here- 
ditary optic,  347  ;  retrobulbar, 
or  axial  optic,  347  ;  optic,  asso- 
ciated with  cerel^ro-spinal  rhinor- 
rhoea,  349  ;    axial,  349. 

Neurofibroma,  553  ;  neurofibroma- 
tosis, 260. 

Neuroma,  plexiform,  545. 

Neurosis,  traumatic,  nervous  am- 
blyopia in,  389. 

Night  blindness,  190,  392. 

Nitrate  of  silver  in  conjunctivitis, 
54. 

Nuclear  paralysis,  492. 

Nystagmus,  undulatory,  536 ;  rhyth- 
mic,   536 ;    amblyopic    or   ocular, 

'  537  ;  coal  miner's,  537  ;  vestibular, 
538  ;  spontaneous,  539 ;  in  dis- 
eases of  nervous  system,  539 ; 
voluntary,  540  ;"^ hereditary,  540  ; 
spasmus  nutans,  540  ;  myoclonic, 
540  ;  latent,  540. 

Oblique  illumination,  110. 

(Edema,  541  ;  angioneur  o  ic,  542  ; 
solid,  542  ;  elephantiasis  lym- 
phangioides,  542  ;  elephantiasis 
nostras,  542. 

Opacities  in  refractive  media,  35  ; 
of  the  cornea,  160. 

Opaque  nerve  fibres,  38. 

Ophthalmia,  46 ;  purulent,  58  ; 
purulent  prophylaxis,  Crede's 
method  of,  60,  61  ;  purulent,  Lei 


642 


INDEX. 


>er's  tubes  in,.  ()1  ;  metastatic, 
gonorrhoeal,  05 ;  granular,  70 ; 
Egyptian,  70  ;  military,  70  ;  acute 
granular,  73  ;  chronic  granular, 
73;  nodosa,  86,  179;  electric, 
333;  tarsi,  543  ;  neonatorum,  58  ; 
phlyctenular,  102. 
Ophthalmitis,  sympathetic,  193, 
195  prognosis  in,  202;  treatment 
of,  203  ;  prophylactic  operations 
for,  206  ;  therapeutic  operations 
for,  207  ;  optical  operations  for, 
208  :    pathology  of,  209 

Ophthalmoplegia  externa,  492  ;  in- 
terna, 492  ;    universa,  492. 

Ophthalmoplegic  migraine,  491. 

Ophthalmoscope,  the,  26 ;  Helm- 
holtz's,  29  ;  modern,  29  ;  methods 
of  ushig,  30  ;  direct  method,  30  ; 
indirect  method,  31  ;  Gullstrand's, 
33  ;  electric,  36 ;  estimation  of 
refrav-'tion  with,  447  ;  refraction, 
449. 

Optic  amnesia,  371. 

Optic  atrophy,  hereditary,  34  7  ; 
simple,  353;  consecutive,  35  3; 
chorioido-retinal,  354  ;  primary , 
354  ;  from  poisoning  with  organic 
preparations  of  arsenic,  356 ; 
treatment  of,  356, 

Optic  axis,  3  ;  disc,  or  papilla,  36  ; 
ganglia,  primary,  362. 

Optic  nerve,  atrophy  of,  353 ; 
chorioido-retinal  atrophy  of,  354  ; 
injuries  of,  357 ;  tumom-s  of, 
609 ;  examination  of,  34  ;  diseases 
of,  341. 

Optic  neuritis,  199,  341  ;  hereditary, 
347  ;  retrobulbar,  or  axial,  347  ; 
associated  with  cerebro-spinal 
rhinorrhoea,   349. 

Optical  defects  in  lenses,  406. 

Optics,  elementary,  396. 

Ora  serrata,  40. 

Orbicular  sign  in  hemiplegia,  505. 

Orbicularis  muscle,  clonic  cramp, 
of,  553  ;    tonic  cramp  of,  554. 

Orbit,  diseases  of  the,  596  ;  perios- 
titis of  the,  598  ;  caries  of  the, 
600 ;  injuries  of  the,  600  ;  em- 
physema of  the,  602  ;  tumours  of 
the,  602  ;  carcinoma  of  the,  608  ; 
cysts  of  the,  605,  606 ;  sym- 
metrical tumours  of  ^the,  608  ; 
angiomata  of  the,  607  ;  exos- 
toses of  the,  607  ;  temporary  re- 
section of  outer  wall  of  (Kron- 
lein's  op,),  618. 


Orbital  cellulitis,  597  ;    cysts,  605. 

Orbital  muscles  and  their  derange- 
ments, 466  ;  paralysis  of,  476  ; 
cerebral^paralysis  of,  ,497. 

Orientation,   471. 

Orthophoria,   526. 

Osteo-sarcoma  of  chorioid,  220. 

Oxycephaly^  597. 

Palpebral  cliromidrosis,  548. 

Pannus,  71,  75. 

Panophthalmitis,  192,  196.  y 

Papilla,  optic,  cupping^of ,  238  ;  con- 
gestion, 342  ;  and  intracranial 
tumours,  343. 

Papilhtis,  199. 

Papillcedema,  317,  342. 

Papilloma,  or  papillary  fibroma  of 
conjunctiva,    100. 

Paracentesis  of  anterior^chamber, 
118 ;  in  sympathetic  ophthal- 
mia, 208. 

Parallax,  37,  239. 

Paralysis  of  accommodation,  463  ; 
of  orbital  muscles,  476 ;  of  external 
rectus  of  left  eye,  478  ;  of  superior 
oblique  of  left  eye,  480  ;  of  third 
nerve,  481,  500  ;  measurement  of 
degree  of,  of  orbital  muscles,  488  ; 
of  orbital  muscles,  causes  of,  488  ; 
intermitting  of  third  nerve  of  one 
eye,  491  ;  of  third  nerve,  with 
cyclical  spasm,  492  ;  nuclear,  492 ; 
nuclear,  chronic,  494  ;  conjugate 
lateral,  495  ;  fascicular,  496  ; 
cerebral,  of  orbital  muscles,  497  ; 
of  fourth  nerve,  503  ;  of  sixth 
nerve,  503  ;  of  seventh  nerve, 
504  ;  of  fifth  nerve,  505  ;  rheu- 
matic, 488  ;  ^and  ataxy  of  orbital 
muscles,  380  ;    agitans,  378. 

Paralytic  strabismus,  472  ;  ectro- 
pion, 577. 

Parasitic  disease  of  retina,  335. 

Parinaud's  conjunctivitis,  85. 

Paster  lenses,  462. 

Pemphigus  of  conjunctiva,  89. 

Perimeter  method  of  measuring 
strabismus,  516. 

Perimetry,  17. 

PeripheralJ neuritis,    346. 

Peritomy,   81. 

Peroxide  of  hydrogen  for  lacrimal 
sac,  588. 

Persistent  hyaloid  artery,  312  ; 
pupillary  membrane,  223. 

Pfiiiger's"method  of  tarsoraphy,  562. 

Phlj^ctens,  niultiple,  or  miliary,  103. 


INDEX. 


fi43 


Phlyctenular  conjunctivitis  and 

keratitis.  102. 
Photometer,    10. 
Photophobia,   104,  3.32. 
Photopsifp,   387. 
Phthoiriasis  cilioruin,  545. 
Phthi.sis  bulbi,  170. 
Physioloofica]     excavation     of     tlio 

papilla,    37. 
Pigment  spots  in  sclerotic,  108. 
Pinguecula.    93. 
Placedo's  disc,  447. 
Plane  glass,  397. 

Pl(>xiform  neuroma  of  eyelids,  553. 
Plica  semilunaris,  42. 
Pneumococcus,  53. 
Polioencephalitis,  chronic,  superior, 

494. 
Pollentine,  70. 
Polycoria,  223. 
Polyopia,  265. 

Polypus    and    granuloma    of    con- 
junctiva,   100. 
Post-operative   conjunctivitis,    280. 
Posterior  staphj-^loma,  422. 
Pre-retinal  haemorrhages,  320. 
Presbyopia,  460. 

Priestley    Smith's   scotometer,    20  ; 
method  of  measuring  strabismus, 
514  ;     heteroscope,    518 ;     opera- 
tion for  tarsoraphy,  562. 
Prisms,    397  ;     numbering  of,   398  ; 
uses     of,     401  ;      prescribing    of, 
401  ;    tests  with,  528  ;'^^Maddox's 
double,  529. 
Projection  of  light,  24,  276. 
Proptosis,  596. 

Protargol,  54  ;  for  lacrimal  sac,  588. 
Protective  glas-ses,  413. 
Prothesis  oculi,  206.  i 
Pseudo-glioma,      298  ;      hypopyon, 

175. 
Pterygium,  93. 

Ptosis,  481,  554';  sympathetic, 
501  ;  paralytic,  554  ;  congenital, 
555,  56);  adiposa,  555,  560; 
operations  for,  555 ;  hysterical, 
560. 
Punctate  deposits  on  cornea,  144. 
Punctum  lacrimale,  malposition  of, 

580  ;    stenosis  of,  581. 
Punctum  proximum,  6. 
Punctum  remotum,  6  ;    in  H.,  429  ; 

in  M.,  415. 
Pupil,  229  ;   hemianopic,  369  ;    con- 
traction[of,  229;  dilatation  of,' 230 ; 
action    of    mydriatics    on,    233 ; 
action  of  niiotics  on,  234  :  Argyll 


Robertson,   381  ;  symptom,  Wer- 
nicke's, 369  ;  sensory  reflex,  231. 
Pyramidal  cataract,  65. 

QuiNiNR  amaurosis,  330. 

Radhtm.  81. 

Railway  spine,  383. 

Range  of  accommodation,  6. 

Real  inverted  imago  of  convex 
lens,  405. 

Red  vision,  394. 

Reflection,  laws  of,  26. 

Refraction,  4,  396 ;  normal,  4  ; 
index  of,  397  ;  abnormal  and  ac- 
commodation, 414 ;  estimation 
of,  447  ;  ophthalmoscope,  449. 

Remy's  diploscope,  535. 

Resorcin,  56. 

Retina,  diseases  of,  313  ;  inflam- 
mation of,  314  ;  capillary  angio- 
matosis of,  323  ;  obstruction  of 
central  artery  of,  325  ;  atropliies 
and  degenerations  of,  328  ;  gyrate 
atrophy  of,  330  ;  blinding  of  by 
directsunliglit,  331 ;  blinding  of  by 
electric  light,  333  ;  tumours  of  the, 
334  ;  glioma  of  the,  334  ;  tubercle 
of  the,  335  ;  cysticercus  under  the, 
335 ;  detachment  of  the,  336, 
424  ;  traumatic  affections  of  the, 
339  ;  traumatic  anaesthesia  of  the, 
339  ;  traumatic  oedema  of  the, 
340 ;  haemorrhage  in,  at  yellow 
spot,  424  ;  hyperaemiaof  th(\  313. 

Retinal  adaptation,  11  ;  vessels,  39  ; 
diseases  of,  323 ;  haemorrhages, 
320  ;    affections  in  diabetes,  318. 

Retinitis,  314;  albuminin-ica,  316; 
syphilitic,  314;  loucaemic,  319; 
metastatic,  319  ;  exudative,  322  ; 
haemorrhagica  externa  (Coats), 
322  ;  circinata,  322  ;  proliferans, 
301,  322;  hfeniorrhagic,  327  j 
piy:mentosa.  328,  392  ;  punctata 
•^'Ijpscens,  330  ;  atrophicans  cen- 
tralis of  Kuhnt,  340. 

Retinoscopy,  452 ;  with  plane 
mirror,  455,  459  ;  with  concave 
mirror,   456. 

Retro-bulbar  nem-itis,  345,  347. 

Retroflexion  of  iris,  213. 

Rheumatic  paralysis,  488. 

Rhinorrhoea,  persistent  cerebro- 
spinal, with  optic  neuritis,  349. 

Rodent  ulcer  of  eyelids,  551. 

Romer's"''treatment  of  serpiginous 
!ilcers,^127. 


044 


INDEX. 


Rontgen  rays,  Mackenzie  David- 
son's method  for  employing,  305. 

Rontgen  rays,  treatment  of  rodent 
ulcer,  552. 

Royal  Army  iNIedical  Corps,  625. 

Royal  Irish  Constabulary,  vision  re- 
quired for,  631. 

Royal  Navv,  vision  required  for. 
627. 

Sach's  operation  for  foreign  body 
in  vitreous,  311. 

Ssemisch's  incision  for  corneal  ulcers, 
127. 

Sarcoma  carcinomatosum  of  uveal 
tract,  220  ;  of  conjunctiva,  100  ; 
of  eyelids,  553. 

Schiotz's  tonometer,  236. 

Schlemm's  canal.  212. 

Scissors  movement  in  retinoscopv, 
459. 

Sclerectomy,  anterior,  252  ;  with 
trephine,  253. 

Scleritis.  brawny  or  annular,  168  ; 
deep,  166. 

Sclerosis,  disseminated,  of  brain 
and  cord,  372;  dii^use,  of  brain. 
374  ;  disseminated,  346  ;  of 
retinal  vessels,  323. 

Sclerotic,  blue  colour  of,  172  ; 
diseases  of  the,  164 ;  syphilitic 
gumma  of  the.  167  ;  tubercle  of 
the,  167  ;  tumours  of  the,  168  ; 
pigment  spots  in,  168  ;  injuries 
of,  168 ;  ruptures  of  the.  168 ; 
perforating  wounds  of  the.  170  ; 
staphyloma  of  the.  171  ;  con- 
genital defect  of  the,  172  ;  punc- 
ture of,  in  detached  retina,  338  ; 
coloboma  of  the,  172  ;  transillu- 
minator,  218. 

Sclerotomy,  posterior,   250. 

Scopolamine,  181. 

Scotoma,  central,  22  ;  paracentral, 
22  ;  annular  or  ring,  22  ;  posi- 
tive, 24  ;  negative,  24  ;  absolute. 
24  ;  relative,  24  ;  crescentic 
para-central,  242  ;  scintillating. 
390. 

Sense  of  fusion,  473. 

Seventh  nerve,  paralysis  of,  504. 

Shadow  test,  or  retinoscopy,  452. 

Sideroscope,  304.^307. 

Siderosis,  224. 
Sight,  sense  of,  10. 
Sixth'nerve,  paralysis  of,  503. 
Skin^  transplantation,  Wolfe  's 
method  of,  576. 


Snell's  electro-magnet,  308. 

Snellen's  coloured  types,  394 ;  oper- 
ation for  entropion,  569  ;  sutures, 
572. 

Snow-blindness,  332. 

Solid  oedema,  542. 

Sophol,  54. 

Spaces  of  fontana.  246. 

Spasmus  nutans,  540. 

Sphenoid  bone  and  antrum,  diseases 
of  the,  614. 

Spherical  aberration,  406. 

Spinal  amaurosis,   354. 

Spinal  cord,  diseases  and  injuries  of, 
379. 

Sporotrichosis,  86,   179. 

Spring  catarrh,  87. 

Staphyloma  of  cornea.  146  ;  partial, 
64  ;  total  64,  147  ;  leucomatous. 
147  ;  operations  for,  147 ;  pos-. 
terior,  422 ;  of  sclerotic,  171  ; 
anterior  or  ciliary,  171  ;  eqvia- 
torial,  171. 

Stellwag's  sign,  621. 

Stevens'  phorometer,  529. 

Stilling's  colour  test.  14. 

Stomach,  haemorrhages  for,  357. 

Strabismometer,  tangent,   517. 

Strabismus,  472  ;  apparent,  472  ; 
paralytic.  472  ;  concomitant.  472; 
latent,  472  ;  fixus,  506  ;  conver- 
gent, concomitant,  435,  506,  517  ; 
non-paralytic,  506  ;  single  vision 
in  concomitant,  511  ;  clinical 
varieties  of  concomitant  con- 
vergent, 513  ;  periodic.  513  ;  per- 
manent alternating,  513  ;  perma- 
nent monolateral,  513  ;  measure- 
ment of  convergent,  513 ;  measure- 
ment of,  513-517. 

Strabismus,  treatment  of  concomi- 
tant convergent,  517  ;  operative, 
519,  520  ;  optical,  517  ;  orthoptic, 
518;  subconjunctival  operations 
for,  522  ;  concomitant,  divergent, 
525. 

Streptothrix  in  lower  canaliculus, 
582. 

Stye,  545. 

Subconjunctival  cysticercus,  98. 

Subconjunctival  ecchymosis,   91. 

Subconjunctival     injections :      oxy- 
cyanate  of  mercury,   120  ;    saline 
solution,     120,    300  ;     potassium 
iodide,  55. 
Subconjunctival  serous  effusion,  91. 
Subcortical  alexia,  370. 
Subhyaloid  haemoi-rhages,  320. 


INDEX. 


645 


Sulcus  or  fornix  of  coiijunctiv^a,  42. 
Sulphate   of   zinc   in   conjunctivitis, 

Synibleplmron,  ()J>,  74,  l>2,  562  ; 
Harlan's  operation  for,  561  ; 
Teale's  operation  for,  563. 

Sympathetic  irritation,  193,  194; 
disseminated  chorioiditis,  201  ; 
ophthahnitis,  193,  195;  ophthal- 
mitis, prophylactic  operations  for, 
206  ;  ophthahnitis,  oj^tical  opera- 
tions for,  209;    ptosis,  501. 

Svnchysis,  299,  302  ;  scintillans, 
'  303. 

Synechia?,  posterior,  174,  199; 
complete  posterior,  175,  258  ;  cir- 
cular posterior,  175;  ring,  175, 
258;    total  posterior,  175. 

Synkinesis,   229. 

Syphilis  in  optic  neuritis,  345. 

Syphilitic  affections  of  eyelids,  551; 
gumma  of  ciliary  body,  188  ; 
tarsitis,  551. 

Syringomyelia,  382. 

Tabes  dorsalis,  347,  379 ;  pupillary 
alterations  in,  381. 

Tangent  strabismometer,  517. 

Tarsal  cyst,  546. 

Tarsitis  syphilitic.  551. 

Tarsoraphy,  561  ;  Priestly  Smith's 
method,  562  ;  Pfliiger's  method, 
562. 

Tattooing  cornea,  operation  of,  160. 

Teale's  operation  for  symblepharon, 
563. 

Telangiectic  tumours  O'f  eyelids,  547. 

Tenesmus,  182. 

Tenonitis,  598. 

Tenotomy  for  concomitant  con- 
vergent strabismus,  520. 

Tension,  intra-ocular,  in  glaucoma, 
236. 

Third  nerve,  paralysis  of,  481. 

Thomsen's  disease,  382. 

Thrombosis  of  central  artery  of 
retina,  325  ;  of  retinal  -vein,  327  ; 
of  cavernous  sinus,  502,  598. 

Tonometer,  Schiotz's,  236. 

Tower  skull,  344. 

Trachoma,  70  {see  (h-anular  Oph- 
tliahnia)  ;  cells,  71;  acute,  73; 
chronic,  73  ;  treatment  of  by 
caustics,  77 ;  mechanical  and 
operative,  78;  jequiritol,  81  ;  in- 
fusion of  jequirity,  79  ;  trichiasis 
in,  74,  565. 

Trichiasis,  565. 


Tul).M-clc  of  uveal  tract,  220  ; 
sclerotic,   167;    retina,  335. 

Tubercular  cyclitis,  189;  menin- 
gitis, 344  ;  disease  of  conjtmc- 
tiva,  84. 

Tuberculin,   187. 

Tumours,  malignant,  of  conjunc- 
tiva, 100  ;  of  the  caruncle,  101  ; 
of  the  sclerotic,  168;  intra-ocular, 
259  ;  telangiectic,  547  ;  of  lacri- 
mal gland,  593  ;  of  lacrimal 
gland,  tubercular,  594  ;  of  orbit, 
602  ;  symmetrical  of  orbits,  608  ; 
of  optic  nerve,  609. 

Ulceration  of  cornea,  infantile, 
with  xerosis  of  conjunctiva,  130. 

Ulcers,  of  the  cornea,  simple,  122; 
deep,  123;  serpiginous,  1 24  ;  ser- 
piginous, Romer's  treatment  of, 
127;  serpiginous,  Stemisch's  treat- 
ment of,  127  ;  pneumococcus,  124  ; 
Saemisch's,  124  ;  marginal  or  ring, 
128  ;  diplobacillary,  128  ;  rodent, 
129;  Mooren's,  'l29 ;  of  the 
cornea,  258  ;  of  the  conjinictiva, 
87. 

Uterus,  haemorrhages  from  the,  357. 

Uveal  tract,  diseases  of,  173  ;  in- 
jiu-ies  of,  211  ;  malformations  of, 
223  ;    new  growths  of,  216. 

Uveitis,  chronic,  186 ;  purulent, 
196. 

Vaccine,  atoxic  gonococcal,  06  ; 
autogenous,    186. 

Vaccine  vesicles  on  eyelids,  551. 

Van  Milligan's  operation  for  trichi- 
asis, 567. 

Vascular  na>vus,  99 ;  vernal  con- 
junctivitis, 87. 

Vertige  paralysant,  494. 

Vision,  acuteness  of,  14;  field  of, 
17 ;  defects  in,  20  ;  effect  of  prism 
on  binocular,  400  ;  field  of,  con- 
centric contraction  of,  385. 

Visual  aphasia,  370  ;  hallucina- 
tions, 371  ;    line,  3. 

Vitreous  humour,,  diseases  of,  298  ; 
purulent  inflammation  of,  298 ; 
non-purulent  inflammation  of, 
299  ;  varieties  of  opacities  in,  299  ; 
haemorrhage  in,  301 ;  fluidity  of,  or 
synchysis,  302  ;  foreign  bodies  in, 
303;  cysticercus  in,  311;  blood 
vessels  in,  312  ;  synchysis  scin- 
tillans of,  303  ;  mouches  volan- 
tes    in,    302  ;     prolapse    of,    284  ; 


646 


INDEX. 


detection  of  foreign  bodies  in, 
304  ;  by  Mackenzie  Davidson's 
method,  305 ;  by  sideroscope, 
304  ;  removal  of  foreign  bodies 
in  the,  308. 

Von  Graefe's  sign  in  exophthalmic 
goitre,   621. 

Von  Hippel's  disease,  323. 

Waxy  disc,  354. 

Weber's  probes,  585. 

Weeks'  operation  for  xeroph- 
thalmos,  617. 

Wenzel's  operation  for  total  pos- 
terior synechia,  209. 

\A'ernicke's  pupil-symptom,  369. 

Wolfe's  method  of  skin  trans- 
plantation, 576. 


Wood  alcohol,  352. 
Word-blindness,    370  ;     congenital. 

370. 
Worth's  amblyoscope,  518;    devio- 

meter,  515. 


[    Xanthelasma,  547. 
i    Xerophthalmos,   69,  96  ;  after  enu- 
cleation, 615. 

Xerosis,  74,  96  ;    bacillus.  48. 

X-rays,   81. 

Young-Helm  HOLTZ    theory    of 
colour  vision,   11. 


Ziegler's  iridotomy  operation,  292. 


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